Eur J Health Econ DOI 10.1007/s10198-015-0677-x

ORIGINAL PAPER

Economic evaluation of a telephone- and face-to-face-delivered counseling intervention for smoking cessation in patients with coronary heart disease Nadine Berndt • Catherine Bolman • Lilian Lechner • Wendy Max • Aart Mudde Hein de Vries • Silvia Evers

•

Received: 8 July 2014 / Accepted: 23 February 2015 Ó Springer-Verlag Berlin Heidelberg 2015

Abstract Objective This study examined the cost-effectiveness and cost-utility of two smoking cessation counseling interventions differing in their modality for patients diagnosed with coronary heart disease from a societal perspective. Methods In a randomized controlled trial conducted in Dutch hospital wards, cardiac patients who smoked prior to admission were allocated to usual care (n = 245), telephone counseling (n = 223) or face-to-face counseling (n = 157). The counseling interventions lasted for 3 months and were complemented by nicotine patches. Baseline histories were obtained, and interviews took place 6 months after hospitalization to assess self-reported smoking status and quality adjusted life years (QALYs). Incremental cost-effectiveness ratios per quitter and costutility ratios per QALY were calculated and presented in acceptability curves. Uncertainty was accounted for by sensitivity analysis. Results Using continued abstinence as the outcome measure showed that telephone counseling had the highest probability of being cost-effective. Face-to-to-face

counseling was also more cost-effective than usual care. No significant improvements and differences in QALYs between the three conditions were found. Varying costs and effect estimations revealed that the results of the primary analyses were robust. Conclusions Assuming a willingness-to-pay of €20,000 per abstinent patient, telephone counseling would be a highly cost-effective smoking cessation intervention assisting cardiac patients to quit. However, the lack of consensus concerning the willingness-to-pay per quitter impedes drawing firm conclusions. Moreover, studies with extended follow-up periods are needed to capture late relapses and possible differences in QALYs.

N. Berndt
C. Bolman
L. Lechner
A. Mudde Faculty of Psychology and Educational Sciences, Open University of the Netherlands, POB 2960, 6401 DL Heerlen, The Netherlands

H. de Vries Department of Health Promotion, School for Public Health and Primary Care (CAPHRI), Maastricht University, POB 616, 6200 MD Maastricht, The Netherlands

N. Berndt (&) Cellule d’expertise me´dicale, Inspection ge´ne´rale de la se´curite´ sociale, Le Gouvernement du Grand-Duche´ de Luxembourg, POB 1308, 1013 Luxembourg, Luxembourg e-mail: [email protected]

S. Evers Department of Health Services Research, School for Public Health and Primary Care (CAPHRI), Maastricht University, POB 616, 6200 MD Maastricht, The Netherlands

W. Max Institute for Health and Aging, Department of Social and Behavioral Sciences, University of California, San Francisco, 3333 California Street, Suite 340, San Francisco, CA 94118, USA

Keywords Coronary heart disease
Smoking cessation
Quality of life
Telephone counseling
Face-to-face counseling
Economic evaluation JEL Classification

I00
I12
I19
Z00

S. Evers Department of Public Mental Health, Trimbos Institute, Netherlands Institute of Mental Health and Addiction, POB 725, 3500 AS Utrecht, The Netherlands

123

N. Berndt et al.

Introduction Smoking cessation is still the most effective action to improve the disease prognosis of coronary heart disease (CHD). It decreases the annual risk of mortality and reoccurrence of coronary events, reduces hospitalization rates, and improves the health status of cardiac patients [1– 4]. Cost-of-illness studies reveal that the economic burden from smoking resulting in cardiac disease is considerable [5]. Because there is a strong correlation between disease severity and use of healthcare services, improving disease prognosis through smoking cessation is likely to reduce cardiac disease-related healthcare costs [6, 7]. Low- to medium-intensity smoking cessation interventions for patients diagnosed with CHD have already been implemented. Yet, these interventions show only weak effects on increasing smoking abstinence rates permanently [8–12], and full implementation is often not feasible in the cardiac nursing unit [13–17]. Consequently, smoking cessation guidelines, such as the US clinical practice guideline and the Dutch treatment guideline for tobacco use and dependence, recommend high-intensity smoking cessation treatment [18, 19], preferably delivered in the outpatient setting by competent health professionals [20, 21]. Multiple-contact telephone counseling (TC) and face-toface counseling (FC) are examples of high-intensity smoking cessation behavioral interventions that have been shown to be effective in general populations of smokers [22, 23]. Significant effects of supportive telephone contacts for cardiac patients to quit smoking have been demonstrated in a few studies [24–27], while the effectiveness of behavioral counseling interventions for cardiac patients varies with their intensity [8, 28]. A review on smoking cessation trials in hospitalized patients found that intensive counseling, initiated during hospitalization with follow-up for at least 1 month after hospital discharge, significantly increased quit rates (RR 1.37, 95 % CI 1.27–1.48, 25 trials). The review did not find a significant benefit for less intensive counseling. However, adding nicotine replacement therapy (NRT) to intensive counseling increased quitting compared with counseling alone (RR 1.54, 95 % CI 1.34–1.79, six trials) [29]. Stead and Lancaster [30] also found that a combination of behavioral and pharmacological support almost doubled the likelihood of successful quitting compared to the likelihood of quitting when receiving only brief support (RR 1.82, 95 % CI 1.66–2.00). Despite evidence of favorable outcomes of smoking cessation interventions combining behavioral and pharmacological support and their potential for reducing morbidity and mortality in patients with CHD [3], there is a lack of information about the cost-effectiveness of such interventions and their impact on healthcare costs [11]. Three previous studies reported the cost-effectiveness of smoking

123

cessation interventions for cardiac patients: a 21-year-old study, a 6-year-old study, and a modeling study from 2011 [31–33]. The 21-year-old study revealed that the classic nurse-managed behavioral smoking cessation program by Taylor and colleagues [27], in which a trained nurse provided a 1-h bedside counseling and seven follow-up calls after discharge, was more cost-effective than other medical therapies in patients with myocardial infarction with US$220 per life year gained [31]. The 6-year-old study evaluating a hospital-initiated smoking cessation program combined with follow-up calls in cardiac patients revealed that the incremental cost per life year gained by the smoking cessation program varied between €280 and 110, comparing favorably to other treatments, such as cholesterol-lowering medications [32]. The last published study on this subject by Lapado and colleagues [33] found similar outcomes by performing a modeling study of bedside counseling with supportive follow-up contact calls in patients hospitalized with acute myocardial infarction. Considering all healthcare costs, their cost-effectiveness was $4,350 per life year gained, whereas their cost-utility was $5,050 per QALY. All of the above-named studies suggest that supportive cessation counseling for smokers after discharge is inexpensive and potentially cost-effective in reducing the incidence of smoking and its related health and economic impact when compared to alternative treatments. However, no economic evaluation study has yet been conducted to investigate the cost-effectiveness of different delivery methods of smoking cessation counseling supplemented with pharmacological support in cardiac patients. Even if telephone-based smoking cessation interventions have yielded similar effectiveness as face-to-face counseling [8, 29], their implementation might be preferred from an economic point of view due to their presumed lower costs [34, 35]. Hence, in a time of rising healthcare costs and scarce resources, these interventions need further economic assessment in order to be able to select the most cost-effective alternative. Given the importance of this topic, this study details the cost-effectiveness and cost-utility of (1) a telephone-based smoking cessation counseling intervention supplemented with NRT, (2) a face-to-face smoking cessation counseling intervention supplemented with NRT, and (3) usual care to support patients hospitalized for CHD in their efforts to quit smoking from a societal perspective for a follow-up period of 6 months.

Materials and methods Setting Forty-six cardiac wards throughout the Netherlands were approached to assess whether they met the inclusion

Counseling intervention for smoking cessation in patients

criteria. Wards were invited to participate if they provided low care, did not offer any form of smoking cessation intervention to cardiac patients at the bedside, and if there was no outpatient smoking cessation department available at the hospital. Intensive care units, intermediate care units, and combined heart and lung units were excluded. Of the 46 wards approached, eight met all the relevant criteria and agreed to participate. The study protocol was approved by the Dutch Medical Research Ethics Committee (MERC) of the VU medical center Amsterdam. After approval by this MERC [36], the MERCs and/or board of directors of each hospital endorsed the execution of the study. The study was registered with the Dutch Trial Registration (NTR2144). Design The study used a pretest-post-test experimental intervention design. Crossover randomization was applied at the cardiac ward level in which the conditions were implemented serially. All cardiac wards first provided usual care (UC) and subsequently the two experimental conditions one after the other, while half of these wards implemented the experimental conditions in reverse order. Accordingly, after having implemented UC, four of the hospitals were randomly allocated to the telephone-based counseling intervention (TC) and thereafter implemented the face-toface counseling intervention (FC), whereas the other four hospitals were allocated to FC and thereafter implemented TC. After each condition there was a 1-month washout period during which no patients were included. The current design avoided contamination of the study groups and the hospital staff. Selection of patients Ward nurses and cardiologists received instructions for the study and a flow chart with the inclusion and exclusion criteria for eligible patients. Patients who smoked on average C5 cigarettes per day prior to admission or quit smoking less than 4 weeks prior to admission, were C18 years of age, were admitted to the cardiac ward for less than 96 h, and were hospitalized because of a CHD following the standards of the ICD-10 [37] were included by ward nurses. Patients with language limitations, cognitive impairments, and a medically unstable cardiac condition were excluded. In total, 625 patients agreed to take part, and nurses obtained written informed consent. Of these patients, 245 were assigned to the UC condition, 223 to the experimental condition of TC, and 157 to the experimental condition of FC (see Fig. 1). Prior to the start of the study, a sample size

calculation was conducted. This assumed an a = 0.05 and b = 0.20 with 1-b = 0.80 power, a medium abstinence rate of 60 % in the TC and FC group against 43 % in the UC group 6 months after baseline, and a 15 % attrition rate. Adjustment for potential baseline confounding variables reduced the sample size by 30 % resulting in a total number of 155 patients per group. It was attempted to recruit more patients to increase the statistical power. Protocol for experimental interventions Usual care (UC) for smoking cessation in-hospital All patients received standard in-hospital treatment for smoking cessation, which consisted of an assessment of their smoking behavior, the delivery of brief quit advice, and occasionally the provision of an informational brochure. Patients allocated to the UC group received no additional smoking cessation care. Telephone counseling (TC) plus NRT TC started within 1 week after enrolment of the patient and was provided by professional telephone counselors from the Dutch Expert Center for Tobacco Control. Prior to the counseling sessions, nurses on cardiac wards followed the Ask–Advise–Refer strategy [20, 21] and referred patients to TC. TC lasted for 3 months and consisted of seven telephone calls of 10–15 min each. All telephone counselors received financial compensation. In addition to TC, ward nurses provided the patient with nicotine patches and an information sheet on their use. Nicotine patches were used because they have been proven to be safe for cardiac patients [38, 39] and similarly effective as medical pharmacotherapy [40, 41]. Eligible patients who smoked more than ten cigarettes a day before admission received the patches [42] for 8 weeks at no cost when indicated by the cardiologist. Face-to-face counseling (FC) plus NRT The FC intervention had a structure and content comparable to TC. The main differences between the counseling methods were the provider and delivery method, and the duration of the counseling. The Ask–Advise–Refer strategy as applied by ward nurses and the delivery of the nicotine patches were identical to the procedure as used in TC. The counselors were nurses who were trained in providing cessation counseling. FC lasted 3 months, consisted of six face-to-face sessions of 30–45 min each, and ended with a follow-up call 5 weeks after the last session. All counselors received financial compensation.

123

N. Berndt et al.

8 parcipang Dutch cardiac wards

Enrollment Dec ’08 – June ’11

Cross-over randomisaon at the ward level (N = 625)

Allocaon Paents allocated to Usual Care (n = 245)

Follow-up June ’10 – Jan ’12

Paents allocated to Telephone Counselling + NRT (n = 223)

Paents allocated to Face-to-face Counselling + NRT (n = 157)

Received UC (quit advice by cardiologist (+ brochure))

Received UC + 7 TC sessions for 3 months + 8 weeks NRT

Received UC + 7 FC sessions for 3 months + 8 weeks NRT

n = 15 refused to parcipate; n = 10 died; n = 24 not reached

n = 14 refused to parcipate; n = 5 died; n = 34 not reached

n = 15 refused to parcipate; n = 2 died; n = 17 not reached

Post-measurement at 6 months (n = 196)

Post-measurement at 6 months (n = 170)

Post-measurement at 6 months (n = 123)

n = 170 included for all analyses & n = 212 for intenon-to-treat analyses

n = 122 included for all analyses & n = 155 for intenon-to-treat analyses

Analyses n = 195 included for all analyses & n = 227 for intenon-to-treat analyses

Fig. 1 Flow diagram of the experimental study testing two intensive smoking cessation interventions in cardiac patients. (NRT nicotine replacement therapy, in this trial nicotine patches offered to eligible patients)

Baseline and follow-up procedure and measurements At hospital admission, nurses administered a written questionnaire to patients and recorded relevant patient data on a separate form. Six months after discharge (T1), patients were interviewed by telephone by members of a professional call agency to obtain follow-up data. Telephone interviews were conducted in order to assure ‘‘blinding’’ of the outcome data and to decrease the likelihood of attrition. Data were obtained for 489 patients (78.2 %) at T1 (UC n = 196, TC n = 170, FC n = 123) (see Fig. 1). Measurement of patient-related data The baseline measurement (T0) assessed factors related to smoking cessation among cardiac patients. These included demographics, disease diagnosis, and smoking-related

123

factors such as nicotine dependence level measured by the Fagerstro¨m Test for Nicotine Dependence [43]. Educational level was assessed and categorized as primary, secondary, or post-secondary education [44]. To measure smoking-related intention to quit, existing questionnaires were used [44, 45] based on social-cognitive models [46– 48]. Relevant costs and utilities were also assessed at T0. Measurement and valuation of costs The present economic evaluation was conducted from a societal perspective according to the methods set out in the Dutch guidelines for cost analyses [49] and pharmaco–economic research [50]. Healthcare costs, patient and family costs, and productivity losses were assessed using 3-month retrospective questions to minimize recall bias at T0 and T1 [51]. Due to the impact of a cardiac disease on patients’ general health status and well-being, all disease-related and

Counseling intervention for smoking cessation in patients

unrelated costs were included. The time horizon for the economic evaluation comprised 6 months, thus all costs assessed over the 3-month retrospective period were doubled at T1. This was done because continuous data collection imposes a burden on patients leading commonly to missing values and withdrawal [52–54]. Previous studies have revealed that intermittent data collection in at least 3 months during a year may offer good estimates of the actual (bi-) annual health expenditures [55]. Intervention costs consisted of all costs that could be attributed to the delivery of the intervention, such as the costs of providing quit advice by the doctor in charge (costs of UC), counseling time of the face-to-face and telephone counselors, training, counselor and patient manuals, and nicotine patches. Time lost by the patients while participating in the interventions and travel costs of the patients to visit the face-to-face coach were also included. The time spent on counseling per patient was recorded by the counselors. Costs for the development of the intervention as well as research-specific costs (i.e., costs for interviews at T1) were excluded. Healthcare costs included visits to a general practitioner’s or practice nurse’s office, inpatient and outpatient specialist care, paramedic consultations, mental health care, hospital readmissions, prescribed and over-the-counter medication, smoking cessation aids, prescribed and over-the-counter smoking cessation medication, stay in nursing care and rehabilitation homes, and other care. Respondents had to indicate at T0 and T1 what type of care they received and how often they had received it during the past 3 months. At T1, patients were also asked about reasons for hospital readmissions, and use of cardiac rehabilitation. For cardiac rehabilitation, each patient was asked to specify the number of sessions and minutes per session. The Dutch manual for cost valuation in healthcare research was used to value healthcare [49]. Standardized prices were used, but when these were unavailable, real costs or average tariffs were used to estimate costs. Costs of medication, including smoking cessation medication, were calculated based on daily defined dosage and average insurance coverage [56]. The medication costs included 6 % value added tax, prescription charges for prescribed medication and clawback, a lawful discount percentage to be subtracted from medication prices by pharmacists. In the case of uncertainty, the lowest medication cost price was applied. Productivity costs were only assessed at T1 and related to absenteeism and presenteeism, and were based on modules of the productivity and disease questionnaire (PRODISQ) [57]. Productivity losses for paid work were calculated according to mean income valuation, and differences were made in productivity loss valuation for men and women [49].

Patient and family costs consisted of travel costs, paid and informal care, costs for utilities as a result of the patient’s health state, and productivity losses for daily activities (unpaid work). The number of visits to each healthcare provider was assessed at T0 and T1 and information was obtained about the number of journeys to each particular healthcare provider. Travel distances to healthcare providers and parking fees were estimated using the Dutch manual for cost valuation. Paid care and informal care were only assessed at T1. Paid care such as home care and domestic help were valued by average tariffs. Costs of informal care were valued by shadow prices for unpaid work. Productivity losses for daily activities were assessed at T1 by asking patients whether they spent fewer hours on regular daily activities such as supermarket purchases or gardening as a result of their health state. Productivity losses for daily activities were valued as costs for leisure time according to the Dutch manual [49]. Time lost due to visits to healthcare providers was excluded. Measurement and valuation of effects The primary outcome measure for the cost-effectiveness analysis was continued abstinence from smoking (0 = smoking; 1 = non-smoking). Continued abstinence was defined as being abstinent from smoking since the last counseling session. Secondary outcomes for the cost-effectiveness analysis were 7-day point prevalence abstinence and relative improvement in the number of cigarettes smoked at T0 and T1. The smoking outcomes were assessed at T1 by means of validated reliable questions [58]. Quality of life was the primary outcome measure for the cost-utility analysis, assessed in terms of Quality Adjusted Life Years (QALYs) based on the EuroQol EQ-5D utilities [59–61]. The EQ-5D consists of five dimensions (mobility, self-care, usual activity, pain/discomfort, anxiety/depression) on which patients had to indicate their personal health state (1 = no complaints; 2 = some complaints; 3 = many complaints). Utility scores were computed based on preferences that individuals may have for a particular set of health outcomes and ranged from -0.33 (worst imaginable health status) to 1 (perfect health status) using the Dutch tariff [62]. Utility scores assessed at T0 and T1 were used to compute an overall QALY score using the area under the curve method. The area under the curve is the duration of the health state (x-axis; 6 months) multiplied by the quality weight for the health state (y-axis; utility score), and represents the number of QALYs gained or lost [63]. For patients who died during the follow-up, a value of zero was assigned to utility weight for the health state.

123

N. Berndt et al.

Indexing and discounting costs and effects Costs were estimated in Euros for the index year 2011 (US$1.00 = €0.748). As costs in the Dutch manual for cost valuation were estimated for the year 2009 [49], these cost prices were inflated to the year 2011 using the consumer price indexes of the Dutch Central Institute for Statistics [64]. Since the follow-up period was \1 year, discounting costs and effects was not necessary. Statistical analyses To assess the comparability between the groups at baseline, ANOVAs with Tukey’s post hoc tests and v2 analyses were applied. Three respondents were excluded from the baseline analyses due to less than 80 % complete data. For patients who were assessed at baseline and at 6-month follow-up, missing data at T0 were replaced by imputation using respondents scores on the observation at T1 (next observation carried backward method) [55]. Patients who were lost to follow-up were excluded from the primary analysis (22.1 %). Since no information on the costs at T1 of these patients was available, a complete-cases analysis was regarded as the primary analysis to avoid inaccurate cost estimations for those patients lost to follow-up. Attrition analyses were conducted in order to determine possible selective loss at follow-up. Owing to the problem of highly positively skewed cost data, the three groups were compared with regard to their mean baseline costs and 6-month costs using non-parametric bootstrap resampling techniques (5,000 times) with 95 % confidence intervals (CIs) in percentiles [60]. For bootstrapping, the distribution of the cost data was derived from simulations of sampling with replacement from the original cost data. ANOVAs and v2 tests were used to compare the groups in terms of their smoking abstinence measures and QALYs assessed at T1. Incremental costeffectiveness ratios (ICERs) and incremental cost-utility ratios were then calculated by comparing the costs and effects (probability of continued abstinence and QALYs) of the usual care group to each intervention group, and by comparing the costs and effects of the intervention groups to each other. The robustness of the ratios was tested by non-parametric bootstrapping, mainly to account for sampling uncertainty [65]. The bootstrapped ICERs were depicted in a cost-effectiveness acceptability curve (CEAC) showing the probability that TC, FC, and UC are cost-effective using a range of values for the willingness-to-pay (WTP) [66]. The choice of treatment depends on the maximum amount of money that society is willing to pay for a gain in effectiveness, which is called the ceiling ratio. The ceiling ratio for the cost-utility of the interventions was set at

123

€20,000 per QALY. This is an accepted Dutch cut-off point for the WTP for each QALY gained by preventive interventions and is commonly used for evaluating this type of intervention in the Netherlands [67, 68]. For smoking cessation outcomes, no official societal WTP threshold is yet defined, though a similar ceiling ratio has been assumed in economic evaluations evaluating the cost-effectiveness of preventive smoking cessation and lifestyle interventions in the Netherlands [69–72]. Accordingly, the interventions were considered cost-effective at an incremental cost–utility ratio of €20,000 or less per QALY gained and at an incremental cost–effectiveness ratio of €20,000 or less per quitter. Uncertainty concerning the parameter estimates was dealt with by six sensitivity analyses and three explorative subgroup analyses with non-parametric bootstrapping techniques with 1,000 replacements. The sensitivity analyses (1) used 7-day abstinence, relative improvement in cigarettes smoked per day, and the QALY score based on the UK Dolan tariff as outcomes to allow international comparison [60]; (2) were performed for a conservative scenario in which all patients lost to follow-up were regarded as smokers (intention-to-treat); (3) excluded intervention noncompleters from the analysis (i.e., maximum two sessions missed) by applying the intention-to-treat principle; (4) included only intervention costs; (5) additionally included costs for nursing and rehabilitation center stay; and (6) extrapolated societal costs and effects to 12 months. Costs were extrapolated to 12 months by doubling the total costs of the 6-month period. Effects concerning continued abstinence at T1 were discounted with a proportion of 0.93 in the intervention groups and 0.94 in the UC group to match the decrease in abstinence rates from 6 to 12 months as reported by the most recent comparable study in cardiac patients [26]. Subgroup analyses were carried out for low vs. highly educated patients, for patients with low vs. high intentions to quit smoking, and for patients with low vs. high nicotine dependence at baseline. Therefore, the population was split on the basis of the median scores of these variables. Costeffectiveness acceptability frontiers were calculated for each scenario to estimate the probability that an intervention was cost-effective [73]. As regards the intention-to-treat scenarios, missing data for costs and EQ-5D items were replaced for lost patients by the last observation carried forward imputation, using patients’ scores at T0. When imputation was not possible due to missing data or because the relevant cost was not measured at T0, patients were excluded from the analysis (2.2 %). Patients who died (2.7 %) were also excluded. Bootstrap analyses were conducted using Microsoft Office Excel 2003. All other data were analyzed using SPSS version 19. The level for significance was set at p \ 0.05.

Counseling intervention for smoking cessation in patients

Results

Costs and effects at 6-month follow-up

Table 1 shows that at baseline, the three groups did not differ with respect to demographics and cardiac disease diagnosis. However, patients in the FC group reported significantly higher nicotine dependence than patients in the TC and UC group. At baseline there were no significant imbalances between the groups on costs and utilities. After 6 months, 489 (78.2 %) of the 625 respondents were followed up. Patients lost to follow-up were more often female (OR 1.86, 95 % CI 1.18, 2.95, p = 0. 01), reported to have made more quit attempts in the past (OR 1.67, 95 % CI 1.06, 2.62, p = 0.03), and were more likely to have a partner who smoked (OR 1.75, 95 % CI 1.11, 2.76, p = 0.02) than those who remained in the study (results not in a table).

As depicted in Table 2, no significant group differences were found in QALYs. v2 analysis, however, revealed significant differences in continued abstinence and 7-day abstinence between the three groups. A significantly higher proportion of patients in the TC and FC group achieved continued abstinence and 7-day abstinence compared to the proportion of abstinent patients in the UC group. Pairwise analysis showed that the TC group differed significantly for both continued abstinence [v2(1) = 9.58, p = 0.00] and 7-day abstinence [v2(1) = 8.76, p = 0.00] from the UC group. Moreover, the FC group differed significantly from the UC group for continued abstinence [v2(1) = 5.73, p = 0.02] and 7-day abstinence [v2(1) = 5.40, p = 0.02]. The TC and FC group did not differ in their abstinence

Table 1 Comparability of the UC (n = 243), TC (n = 222) and FC (n = 157) group at baseline Variables

UC

Age: M (SD)

TC

55.81 (11.91)

FC 56.53 (10.54)

p value

0.61

0.55

Gender (male): n (%)

183 (75.3 %)

163 (73.4 %)

111 (70.7 %)

1.04

0.60

Marital status: n (%) Married with/without children

161 (67.9 %)

151 (68.9 %)

102 (66.2 %)

0.31

0.86

76 (32.1 %)

68 (31.1 %)

52 (33.8 %)

Primary education

98 (41.5 %)

84 (38.2 %)

64 (41.6 %)

2.31

0.68

Secondary education

85 (36.0 %)

88 (40.0 %)

63 (40.9 %)

Single/divorced/widow

55.27 (10.53)

v2/F ratio

Education level: n (%)

Post-secondary education Paid job: n (%)

53 (22.5 %)

48 (21.8 %)

27 (17.5 %)

115 (49.9 %)

120 (55.8 %)

76 (51.1 %)

3.27

0.92

210 (86.8 %)

190 (86.0 %)

129 (83.2 %)

5.22

0.27

16 (6.6 %)

23 (10.4 %)

14 (9.0 %)

a

Disease diagnosis : n (%) ACS Stable angina Other/unspecified diagnosis Nicotine dependenceb: M (SD) Average cigarettes per day: M (SD) Intention to quitc: M (SD)

16 (6.6 %)

8 (3.6 %)

12 (7.7 %)

5.09 (2.34)

5.31 (2.10)

5.69 (2.00)

3.55

0.03*

19.67 (10.66)

21.90 (15.78)

22.31 (11.82)

2.44

0.09

7.49 (2.34)

7.52 (2.13)

7.48 (2.02)

0.02

0.98

Utility NL lamers tariff: M (SD)

0.971 (0.07)

0.968 (0.07)

0.967 (0.07)

0.19

0.83

Cost categoryd: M (SD) Healthcare costs

202.0 (273.2)

193.3 (258.1)

174.2 (244.8)

0.55

0.58

82.3 (232.5)

79.5 (267.6)

72.0 (123.5)

0.10

0.90

Prescribed and OTC medicatione Travel costs Operation costsf Total costs

19.2 (27.0)

18.2 (24.5)

17.0 (23.5)

0.38

0.69

4,753.5 (5,359.3)

6,019.1 (15,644.9)

4,468.1 (5,236.8)

1.32

0.27

5,057.0 (5,387.0)

6,310.1 (15,660.1)

4,731.2 (5,281.1)

1.33

0.26

Missing data are excluded, so n \ 622 for some analyses * p \ 0.05: for nicotine dependence, Tukey post hoc tests reveal that FC differs significantly from UC a

ACS acute coronary syndrome, includes (non-) ST elevation myocardial infarction

b

Range from 0 = low to 10 = high nicotine dependence level

c

Range from 2 = weak to 10 = strong intention to quit smoking

d

Presented costs are mean costs in € over a 3-month period (highly comparable to bootstrapped mean) OTC over-the-counter, including costs of smoking cessation aids

e f

Operation costs at the time of hospital admission

123

123 13.7 3,114.7 107.7 245.9 140.3 55.9 133.3 33.9 15.4 30.4 19.3 18.7 1,481.3 549.3 283.6 3,444.8 2,324.4 133.1 815.8 254.2 19.7 1,101.7 9,181.2

(11.56) (4,598.5) (143.1) (342.5) (367.8) (214.7) (269.7) (197.4) (62.9) (144.0) (108.9) (186.5) (3,660.2) (2,327.7) (785.1) (7,919.9) (4,038.6) (141.5) (2,151.3) (883.5) (129.2) (3,118.5) (11,041.0)

155.8 2,587.6 101.4 222.8 155.8 71.8 126.9 23.0 10.8 17.8 19.7 23.7 1,178.8 461.7 173.5 3,621.1 1,586.3 125.6 596.0 374.3 29.7 460.9 8,124.3

(84.1) (2,614.3) (152.5) (291.5) (388.5) (194.7) (235.4) (84.2) (25.1) (79.0) (81.5) (146.5) (1,579.4) (1,641.1) (170.3) (7,556.9) (2,918.6) (98.5) (1,859.5) (1,089.7) (150.2) (1,457.1) (8,830.7)

329.8 2,884.4 102.7 202.2 234.2 73.4 102.3 34.2 15.0 12.8 76.9 0.6 1,185.7 661.8 182.4 3,823.8 1,767.7 136.3 791.8 260.3 17.5 562.0 8,988.2

FC (125.5) (2,844.9) (151.0) (183.8) (367.8) (267.1) (218.1) (169.3) (35.7) (49.2) (637.4) (6.6) (1,650.4) (1,884.27) (185.5) (9,159.0) (2,909.4) (128.3) (1,899.5) (799.4) (85.6) (1,455.5) (10,677.4)

-141.9 486.9 7.4 23.6 -14.4 -15.5 6.2 10.9 4.6 12.5 -0.3 -4.9 303.3 92.7 109.7 -159.9 737.2 9.1 217.3 -120.3 -9.9 635.1* 1,055.6

(-153.0, -131.3)* (-156.6, 1,200.7) (-19.0, 33.6) (-32.5, 80.0) (-83.4, 53.6) (-53.5, 22.4) (-40.0, 53.5) (-14.3, 40.8) (-3.0, 14.0) (-7.2, 33.9) (-17.4, 18.6) (-33.9, 27.1) (-133.5, 841.1) (-257.5, 479.1) (27.6, 226.4) (-1,555.1, 1,281.1) (123.9, 1,351.8) (-12.0, 31.3) (-148.4, 580.4) (-305.8, 62.5) (-35.4, 15.1) (230.8, 1,079.0) (-707.3, 2,853.1)

UC–TC

TC

UC

63 (51.6) 67 (54.9) -16.13 (13.75)

Incremental costs (95 % CI)c

92 (54.1) 97 (57.1) -16.36 (20.89)

74 (37.9) 81 (41.5) -12.63 (12.17)

0.487 (0.02)

FC

Mean costs (SD)b

0.491 (0.02)

TC

0.489 (0.02)

UC

-316.2* 192.2 5.6 44.1 -92.6 -17.5 31.2 -0.2 0.4 17.4 -57.7 18.2 291.4 -109.0 100.7 -376.4 586.6 1.3 40.8 -6.8 2.1 538.3 182.5

UC–FC (-335.8, -296.5) (-387.2, 854.1) (-24.9, 34.7) (-5.9, 98.9) (-154.1, -30.5) (-70.9, 29.4) (-16.6, 78.6) (-37.6, 35.0) (-8.8, 10.5) (-0.8, 38.0) (-112.3, -11.7) (-0.2, 44.4) (-184.6, 834.6) (-508.9, 327.5) (22.2, 216.6) (-1,574.8, 868.9) (-84.4, 1,261.3) (-25.1, 27.8) (-355.6, 452.1) (-128.8, 122.9) (-17.9, 24.6) (103.2, 1,007.6) (-1,397.8, 1,837.9)

10.92 10.14

v2

174.2* 294.7 1.7 -20.6 78.8 2.0 -24.9 11.1 4.2 -4.9 57.0 -23.1 11.9 201.7 9.0 216.5 182.3 7.7 176.5 -111.1 -12.0 96.8 853.4

FC–TC

2.89

0.52

F ratio

(159.1, 188.4) (-121.3, 704.2) (-28.5, 32.5) (-68.8, 25.3) (-13.9, 177.4) (-44.2, 54.1) (-71.3, 21.8) (-13.7, 42.0) (-2.0, 11.0) (-18.4, 7.5) (-10.3, 176.6) (-44.2, -7.0) (-316.7, 347.6) (-160.5, 580.6) (-18.0, 35.2) (-1,020.8, 1,432.1) (-288.0, 603.2) (-16.3, 32.1) (-215.0, 566.1) (-276.4, 34.4) (-36.5, 10.1) (-204.0, 410.8) (-608.2, 2,288.4)

0.00 0.01 0.06

0.60

p value

d

c

b

a

The difference in mean costs between patient groups is based on 5,000 bootstrap replications; the upper and lower confidence limits are the 2.5th and 97.5th percentile OTC over-the-counter medication including additional smoking cessation aids

Presented costs are mean costs in € over a 6-month period (highly comparable to bootstrapped mean)

Based on the Dutch algorithm for the EuroQol (EQ-5D) scores

* p \ 0.05: for intervention costs, Tukey post hoc tests reveal that all groups differ significantly from each other. For lost time for daily activities, v2 analyses reveal that TC and UC differ significantly from each other

Intervention costs Healthcare costs General practitioner care Medical specialist care Paramedical care Mental healthcare specialist Medical officer (at work) Social assistance Nursing consult Life style coach Other health care Professional care (home visits) Heart revalidation care Hospital readmission stay Prescribed and OTC medicationd Total productivity loss costs (in €) Total patient and family costs Travel costs Informal care Paid home care Purchase of support materials Lost time for daily activities Societal costs

Cost category

QALY-EQ-5 Da: M (SD) Smoking abstinence rates Continued abstinence: n (%) 7-day abstinence: n (%) Change cigarettes a day: M (SD)

Effectiveness outcomes

Table 2 Effectiveness outcomes and mean costs per cost type of the UC (n = 195), TC (n = 170), and FC (n = 122) group at 6-month follow-up

N. Berndt et al.

Counseling intervention for smoking cessation in patients Table 3 Incremental cost-effectiveness ratios (ICERs) of the UC, TC, and FC group with a willingness-to-pay threshold of €20,000 Intervention

Costs per patienta

% abstinenceb

Incremental costs

Incremental effects

Incremental costs per quitterc

Continued abstinence UC

9,181.2

0.38 (0.61)

–

–

–

TC vs. UC

8,124.3

0.54 (1.93)

-1,056.9

0.16

Dominantd

FC vs. UC

8,988.2

0.52 (1.75)

-193.0

0.14

Dominant

TC vs. FC

8,124.3

0.54 (1.11)

-863.9

0.02

Dominant

Intervention

Costs per patient

QALYe UC

a

a

Quality of life

Incremental costs

Incremental quality of life

Incremental costs per QALYc

–

–

9,181.2

0.489

–

TC vs. UC

8,124.3

0.491

-1,056.9

0.002

FC vs. UC

8,988.2

0.487

-193.0

-0.002

TC vs. FC

8,124.3

0.491

-863.9

0.004

Dominant 96,500.0 Dominant

Presented costs are mean costs in €

b

The odds and odds ratio of being abstinent in parentheses

c

Calculated according to the formula ICER = (Ci-Cc)/(Ei-Ec)

d

Dominant = less costs, more effects compared to the other condition

e

Based on the Dutch algorithm for the EuroQol (EQ-5D) scores

rates (continued abstinence: v2(1) = 0.18, p = 0.68; 7-day abstinence: v2(1) = 0.13, p = 0.72]. Non-abstinent patients in the TC and FC group reported having smoked marginally fewer cigarettes since hospital discharge than patients in the UC group. The mean costs of the counseling interventions (plus NRT) were significantly higher than usual care. Moreover, with a mean difference of €174 the costs of the FC intervention were significantly higher than those of TC intervention. With regard to half annual costs due to lost time for daily activities per patient, a significant difference of €635 was found between the UC and TC group. Societal costs over the 6-month follow-up period were lowest in the TC group at €8,124, compared to €8,988 in the FC group and €9,181 in the UC group. Comparing costs and effects at 6-month follow-up The cost-effectiveness analysis of the societal costs per continued abstinent smoker (Table 3) indicated that TC dominated the other treatments: patients in the TC group had lower costs and a higher probability of abstinence than patients in the UC and FC group. FC had lower costs than UC, but higher costs than TC. The ICER revealed that FC dominated UC while it was dominated by TC assuming a WTP of €20,000 per continued abstinent smoker. As depicted in Fig. 2, the CEACs showed that for any monetary threshold value, TC was most likely to be the most effective treatment. Regarding the cost-utility analysis of the societal costs per QALY gained (Table 3), TC had lower costs and

slightly higher effects than both UC and FC, and thus dominated the other treatments. FC was dominated by UC, since FC was more costly and reached somewhat lower effects in QALYs gained compared to UC. Testing the robustness by secondary and subgroup analyses For the secondary analyses, TC was predominantly found to be dominant with probabilities of being cost-effective around 80 % in most scenarios (Table 4). Varying the outcome parameters of the primary cost-effectiveness scenario to either 7-day abstinence or relative improvement in cigarettes per day showed that TC was cost-effective regardless of the monetary threshold. Using the QALY based on the UK algorithm revealed that TC and FC had a probability of 69 and 21 % of being cost-effective, respectively. The intention-to-treat scenario resulted in minor differences in the CEACs of the primary analysis and revealed that TC was the most efficient counseling strategy at any monetary threshold (Fig. 3). When only intervention completers were included, FC was most effective up to a societal WTP of €12,500— above this monetary threshold TC had the highest probability of being cost-effective. In the scenario in which only intervention costs were included, for TC €888 and for FC €2,258 more would have to be paid per continued abstinent smoker in comparison to UC, and above a monetary threshold of €1,000 TC was revealed to be the most costeffective strategy for society. When costs for nursing and rehabilitation center stay were additionally included, TC

123

Probability cost-effective

N. Berndt et al. 100% 80% 60%

TC

40%

FC UC

20%

10 0 0 25 0 0 50 0 0 75 0 10 00 0 12 00 50 15 0 0 17 00 50 20 0 0 22 00 5 25 00 00 27 0 5 30 00 0 35 00 00 0

50

0

0%

Cost-effectiveness threshold: € / abstinent patient

Fig. 2 Base-case analysis and cost-effectiveness acceptability curves per abstinent patient expressed in € 2011 at 6-month follow-up

reached a 92 % probability of being the most cost-effective treatment strategy. Lastly, extrapolating costs and effects to 12 months increased the probability of FC being cost-effective with 18 vs. 81 % of TC. The CEACs in this scenario (as presented in Fig. 4) show that at any threshold value, TC outperformed FC. Subgroup analyses showed heterogeneity within the sample. First, for patients with a low educational level, TC dominated FC and UC, and was found to be the most costeffective strategy. However, for patients with a high educational level, FC was the optimal strategy with a probability of 49 % and a monetary threshold value of €20,000. Second, as regards the intention to quit smoking, FC was most cost-effective for patients with low quit intentions with probabilities ranging from 61 to 76 %, whereas for patients with high quit intentions, TC dominated UC and FC with a probability of 88 % of being cost-effective. Third, FC was found to be the preferred strategy for patients with low nicotine dependence with a probability of 61 % and a WTP above €10,000, whereas for patients with high nicotine dependence, TC outperformed its alternatives.

Discussion Main results To our current knowledge, this is the first study to determine the cost-effectiveness and cost-utility of different delivery methods of smoking cessation counseling in cardiac patients. The findings suggest that a telephone-delivered smoking cessation intervention complemented by NRT in cardiac outpatients has a high likelihood of being cost-effective. We showed that this intervention is more

123

cost-effective than face-to-face counseling using NRT and usual care, since it resulted not only in a higher probability of abstinence but also in lower societal costs for a 6-month period. Despite the improvements in abstinence rates, the telephone and face-to-face counseling interventions did not result in an improvement in QALYs. The QALYs gained per intervention were almost identical for the three groups 6 months after hospital discharge, impeding the choice between the interventions from the cost-utility perspective. In the primary cost-effectiveness analysis using a monetary threshold value of €20,000, the TC intervention strongly dominated the other strategies. The mean societal half-annual costs were lowest in this group, and with a probability of about 80 % of TC being the optimal choice using continued abstinence as the outcome measure, the results of this study show a clear preference for TC vs. FC and UC. As regards the outcomes of FC, it was less costeffective than TC, but it still had a higher probability of being cost-effective when compared to UC. In this regard, it should be noted that the intervention costs for TC were less than half of the costs of FC, both using NRT. The higher probability of being cost-effective as found for TC is thus likely to emanate from its lower intervention costs, since their effects were highly comparable at 6-month follow-up. Previous studies reported superior cost-effectiveness of TC over medical interventions, medications and face-to-face counseling as concerns smoking cessation [31–33, 74]. However, given the fact that literature on how much society is willing to pay per additional quitter is lacking, deriving conclusions and implications about the cost-effectiveness per abstinent patient is difficult. Results of the primary cost-effectiveness analysis were robust. When it concerned scenarios in which effects and costs were varied, the results suggested that TC remained the preferred treatment strategy for society, since in most scenarios TC had the highest probability of being costeffective for a WTP below €20,000 per quitter. Moreover, in those analyses in which all patients lost to follow-up were treated as smokers, and costs and effects were extrapolated to a longer follow-up period, TC revealed to have a cost-effectiveness that was superior to that of FC and UC. Subgroup analyses for patients with a low education and patients with a high quit intention supported the result that TC had the highest probability of being costeffective. On the other hand, for patients with a high education and patients with a low intention to quit smoking, FC appeared to be the optimal counseling strategy at any monetary threshold. As regards patients with low nicotine dependence, FC yielded to be the preferred strategy only above a monetary threshold of €10,000. Thus, for specific subgroups of cardiac patients, FC proved to be more cost-effective than its comparators.

9,181.2

Low intention to quit

High education

Low education

Subgroup analysesg

Extrapolation to 12-month follow-up

(8,546.3)

8,168.8

(12,333.6)

11,020.1

(10,027.2)

8,136.3

(22,082.0)

18,362.4

(41,821.2)

13,031.7

(11.6)

13.7

Intervention costs only

Including costs for nursing/rehabilitation center stay

–

(10,417.9)

7,533.0

(11,041.0)

9,181.2

(11,041.0)

9,181.2

(11,041.0)

Intervention completers (ITT)f

Intention-to-treat principle (ITT)e

QALY-EQ-5D with UK tariff

Improvement cigarettes a day

7-day abstinence

Secondary analyses

0.21

0.48

0.32

0.36

0.38

0.38

–

0.33

0.49

12.6

0.42

0.49

Base-case: QALY-EQ-5Dd (11,041.0)

0.38

9,181.2 (11,041.0) 9.181.2

Base-case: continued abstinence

Primary analyses

(8,888.6)

7,990.6

(10,732.8)

11,058.8

(7,076.2)

6,458.0

(17,661.4)

16,248.6

(8,836.0)

8,198.7

(84.1)

155.8

(8,620.1)

7,104.2

(8,161.5)

6,348.9

(8,830.7)

8,124.3

(8,830.7)

8,124.3

(8,830.7)

8,124.3

(8,830.7)

(8,830.7) 8.124.3

8,124.3

Costsa M (SD)

Costsa M (SD) Effects

TC

UC

0.47

0.57

0.52

0.50

0.54

0.54

0.51

0.43

0.49

16.4

0.57

0.49

0.54

Effects

(8,543.5)

6,860.1

(11,046.5)

10,488.2

(10,508.0)

7,983.7

(21,354.8)

17,976.4

(31,193.9)

11,728.9

(125.5)

329.8

(10,703.2)

7,388.8

(9,949.2)

6,748.9

(10,677.4)

8,988.2

(10,677.4)

8,988.2

(10,677.4)

8,988.2

(10,677.4)

(10,677.4) 8.988.2

8,988.2

Costsa M (SD)

FC

0.44

0.55

0.49

0.48

0.52

0.52

0.51

0.41

0.49

16.1

0.55

0.49

0.52

Effects

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

430.0 (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

2,257.9 (FC vs. UC)

888.2 (TC vs. UC)

Dominant (TC vs. FC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

Dominant (FC vs. UC) Dominant (TC vs. UC)

Dominant (TC vs. UC)

ICERb

TC: 39 %; FC: 61 %

FC at any threshold

UC: 11 %; TC: 40 %; FC: 49 %

FC at any threshold

TC: 84 %; FC: 16 %

TC at any threshold

UC: 1 %; TC: 81 %; FC: 18 %

TC at any threshold

TC: 92 %; FC: 8 %

TC at any threshold

\€1,000: UC, [€1,000: TC TC: 70 %; FC: 30 %

TC: 54 %; FC: 46 %

\€12,500: FC, [€12,500: TC

TC: 77 %; FC: 23 %

TC at any threshold

UC: 10 %; TC: 69 %; FC: 21 %

TC at any threshold

TC: 58 %; FC: 42 %

TC at any threshold

TC: 81 %; FC: 19 %

TC at any threshold

UC: 13 %; TC: 68 %; FC: 19 %

TC: 79 %; FC: 21 % TC at any threshold

TC at any threshold

CEAFc and probability of highest net benefit; %

Table 4 Results of the primary, secondary, and subgroup analyses for UC (n = 195), TC (n = 170), and FC (n = 122): costs and effects, incremental cost-effectiveness ratios (ICERs), and cost-effectiveness acceptability frontiers (CEAFs)

Counseling intervention for smoking cessation in patients

123

123 0.37

0.37

0.50

8,408.9

(8,923.6)

8,243.9

(8,785.2)

7,977.1

(8,906.6)

0.51

0.55

0.61

Effects

(11,199.6)

9,119.2

(10,291.5)

8,868.6

(11,984.5)

10,647.7

Costsa M (SD)

FC

0.42

0.63

0.57

Effects

Dominant (FC vs. UC)

Dominant (TC vs. UC)

Dominant (FC vs. UC)

539.2 (TC vs. UC)

10,674.3 (FC vs. UC)

Dominant (TC vs. UC)

ICERb

Attended at least five intervention sessions: TC n = 140, FC n = 101

Lost patients treated as smokers according to ITT principle: UC n = 227, TC n = 212, FC n = 155

Based on the Dutch algorithm for the EuroQol (EQ-5D) scores

Based on 1,000 bootstrap replications and with a willingness-to-pay threshold of €20,000; probability ranges specified at threshold values from €0 to 35,000

Calculated according to the formula ICER = (Ci-Cc)/(Ei-Ec); not calculated for dominated strategies

Presented costs are mean costs in € (highly comparable to bootstrapped mean)

(11,224.4)

9,775.4

(11,080.1)

8,728.4

(12,502.8)

9,900.50

Costsa M (SD)

Costsa M (SD) Effects

TC

UC

UC: 1 %; TC: 85 %; FC: 14 %

TC at any threshold

TC: 39 %; FC: 61 %

\€10,000: TC, [€10,000: FC

UC: 5 %; TC: 88 %; FC: 7 %

TC at any threshold

CEAFc and probability of highest net benefit; %

To compare patients with low (n = 283) vs. high education (n = 194), patients with low (n = 206) vs. high quit intentions (n = 276), and patients with low (n = 248) vs. high nicotine dependence (n = 229), the population was split into two categories using the median scores on each of these variables

g

f

e

d

c

b

a

High nicotine dependence

Low nicotine dependence

High intention to quit

Table 4 continued

N. Berndt et al.

Counseling intervention for smoking cessation in patients

Probability cost-effective

100% 80% 60%

TC

40%

FC UC

20%

0 50 10 0 0 25 0 0 50 0 00 75 10 00 0 12 00 50 15 0 0 1 7 00 50 20 0 0 2 2 00 5 25 00 00 27 0 5 30 00 00 35 0 00 0

0%

Cost-effectiveness threshold: € / abstinent patient

Fig. 3 Sensitivity analysis and cost-effectiveness acceptability curves per abstinent patient with intention-to-treat scenario expressed in € 2011 at 6-month follow-up

Probability cost-effective

1 0,8 0,6

TC FC UC

0,4 0,2

00 50 00 75 00 10 00 0 12 50 0 15 00 0 17 50 0 20 00 0 22 50 0 25 00 0 27 50 0 30 00 0 35 00 0

25

0

00

50

10

0

0

Cost-effectiveness threshold:

/ abstinent patient

Fig. 4 Sensitivity analysis and cost-effectiveness acceptability curves per abstinent patient with extrapolated costs and effects for 12-month follow-up expressed in € 2011

Previous studies In line with earlier findings [3, 8, 26], cardiac patients who received an intervention were more likely to be abstinent from smoking after 6 months than those who received usual smoking cessation care. Our result that TC and FC are similarly effective in enhancing abstinence rates is consistent with previous studies in the general population of smokers [11, 22, 23]. Comparable to the study of Lightwood and Glantz [7], immediate savings in healthcare costs after smoking cessation were realized in our study population of cardiac patients, since healthcare costs and total societal costs were lower in the intervention groups 6 months after discharge. The results of our study further confirmed that smoking cessation counseling interventions with regular supportive contact after discharge are costeffective and reduce the incidence of smoking, as previously suggested by Lapado and colleagues [33]. However, no previous study evaluated the cost-effectiveness of different delivery methods of multiple-contact counseling

complemented with pharmacotherapy. This study focused on TC and FC, both using NRT, in which TC was provided by the Dutch Expert Center for Tobacco Control, and FC was administered by nurses who were trained as cessation counselors. A previous study estimated the cost-effectiveness of similar interventions compared with current practice in the general population of Dutch smokers, and revealed a higher cost-effectiveness for counseling delivered by telephone than for counseling delivered face-toface [74, 75]. These findings are consistent with the results found in our study, since TC had a cost-effectiveness that was superior to that of FC. Limitations This study was subject to various limitations. Most importantly, a relatively short time horizon was used, and this might explain why we did not find any improvements in QALYs. Unlike the perceived health benefits of smoking cessation in patients with chronic obstructive pulmonary disease, such as less coughing, which are related to a direct improvement of health-related quality of life [76], patients with CHD might not perceive any direct health benefit in the short term and progress in quality of life due to withdrawal symptoms and difficulties of abandoning their smoking habit [77]. Economic evaluations of smoking cessation interventions in cardiac patients with longer time horizons would be valuable since effects in reduced readmission rates, improved quality of life, or reduced mortality could be identified with longer time spans [33]. Another reason that might explain why we did not find any improvement in QALYs is related to the generic measure we used [61]. Although the QALY EQ-5D allows comparisons across studies and countries [78], it has been shown to have a relatively low responsiveness in cardiac populations [79]. A greater number of health dimensions and more response levels might improve the responsiveness of the EQ-5D in cardiac populations [80]. Some other limitations imply a cautious interpretation of the results of this study. First, the FC counselors appeared to be newly trained cessation counselors, meaning that they might have had less experience in counseling cardiac patients to quit smoking. This may have colored our results and explain why FC appeared to be less (cost)effective than TC. Second, we assumed a societal WTP threshold of €20,000 per quitter conform previous studies assessing the cost-effectiveness of smoking cessation interventions in the Netherlands [69, 70]. However, it is uncertain which value society places upon each additional abstinent smoker, which impedes interpretation of the economic evaluation as presented in the current study. One could assume that the value gained for each quitter would exceed one QALY, as people who quit smoking on

123

N. Berndt et al.

average add several years to their life expectancy. Given the fact that there is no consensus on the maximum WTP for smoking cessation outcomes, no firm conclusion can be drawn about which counseling strategy would be the most cost-effective. Third, we used 6-month smoking abstinence as the outcome for the cost-effectiveness analysis, although smoking abstinence outcomes with a longer follow-up may generally be preferred. A longer time horizon might imply higher relapse rates and lower effects, and thus weaker cost-effectiveness. Nonetheless, smoking cessation rates have yielded to remain largely constant after a 6-month period, since relapse occurs mostly within the first 3 months after the quit attempt [26, 81]. We accounted for additional relapse from 6 to 12 months using estimates from the most comparable study [26]; in that study, 5 % of the intervention group and 3 % of the control group relapsed additionally from 6 to 12 months. Although these incidences of relapse may appear small, assuming a yearly 10 % additional relapse in the intervention groups and a yearly 6 % additional relapse in the usual care group, then, for example, abstinence rates may almost be equal after 5 years. A metaanalysis of randomized controlled trials testing NRT vs. no treatment in the general population of smokers estimated the average yearly incidence of relapse after 1 year to vary around 10 % [82]. In some studies, however, the relapse appeared to be less in later years [83, 84]. It is likely that fewer cardiac patients relapse in later years as well, decreasing concerns about the cumulative effect of late relapses. For those reasons, we believe that the effect of the presumed annual relapse estimates on the results of the cost-effectiveness should be considered preliminary. Fourth, we relied on self-reported smoking outcomes, which may have resulted in an overestimation of the abstinence rates [85]. Future studies should objectively validate smoking outcomes by biochemical testing. Fifth, the generalizability of the study may be limited since usual care varies from place to place. Although a comparison with usual care using NRT might have been relevant for the purpose of the economic evaluation, NRT was not included in usual care, because it is not considered usual care as applied in practice in the Netherlands. Sixth, although we did not find any significant differences between the three groups in terms of QALYs, patients allocated to the UC group might have been less healthy as reflected in higher healthcare usage and higher costs due to loss in daily activities. Finally, fewer patients were enrolled in the FC group than in the UC and TC group, resulting in a skewed distribution of patient inclusion in the three groups. This, in turn, may have reduced the statistical power to detect effects in the FC group compared to the other groups.

123

Conclusions and implications for future research The results of our study imply that smoking cessation counseling interventions complemented by NRT can be cost-effective in cardiac patients. Most notably, multiple contact telephone- and face-to-face-delivered counseling interventions are likely to result in short-term cost savings and greater smoking abstinence rates compared to usual care, for which TC emanates the highest probability of being cost-effective. However, for certain subgroups of cardiac patients, FC might be the preferred strategy. To enable proper interpretation of economic evaluations of smoking cessation interventions, consensus about acceptable societal WTP thresholds needs to be established. Hence, the societal WTP per abstinent smoker deserves particular attention in future research, since it remains questionable which is the best economic investment per quitter. Future studies also need to evaluate the QALY measure for specific patient populations in order to be able to capture (short-term) improvements in quality of life. Finally, the long-term impact on final end points, such as reduced readmissions and mortality, should be investigated. An economic modeling study might be valuable to project future health outcomes and costs of smoking cessation interventions. By aggregating data from other studies, comparators other than ‘‘usual care’’ may then also be included and more realistic estimates of smoking abstinence may be projected by accounting for relevant relapse rates. However, since a paucity of research on the incidence of relapse after 1 year is available, particularly in specific patient groups, studies that continue following abstinent smokers after 1 year are highly encouraged. Acknowledgments This project was financed by ZonMw, the Dutch Organisation for Health Research and Development (grant number: 50-50110-96-524). The authors acknowledge collaboration with the Dutch Expert Center for Tobacco Control (STIVORO), and the hospital offers and cardiac nurses of the participating hospitals. A particular thanks goes to all patients for their participation in this study and to Esther Kers for the data-entry. Conflict of interest The authors have no conflict of interest to disclose.

References 1. Critchley, J.A., Capewell, S.: Mortality risk reduction associated with smoking cessation in patients with coronary heart disease: a systematic review. JAMA 290(1), 86–97 (2003) 2. Gerber, Y., Rosen, L.J., Goldbourt, U., Benyamini, Y., Drory, Y.: Smoking status and long-term survival after first acute myocardial infarction a population-based cohort study. J. Am. Coll. Cardiol. 54(25), 2382–2387 (2009) 3. Mohiuddin, S.M., Mooss, A.N., Hunter, C.B., Grollmes, T.L., Cloutier, D.A., Hilleman, D.E.: Intensive smoking cessation

Counseling intervention for smoking cessation in patients

4.

5.

6.

7.

8.

9.

10. 11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

intervention reduces mortality in high-risk smokers with cardiovascular disease. Chest 131(2), 446–452 (2007) Van Spall, H.G., Chong, A., Tu, J.V.: Inpatient smoking-cessation counseling and all-cause mortality in patients with acute myocardial infarction. Am. Heart J. 154(2), 213–220 (2007) Max, W., Rice, D.P., Sung, H.Y., Zhang, X., Miller, L.: The economic burden of smoking in California. Tob. Control 13(3), 264–267 (2004) Froelicher, E.S., Sohn, M., Max, W., Bacchetti, P.: Women’s initiative for nonsmoking-VII: evaluation of health service utilization and costs among women smokers with cardiovascular disease. J. Cardiopulm. Rehabil. 24(4), 218–228 (2004) Lightwood, J.M., Glantz, S.A.: Short-term economic and health benefits of smoking cessation: myocardial infarction and stroke. Circulation 96(4), 1089–1096 (1997) Barth, J., Critchley, J., Bengel, J.: Psychosocial interventions for smoking cessation in patients with coronary heart disease. Cochrane Database Syst. Rev. 1, CD006886 (2008). doi:10.1002/ 14651858.CD006886 Bolman, C., de Vries, H., van Breukelen, G.: A minimal-contact intervention for cardiac inpatients: long-term effects on smoking cessation. Prev. Med. 35(2), 181–192 (2002) Rice, V.H., Stead, L.: Nursing intervention and smoking cessation: meta-analysis update. Heart Lung 35(3), 147–163 (2006) Rigotti, N.A., Munafo, M.R., Stead, L.F.: Smoking cessation interventions for hospitalized smokers: a systematic review. Arch. Intern. Med. 168(18), 1950–1960 (2008) Shishani, K., Sohn, M., Okada, A., Froelicher, E.S.: Nursing interventions in tobacco-dependent patients with cardiovascular diseases. Annu. Rev. Nurs. Res. 27, 221–242 (2009) Hennrikus, D.J., Lando, H.A., McCarty, M.C., Klevan, D., Holtan, N., Huebsch, J.A., et al.: The TEAM project: the effectiveness of smoking cessation. Prev. Med. 40(3), 249–258 (2005) Kotz, D., van Litsenburg, W., van Duurling, R., van Schayck, C.P., Wesseling, G.J.: Smoking cessation treatment by Dutch respiratory nurses: reported practice, attitudes and perceived effectiveness. Patient Educ. Couns. 70(1), 40–49 (2008) Sarna, L., Bialous, S.A., Wells, M., Kotlerman, J., Wewers, M.E., Froelicher, E.S.: Frequency of nurses smoking cessation interventions: report from a national survey. J. Clin. Nurs. 18(14), 2066–2077 (2009) Segaar, D., Bolman, C., Willemsen, M.C., Vries, H.: Determinants of adoption of cognitive behavioral interventions in a hospital setting: example of a minimal-contact smoking cessation intervention for cardiology wards. Patient Educ. Couns. 61(2), 262–271 (2006) Wetta-Hall, R., Ablah, E., Frazier, L.M., Molgaard, C., Berry, M., Good, M.: Factors influencing nurses’ smoking cessation assessment and counseling practices. J. Addict. Nurs. 16(3), 131–135 (2005) Dutch Institute for Health Care (Centraal BegeleidingsOrgaan (CBO)): Guideline treatment of tobacco dependence. Van Zuiden Communications, Alphen aan den Rijn (2009) Fiore, M.C., Jae´n, C.R., Baker, T.B., Bailey, W.C., Benowitz, N.L., Curry, S.J., et al. Treating tobacco use and dependence: 2008 update. US Department of Health and Human Services, Rockville. http://bphc.hrsa.gov/buckets/treatingtobacco.pdf (2008). Accessed 13 Sept 2013 Berndt, N.C., Bolman, C., de Vries, H., Segaar, D., van Boven, I., Lechner, L.: Smoking cessation treatment practices: recommendations for improved adoption on cardiology wards. J. Cardiovasc. Nurs. 28(1), 35–47 (2011) Orleans, C.T., Woolf, S.H., Rothemich, S.F., Marks, J.S., Isham, G.J.: The top priority: building a better system for tobacco-cessation counseling. Am. J. Prev. Med. 31(1), 103–106 (2006)

22. Lancaster, T., Stead, L.F.: Individual behavioural counselling for smoking cessation. Cochrane Database Syst. Rev. (2), CD001292 (2005). doi:10.1002/14651858.CD001292.pub2 23. Stead, L.F., Perera, R., Lancaster, T.: Telephone counselling for smoking cessation. Cochrane Database Syst. Rev. 3, CD002850 (2006). doi:10.1002/14651858.CD002850.pub2 24. Froelicher, E.S., Miller, N.H., Christopherson, D.J., Martin, K., Parker, K.M., Amonetti, M., et al.: High rates of sustained smoking cessation in women hospitalized with cardiovascular disease: the women’s initiative for nonsmoking (WINS). Circulation 109(5), 587–593 (2004) 25. Reid, R.D., Pipe, A.L., Quinlan, B., Oda, J.: Interactive voice response telephony to promote smoking cessation in patients with heart disease: a pilot study. Patient Educ. Couns. 66(3), 319–326 (2007) 26. Smith, P.M., Burgess, E.: Smoking cessation initiated during hospital stay for patients with coronary artery disease: a randomized controlled trial. CMAJ 180(13), 1297–1303 (2009) 27. Taylor, C.B., Houston-Miller, N., Killen, J.D., DeBusk, R.F.: Smoking cessation after acute myocardial infarction: effects of a nurse-managed intervention. Ann. Intern. Med. 113(2), 118–123 (1990) 28. Huttunen-Lenz, M., Song, F., Poland, F.: Are psychoeducational smoking cessation interventions for coronary heart disease patients effective? Meta-analysis of interventions. Br. J. Health Psychol. 15(4), 749–777 (2010) 29. Rigotti, N.A., Clair, C., Munafo`, M.R., Stead, L.F.: Interventions for smoking cessation in hospitalised patients. Cochrane Database Syst. Rev. 5, CD001837 (2012). doi:10.1002/14651858. CD001837.pub3 30. Stead, L.F., Lancaster, T.: Combined pharmacotherapy and behavioural interventions for smoking cessation. Cochrane Database Syst. Rev. 10, CD008286 (2012). doi:10.1002/14651858. CD008286.pub2 31. Krumholz, H.M., Cohen, B.J., Tsevat, J., Pasternak, R.C., Weinstein, M.C.: Cost-effectiveness of a smoking cessation program after myocardial infarction. J. Am. Coll. Cardiol. 22(6), 1697–1702 (1993) 32. Quist-Paulsen, P., Lydersen, S., Bakke, P.S., Gallefoss, F.: Cost effectiveness of a smoking cessation program in patients admitted for coronary heart disease. Eur. J. Cardiovasc. Prev. Rehabil. 13(2), 274–280 (2006) 33. Lapado, J.A., Jaffer, F.A., Weinstein, M.C., Froelicher, E.S.: Projected cost-effectiveness of smoking cessation interventions in patients hospitalized with myocardial infarction. Arch. Intern. Med. 171(1), 39–45 (2011) 34. Lichtenstein, E., Glasgow, R.E., Lando, H.A., Ossip-Klein, D.J., Boles, S.M.: Telephone counseling for smoking cessation: rationales and meta-analytic review of evidence. Health Educ. Res. 11(2), 243–257 (1996) 35. Reese, R.J., Conoley, C.W., Brossart, D.F.: The attractiveness of telephone counseling: an empirical investigation of client perceptions. J. Couns. Dev. 84(1), 54–60 (2006) 36. Central Committee on Research Involving Human Subjects (Centrale Commissie Mensgebonden Onderzoek (CCMO)): the review system in the Netherlands. http://www.ccmo.nl/en/ (2010). Accessed 12 May 2010 37. World Health Organization (WHO): International statistical classification of diseases and related health problems. 10th revision. WHO, Geneva (2010). http://www.who.int/classifications/ icd/en/. Accessed 21 Sept 2010 38. Hubbard, R., Lewis, S., Smith, C., Godfrey, C., Smeeth, L., Farrington, P., Britton, J.: Use of nicotine replacement therapy and the risk of acute myocardial infarction, stroke, and death. Tob. Control 14(6), 416–421 (2005)

123

N. Berndt et al. 39. Meine, T.J., Patel, M.R., Washam, J.B., Pappas, P.A., Jollis, J.G.: Safety and effectiveness of transdermal nicotine patch in smokers admitted with acute coronary syndromes. Am. J. Cardiol. 95(8), 976–978 (2005) 40. Hughes, J.R., Stead, L.F., Hartmann-Boyce, J., Cahill, K., Lancaster, T.: Antidepressants for smoking cessation. Cochrane Database Syst. Rev. 1, CD000031 (2014). doi:10.1002/ 14651858.CD000031.pub4 41. Stead, L.F., Perera, R., Bullen, C., Mant, D., Hartmann-Boyce, J., Cahill, K., Lancaster, T.: Nicotine replacement therapy for smoking cessation. Cochrane Database Syst. Rev. 11, CD000146 (2012). doi:10.1002/14651858.CD000146.pub4 42. Silagy, C., Lancaster, T., Stead, L., Mant, D., Fowler, G.: Nicotine replacement therapy for smoking cessation. Cochrane Database Syst. Rev. (3), CD000146 (2004). doi:10.1002/ 14651858.CD000146.pub2 43. Heatherton, T.F., Kozlowski, L.T., Frecker, R.C., Fagerstroem, K.O.: The Fagerstro¨m Test for Nicotine Dependence: a revision of the Fagerstro¨m Tolerance Questionnaire. Br. J. Addict. 86(9), 1119–1127 (1991) 44. Mudde, A.N., Willemsen, M.C., Kremers, S., de Vries, H.: Meetinstrumenten voor onderzoek naar roken en stoppen met roken. Dutch Expert Center for Tobacco Control, the Hague (2006) 45. De Vries, H., Mudde, A., Leijs, I., Charlton, A., Vartiainen, E., Buijs, G., et al.: The European Smoking Prevention Framework Approach (EFSA): an example of integral prevention. Health Educ. Res. 18(5), 611–626 (2003) 46. De Vries, H., Mesters, I., van der Steeg, H., Honing, C.: The general public’s information needs and perceptions regarding hereditary cancer: an application of the integrated change model. Patient Educ. Couns. 56(2), 154–165 (2005) 47. Fishbein, M., Ajzen, I.: Predicting and changing behavior: the reasoned action approach. Psychology Press, Taylor and Francis Group, New York (2010) 48. Prochaska, J.O., DiClemente, C.C.: Stages and processes of selfchange of smoking: toward an integrative model of change. J. Consult. Clin. Psychol. 51(3), 390–395 (1983) 49. Hakkaart-van Roijen, L., Tan, S.S., Bouwmans, C.A.M.: Handleiding voor kostenonderzoek: methoden en standaard kostprijzen voor economische evaluaties in de gezondheidszorg. College voor Zorgverzekeringen, Rotterdam (2010) 50. College voor Zorgverzekeringen: Guidelines for pharmaco–economic research, updated version. College voor Zorgverzekeringen, Diemen (2006) 51. Hassan, E.: Recall bias can be a threat to retrospective and prospective research designs. Internet J. Epidemiol. 3(2), p4 (2006) 52. Manca, A., Palmer, S.: Handling missing data in patient-level cost-effectiveness analysis alongside randomised clinical trials. Appl. Health Econ. Health Policy 4(2), 65–75 (2005) 53. Burton, A., Billingham, L.J., Bryan, S.: Cost-effectiveness in clinical trials: using multiple imputation to deal with incomplete cost data. Clin. Trials 4(2), 154–161 (2007) 54. Oostenbrink, J.B., Al, M.J.: The analysis of incomplete cost data due to dropout. Health Econ. 14(8), 763–776 (2005) 55. Hendriks, M.R., Al, M.J., Bleijlevens, M.H., van Haastregt, J.C., Crebolder, H.F., van Eijk, J.T., Evers, S.M.: Continuous versus discontinuous measurement of healthcare utilization. Med. Dec. Making 33(8), 998–1008 (2013) 56. College voor Zorgverzekeringen: Farmacotherapeutisch kompas: medicijnkosten. College voor Zorgverzekeringen, Diemen (2012). http://www.medicijnkosten.nl/. Accessed 09 Jan 2011 57. Koopmanschap, M., Meerding, W.J., Evers, S.M., Severens, H., Burdorf, A., Brouwer, W.: Manual for the use of the PRODISQ

123

58.

59.

60.

61. 62.

63.

64.

65.

66.

67.

68.

69.

70.

71.

72.

73.

74.

version 2.1. Erasmus MC. Institute of Medical Technology Assessment, Rotterdam (2004) Velicer, W.F., Prochaska, J.O.: A comparison of four self-report smoking cessation outcome measures. Addict. Behav. 29(1), 51–60 (2004) Drummond, M.F.: Introducing economic and quality of life measurements into clinical studies. Ann. Med. 33(5), 344–349 (2001) Drummond, M.F., O’Brien, B.J., Sculpher, M.J., Thorrance, G.W., Stoddart, G.L.: Methods for the economic evaluation of health care programmes (3rd revised edn). Oxford University Press, Oxford (2005) EuroQol Group: EuroQol-a new facility for the measurement of health-related quality of life. Health Policy 16(3), 199–208 (1990) Lamers, L.M., McDonnell, J., Stalmeier, P.F., Krabbe, P.F., Busschbach, J.J.: The Dutch tariff: results and arguments for an effective design for national EQ-5D valuation studies. Health Econ. 15(10), 1121–1132 (2006) Manca, A., Hawkins, N., Sculpher, M.J.: Estimating mean QALYs in trial-based cost-effectiveness analysis: the importance of controlling for baseline utility. Health Econ. 14(5), 487–496 (2005) Centraal Bureau voor Statistiek: Overview of consumer price indexes. Centraal Bureau voor Statistiek, Heerlen (2011). http:// statline.cbs.nl/statweb/. Accessed 12 Jan 2011 Sendi, P.P., Briggs, A.H.: Affordability and cost-effectiveness: decision-making on the cost-effectiveness plane. Health Econ. 10(7), 675–680 (2001) Fenwick, E., O’Brien, B.J., Briggs, A.: Cost-effectiveness acceptability curves-facts, fallacies and frequently asked questions. Health Econ. 13(5), 405–415 (2004) Boersma, C., Broere, A., Postma, M.J.: Quantification of the potential impact of cost-effectiveness thresholds on Dutch drug expenditures using retrospective analysis. Value Health 13(6), 853–856 (2010) Raad voor de Volksgezondheid en Zorg: Zinnige en duurzame zorg: transparante keuzen in de zorg voor een houdbaar zorgstelsel. Raad voor de Volksgezondheid en Zorg, Zoetermeer (2006) Smit, E.S., Evers, S.M., de Vries, H., Hoving, C.: Cost-effectiveness and cost-utility of internet-based computer-tailoring for smoking cessation: a trial-based economic evaluation among Dutch adult smokers. J. Med. Internet Res. 15(3), e57 (2013). doi:10.2196/jmir.2059 Stanczyk, N.E., Smit, E.S., Schulz, D.N., de Vries, H., Bolman, C., Muris, J.W.M., Evers, S.M.A.A.: An economic evaluation of a video and text-based computer-tailored intervention for smoking cessation: a cost-effectiveness and cost-utility analysis of a randomized controlled trial. PLoS One 9(10), e110117 (2014) Schulz, D.N., Smit, E.S., Stanczyk, N.E., Kremers, S.P.J., de Vries, H., Evers, S.M.A.A.: Economic evaluation of a web-based tailored lifestyle intervention for adults: findings regarding costeffectiveness and cost–utility from a randomized controlled trial. J. Med. Internet Res. 16(3), e91 (2014) Golsteijn, R.H.J., Peels, D.A., Evers, S.M.A.A., Bolman, C., Mudde, A.N., de Vries, H., Lechner, L.: Cost-effectiveness and cost–utility of a web-based or print-delivered tailored intervention to promote physical activity among adults aged over fifty: an economic evaluation of the active plus intervention. Int. J. Behav. Nutr. Phys. Act. 11(122) (2014) Stinnett, A.A., Mullahy, J.: Net health benefits: a new framework for the analysis of uncertainty in cost-effectiveness analysis. Med. Decis. Making 18(2 Suppl), S68–S80 (1998) Feenstra, T.L., Hamberg-van Reenen, H.H., Hoogenveen, R.T., Rutten-van Molken, M.P.: Cost-effectiveness of face-to-face

Counseling intervention for smoking cessation in patients

75.

76.

77.

78.

79.

80.

smoking cessation interventions: a dynamic modeling study. Value Health 8(3), 178–190 (2005) Feenstra, T.L., van Baal, P.H.M., Hoogenveen, R.T., Vijgen, S.M.C., Stolk, E., Bemelmans, W.J.E.: Cost-effectiveness of interventions to reduce tobacco smoking in the Netherlands. An application of the RIVM chronic disease model. RIVM rapport 260601003/2005. RIVM, Bilthoven (2005) Christenhusz, L.C., Prenger, R., Pieterse, M.E., Seydel, E.R., van der Palen, J.: Cost-effectiveness of an intensive smoking cessation intervention for COPD outpatients. Nicot. Tob. Res. 14(6), 657–663 (2012) Wiggers, L.C., Oort, F.J., Peters, R.J., Legemate, D.A., de Haes, H.C., Smets, E.M.: Smoking cessation may not improve quality of life in atherosclerotic patients. Nicot. Tob. Res. 8(4), 581–589 (2006) Knies, S., Evers, S.M., Candel, M.J., Severens, J.L., Ament, A.J.: Utilities of the EQ-5D: transferable or not? Pharmacoeconomics 27(9), 767–779 (2009) Goldsmith, K.A., Dyer, M.T., Schofield, P.M., Buxton, M.J., Sharples, L.D.: Relationship between the EQ-5D index and measures of clinical outcomes in selected studies of cardiovascular interventions. Health Qual. Life Outcomes 7(96) (2009). doi:10.1186/1477-7525-7-96 Moock, J., Kohlmann, T.: Comparing preference-based qualityof-life measures: results from rehabilitation patients with

81.

82.

83.

84.

85.

musculoskeletal, cardiovascular, or psychosomatic disorders. Qual. Life Res. 17(3), 485–495 (2008) Marlatt, G.A., Donovan, D.M.: Relapse prevention: maintenance strategies in the treatment of addictive behaviors. The Guilford Press, New York (2005) Hughes, J.R., Peters, E.N., Naud, S.: Relapse to smoking after 1 year of abstinence: a meta-analysis. Addict. Behav. 33(12), 1516–1520 (2008) US Department of Health and Human Services: The health benefits of smoking cessation. A report of the US Surgeon General. Centers for Disease Control, Office on Smoking and Health, Rockville (1990) Anthonisen, N.R., Connett, J.E., Kiley, J.P., Altose, M.D., Bailey, W.C., Buist, A.S., Conway, W.A., Enright, P.L., et al.: Effects of smoking intervention and the use of an inhaled, anticholinergic bronchodilator on the rate of decline of FEV1. JAMA 272(19), 1497–1505 (1994) Gorber, S.C., Schofield-Hurwitz, S., Hardt, J., Levasseur, G., Tremblay, M.: The accuracy of self-reported smoking: a systematic review of the relationship between self-reported and cotinine-assessed smoking status. Nicot. Tob. Res. 11(1), 12–24 (2009)

123