226 Original article
Work-related rehabilitation aftercare for patients with musculoskeletal disorders: results of a randomized-controlled multicenter trial Sebastian Knappa, Juliane Briesta and Matthias Bethgeb There is evidence that rehabilitation with a multidisciplinary focus on work-related demands effectively improves work ability and quickens return to work in patients with musculoskeletal disorders. There could be benefits to the transfer of work-related components into rehabilitation aftercare. We examined the effectiveness of an intensified work-related rehabilitation aftercare program compared with standard intensified rehabilitation aftercare in Germany on work ability. We randomly assigned 307 patients with musculoskeletal disorders from 11 rehabilitation centers to an aftercare program with work-related functional capacity training, work-related psychosocial groups, social counseling, relaxation training and exercise therapy (intervention group), or the usual aftercare program consisting of only exercise therapy (control group). The 6-month follow-up questionnaire was completed by 78.5% of patients. There was no statistically relevant betweengroup difference in follow-up primary (work ability) and secondary outcomes (e.g. health-related quality of life, sick leave duration). Significant improvements were observed within both the intervention and the control groups. Severely disabled participants in the intervention group had better
Introduction In Western countries, access to rehabilitation services is an established opportunity within the social security scheme (Saltychev et al., 2011; Tengland, 2011; Bethge et al., 2012). Improvement of work ability, participation in working life, timely return to work, and prevention of disability pensions are major aims of these programs. To achieve these objectives, early interventions, workplace involvement, and multiprofessional treatment seem to be essential components (Carroll et al., 2010; Hoefsmit et al., 2012; Schaafsma et al., 2013). One important element of a return to work strategy, especially in patients with musculoskeletal disorders, is physical conditioning. This is supported by recent findings of a systematic review, which shows that intense physical exercise is beneficial in reducing time to return to work in patients with chronic and subacute back pain (Schaafsma et al., 2013). In Germany, this awareness is reflected by a new guideline for work-related medical rehabilitation (WMR) (Streibelt and Buschmann-Steinhage, 2011; Bethge et al., 2013). This guideline recommends WMR, especially for patients with repeated and long-term sick leave episodes and patients with poor self-reported return to work prognosis. WMR 0342-5282 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
physical functioning and shorter sick leave duration after 6 months compared with severely disabled patients in the control group. A partial replacement of standard exercise therapy by a more work-related therapy does not seem to improve work ability superiorly. Improved aftercare treatment may require a focus on employer participation and involvement within the actual work environment. International Journal of Rehabilitation Research 38:226–232 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. International Journal of Rehabilitation Research 2015, 38:226–232 Keywords: aftercare, back pain, musculoskeletal diseases, randomizedcontrolled trial, rehabilitation a
Department of Rehabilitation Medicine, Hannover Medical School, Hannover and Section Rehabilitation and Work, Institute of Social Medicine and Epidemiology, University of Lübeck, Lübeck, Germany b
Correspondence to Sebastian Knapp, MA, Department of Rehabilitation Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany Tel: + 49 89 289 24421; fax: + 49 89 289 24452; e-mail: [email protected] Received 6 February 2015 Accepted 7 April 2015
programs follow the principles of functional restoration (Gatchel and Mayer, 2008) and work hardening (Schaafsma et al., 2013). These programs generally consist of functional capacity evaluation (Isernhagen, 1992; Bieniek and Bethge, 2014), functional capacity training, work-related psychosocial groups, and intensified social counseling. Although the current guidelines do not cover precise recommendations for activities and follow-up treatments after the completion of a WMR program, it is indicated that a structured aftercare based on the principles of WMR could be useful for these patients. In Germany, aftercare programs are usually provided in outpatient rehabilitation centers and are limited only to exercise therapy [intensified rehabilitation aftercare (IRAC)]. Between 2008 and 2010, the number of completed aftercare programs increased from 98 000 to 150 000 (Deutsche Rentenversicherung, 2012). Approximately 90% of these services are implemented following musculoskeletal rehabilitation. A recent multicenter survey observed that aftercare participants with severe limitations in workrelated functioning reported strong interest in additional work-related functional capacity training, work-related psychosocial groups, and social counseling (Briest and DOI: 10.1097/MRR.0000000000000117
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Work-related rehabilitation aftercare Knapp et al. 227
Bethge, 2013). Such treatments are currently not a regular part of conventional aftercare programs, which means that problems during the return to work process may not be responded to in a timely and professional manner. For example, exercise schedules need to be promptly adapted to discrepancies between job demands and individual physical capacity during the return to work process. To improve the effect of rehabilitation aftercare, we developed a novel program [intensified work-related rehabilitation aftercare (IWORAC)] that applies the already existing WMR principles to aftercare rehabilitation. The current study examines the effects of IWORAC on work ability and further secondary outcomes in comparison with standard IRAC in patients with musculoskeletal disorders.
work-related functional capacity training, work-related psychosocial groups, social counseling, and relaxation training. At least three of these four interventions were selected by the rehabilitation team and the patient according to the personal needs of the patient. The minimum duration of the work-related interventions of the IWORAC ranged from 7 to 12 h, that is 20–30% of the usual IRAC program. The new work-related treatments replaced the corresponding extent of exercise therapy that is usually provided in IRAC. Beyond the work-related interventions, IWORAC treatment followed the same program of exercise therapy as IRAC. IWORAC elements were tested and practiced during a previous implementation phase in all centers. Work-related functional capacity training
Materials and methods Study design
The effects of IWORAC were compared with those of usual IRAC in a randomized-controlled trial. Participants of the intervention group (IG) received IWORAC, which is explained in detail below. Participants of the control group (CG) were assigned to IRAC. Data collection was performed using questionnaires at the beginning of the aftercare program and 6 months later. The study protocol was approved by the ethics committee of the Hannover Medical School (ethics committee nr.: 6073) and data protection officers of the involved pension insurance agencies. The study is registered in the German Clinical Trials Register (DRKS00003360).
The work-related functional capacity training was supervised by physical therapists trained to perform functional capacity evaluations (Isernhagen, 1992; Bieniek and Bethge, 2014). Examples of exercises considered typical work-related physical tasks were lifting, carrying, or working overhead. If functional capacity training was not already performed during rehabilitation, the patients received an initial one-to-one briefing (60 min). During this initial session, functional capacity was individually assessed and compared with the job demands to define an appropriate training schedule. The training was performed in small groups of four to six participants during 5–12 sessions of 60 min each. The duration, intensity, and levels of difficulty were increased continuously from session to session (Staal et al., 2004).
Inclusion criteria
The patients included ranged in age from 18 to 65 years. Rehabilitation aftercare was approved because of one of the following ICD-10 diagnoses: M16, M17, M50, M51, M53, M54, M75, Z96.6, Z96.8, or Z98.8. All participants were employed and fulfilled at least one of the following criteria: (a) sick leave duration of at least 3 months within the last year, (b) still on sick leave at the beginning of the aftercare phase, or (c) poor subjective return to work prognosis according to the Wuerzburger Screening (Lukasczik et al., 2011). Control group
The traditional IRAC consists of 24 90-min sessions of strength and endurance training. Training sessions are performed in groups of not more than 15 patients. Patients start the aftercare program after discharge from previous rehabilitation and complete the program within 3 months. Intervention group
IWORAC was performed at the same frequency and duration as IRAC (24 sessions for 90 min each within 3 months). Specifically, work demands and work ability were targeted by adding established work-related rehabilitation modules (Bethge et al., 2011) to the program. These modules include
Work-related psychosocial groups
The patients learned methods and strategies to cope with relevant work-related and daily life problems. The psychosocial sessions were held in small groups of four to 10 participants. If the rehabilitation team and the patient decided to include a work-related psychosocial treatment, they chose at least two of the following six modules, which consisted of two 60-min sessions each. (1) Fit at work: Using an established questionnaire on work behavior and work-related attitudes, the patients gained knowledge of their individual work behavior. In addition, coping strategies for different behavior patterns were developed (Voltmer et al., 2011). (2) Conflict management: Patients discussed the different levels of communication (e.g. factual content, selfdisclosure, appeal, relation). Moreover, they learned to distinguish between secure, insecure, and aggressive behavior in conflict situations (Kaluza, 2007). (3) Emergency strategies: Strategies for the management of acute stress situations were taught in this module. The patients gained knowledge of their own typical stress symptoms (Kaluza, 2007). (4) Social support: The patients learned different patterns and mechanisms of relationships and learned to
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228 International Journal of Rehabilitation Research 2015, Vol 38 No 3
analyze relationships. In addition, the patients analyzed their own social network and developed ways to change unfavorable relationships (Heitzmann et al., 2008). (5) Work–life balance: The patients gained knowledge of work–life balance. Furthermore, they became aware of the roles that they assumed in their own life and learned to distinguish important from unimportant roles (Heitzmann et al., 2008). (6) Time management: Patients learned systematic strategies to plan daily and weekly activities. They also learned to rank the importance and urgency of tasks and to establish priorities accordingly (Kaluza, 2007). A manual that described contents and performance was developed. The trainers were prepared to conduct these modules in train-the-trainer sessions. Social counseling
Social counseling was conducted in a one-on-one session of at least 15 min. Its timing in the aftercare process depended on the topics to be clarified. Specifically, the social counseling session explored the status of progression of return to work and qualification measures initiated in the previous rehabilitation phase. Relaxation training
The patients refreshed the skills that they had learned during their initial rehabilitation and received support for transferring these techniques into daily life, including abbreviated techniques that could be performed easily at the workplace. The relaxation training was conducted for 6–12 sessions of 30 min each in groups of four to 10 participants. Outcomes Primary outcome
Work ability was measured by the Work Ability Index (WAI) (Ilmarinen, 2007). The WAI assesses the degree to which workers consider their state of health as adequate to cope with the demands of their job. The questionnaire comprises the following subscores: (1) current work ability compared with lifetime best, (2) work ability in relation to the demands of the job, (3) number of current diseases diagnoses, (4) estimated work impairment because of disease, (5) amount of sick leave during the past year, (6) self-prognosis of work ability 2 years into the future, and (7) mental resources. Item scores were summed to yield a total score. The total score ranges from 7 to 49, with higher scores indicating better work ability. Secondary outcomes
Health-related quality of life was measured using the eight subscales of the Short-Form Health Survey (SF-36) (Ware and Sherbourne, 1992). Depressive symptoms
were assessed using the nine-item depression module from the Patient Health Questionnaire (PHQ-9) (Kroenke et al., 2001). Pain intensity was measured by an average score of three 11-point numerical scales rating the current, strongest, and average intensity of pain (Jensen et al., 1999). The cumulated number of weeks of sick leave in the last 3 months was calculated to determine the level of participation in working life. Further variables
Sociodemographic information was assessed to characterize the recruited participants. Diagnoses and treatments during the programs were extracted from the physician’s discharge report. Randomization
Because of the successive recruitment of patients, randomization was performed in blocks with permuted block sizes to achieve maximal balance between both groups. Numerous brief lists (with block size of 2, 4 or 6) were generated using the STATA procedure ‘ralloc’ and then connected randomly to create randomization lists. These randomization lists were created for each rehabilitation facility. For the allocation, nontransparent, closed randomization envelopes were produced. Envelopes were marked by a unique study identification number to ensure that the study participants and envelopes were matched precisely. An enclosed document showed information on allocation. Sample size estimation
Sample size estimation was performed to confirm a standardized mean difference (SMD) of 0.3 (two-sided error probability: 5%; power: 90%). Assuming a correlation of r = 0.4 between the baseline and the follow-up measurement, a sample size of 396 participants for our analysis of the primary outcome was targeted. Statistical analyses
Sample characteristics and treatment precision (adherence to the treatment protocol) were analyzed by descriptive statistics. To quantify differences in treatment intensity between rehabilitation centers, intracluster correlation coefficients were calculated. To calculate these coefficients, the variance of a measurement is decomposed in a variance component that is related to the center and a variance component that is related to individual characteristics (Kerry and Bland, 1998). The intracluster correlation indicates the part of the variance that is explained by the center characteristics. If the treatment intensity is independent of the center, this coefficient should approach zero. Treatment effects on the primary and secondary outcomes were analyzed by generalized linear regression models that included a random intercept to account for the dependency of measures within the same rehabilitation center. Baseline scores of the dependent variable were included as covariates
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Work-related rehabilitation aftercare Knapp et al. 229
(Vickers and Altman, 2001). All participants were included and data were analyzed on an intention-to-treat basis. SMDs were calculated by dividing the regression coefficient of the treatment effect by the pooled SD of the follow-up measurements (Lipsey and Wilson, 2001). SMDs were interpreted according to Cohen’s effect size conventions (SMD ≥ 0.2: small; SMD ≥ 0.5: medium; SMD ≥ 0.8: large) (Lipsey and Wilson, 2001). To calculate intragroup effects to characterize the change between measurements, the mean differences of followup and baseline measurements were divided by the corresponding baseline SD [standardized effect size (SES)] (Kazis et al., 1989). In addition, treatment effect moderators were analyzed to clarify whether certain subgroups benefit more or less than others. In particular, we analyzed whether effects on secondary outcomes (e.g. physical functioning and sick leave duration) depended on baseline work ability. The modeling of the moderator effect was performed by a multiplicative interaction term of the treatment indicator and the z-standardized baseline WAI (Smeets et al., 2009). Treatment effects were calculated for low WAI scores (average WAI score − 1 SD), the average WAI score, and high WAI scores (average WAI score + 1 SD). All analyses were carried out using STATA, version 12 (Stata Corp LP, College Station, Texas, USA).
Results Recruitment and sample size
Patients were recruited between February 2012 and February 2013. In total, 307 patients agreed to participate in the study and were assigned to IG (n = 157) or CG (n = 150) (Fig. 1). The 11 rehabilitation centers recruited, on average, 28 patients (range: 10–44). The 6-month follow-up questionnaire was completed by 241 (78.5%) patients. A comparison between follow-up participants and nonparticipants showed no significant differences. The follow-up participants were slightly older and reported less pain. The total treatment duration during aftercare was similar (IG vs. CG: 34.9 vs. 31.4 h). Sample characteristics at baseline are summarized in Table 1. Approximately half of the patients were women (54.7%). The average age was 46.5 years (SD = 10.2). Around two-thirds of the aftercare interventions were approved because of ICD-10 diagnoses M50 to M54. About 70.1% of the patients were employed full time. At the beginning of the aftercare, three-fourths of the patients were still on sick leave. Sick leave duration before rehabilitation was, on average, 9.4 weeks (SD = 4.7). Two-thirds of the patients had very low WAI scores (7–27 points), indicating poor work ability. Both groups were similar in terms of the variables assessed.
Treatment credibility
On average, about 9 h (562 min) of the treatments of the IG were work-related interventions. This corresponded to a quarter of the total treatment dose of the aftercare program and was in accordance to the defined minimum amount of work-related modules as described in the treatment protocol (7–12 h). However, there was marked variance between the 11 cooperating facilities. Although two centers performed more than 17 h of specific workrelated interventions, in two other centers, less than 2 h of specific work-related interventions were completed. In four centers, the average treatment dose provided was close to the overall mean. Intracluster correlation coefficients for single treatment modules ranged from 0.33 to 0.49, indicating that ∼ 30–50% of the differences in the treatment dose provided were explained by the centers. Explanation by center was strongest for the treatment dose of workrelated psychosocial groups. The intracluster correlation coefficient for the overall work-related treatment dose was 0.43 [95% confidence interval (CI): 0.21–0.67]. Primary outcome
There was no statistically relevant difference in follow-up work ability between IG and CG in the intention-to-treat analysis (Table 2). Although no significant betweengroup differences could be identified, work ability improved with SES = 0.46 (95% CI: 0.29–0.62) considerably in the IG. Secondary outcomes
There were also no significant between-group differences for the secondary outcomes (Table 2). Patients of the IG showed reduced sick leave duration (SES = 1.38; 95% CI: 1.14–1.62) and better physical quality of life compared with baseline, for example physical role (SES = 1.11; 95% CI: 0.84–1.38). Moderator analysis
Analyses of the WAI as an effect modifier showed an additional benefit for IG patients with low WAI scores (Table 3). With increasing baseline limitations, that is lower WAI scores, the results of both groups differed stronger. Patients of the IG with low WAI scores showed a significant increase in their physical functioning (b = 7.58; 95% CI: 0.68–14.49) and a decrease in their sick leave duration (b = − 2.08; 95% CI: − 3.38 to − 0.33) compared with similar patients in the CG.
Discussion Patients attending IWORAC neither had better work ability than controls nor showed greater improvement on any of the secondary outcomes. Only very severely limited patients benefited from attending IWORAC compared with similar controls from IRAC.
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230 International Journal of Rehabilitation Research 2015, Vol 38 No 3
Fig. 1
Randomized (n = 307)
Patients assigned to IRAC
Patients assigned to IWORAC
(n = 150)
(n = 157)
Analyzed after 6 months
Analyzed after 6 months
(n = 120)
(n = 121)
Flow of patients. IRAC, intensified rehabilitation aftercare; IWORAC, intensified work-related rehabilitation aftercare.
Table 1
Sample characteristics at baseline IRAC
Sex: female (%) Age in years [mean (SD)] Diagnosis: M50-M54 (%) Full-time employed (%) Still on sick leave (%) Sick leave duration (past 3 months) [mean (SD)] Work Ability Index [mean (SD)] Good/very good work ability (%) (37–49 points) Moderate work ability (%) (28–36 points) Poor work ability (%) (7–27 points) Physical functioning (SF-36) [mean (SD)] Physical role (SF-36) [mean (SD)] Bodily pain (SF-36) [mean (SD)] General health (SF-36) [mean (SD)] Vitality (SF-36) [mean (SD)] Social functioning (SF-36) [mean (SD)] Emotional role (SF-36) [mean (SD)] Mental health (SF-36) [mean (SD)] Depressive symptoms (PHQ-9) [mean (SD)] Pain intensity [mean (SD)]
IWORAC
Total
n
Mean (SD) or %
n
Mean (SD) or %
n
Mean (SD) or %
150 150 150 147 149 137 143
52.7 46.9 (10.1) 57.3 74.1 77.9 9.3 (4.8) 24.8 (7.4) 4.9 31.5 63.6 54.7 (22.1) 13.5 (27.4) 33.1 (19.5) 53.4 (18.1) 44.3 (19.6) 58.6 (27.8) 53.0 (47.3) 61.0 (21.8) 7.5 (5.3) 5.8 (1.8)
157 157 157 154 157 146 140
56.7 46.9 (10.1) 64.3 66.2 79.0 9.5 (4.6) 24.8 (7.8) 7.1 31.4 61.4 55.2 (21.4) 12.2 (25.4) 33.1 (15.8) 51.6 (18.6) 43.2 (19.2) 60.2 (25.8) 54.3 (45.0) 60.2 (20.2) 7.7 (5.7) 5.7 (1.8)
307 307 307 301 306 283 283
54.7 46.5 (10.2) 60.9 70.1 78.4 9.4 (4.7) 24.8 (7.6) 6.1 31.4 62.5 54.9 (21.7) 12.8 (26.4) 33.1 (17.7) 52.5 (18.3) 43.7 (19.4) 59.4 (26.7) 53.7 (46.1) 60.6 (21.0) 7.6 (5.5) 5.7 (1.8)
149 149 150 150 150 150 149 150 150 148
157 154 157 154 157 157 151 157 154 153
306 303 307 304 307 307 300 307 304 301
IRAC, intensified rehabilitation aftercare; IWORAC, intensified work-related rehabilitation aftercare; PHQ, Patient Health Questionnaire; SF-36, 36-Item Short-Form Health Survey.
Intense physical conditioning programs have shown benefits in subacute and chronic pain patients in reducing time to return to work compared with usual care (Schaafsma et al., 2013). However, it is debatable whether treatment dose or content leads to reduced return to work time. Although several reviews indicate that a focus on work-related content can improve work ability and return to work (Tveito et al., 2004; Norlund et al., 2009; Carroll et al., 2010; Odeen et al., 2013; Schaafsma et al., 2013), most of the studies included compared comprehensive treatments against usual care. Consequently, dose and content are interrelated, and therefore, are very difficult to interpret independently.
Kool et al. (2005) and Kool et al. (2007) showed that a more function-centered rehabilitation program might be more appropriate than a pain-centered program in supporting return to work. However, function centering is a common characteristic of modern exercise treatment schemes and not solely a merit of work-related functional capacity training. This might explain why the stronger focus on work-related demands was not associated with improved work ability in our study. Nevertheless, the most apparent weakness of the established IWORAC program in comparison with other work-related rehabilitation programs that have successfully reduced the time to return to work (Loisel et al., 1997; Lambeek et al., 2010) is
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Work-related rehabilitation aftercare Knapp et al. 231
Table 2
Primary and secondary outcomes at the 6-month follow-up IG n
Work Ability Index Sick leave duration (past 3 months) Physical functioning (SF-36) Physical role (SF-36) Bodily pain (SF-36) General health (SF-36) Mental health (SF-36) Vitality (SF-36) Social functioning (SF-36) Emotional role (SF-36) Depressive symptoms (PHQ-9) Pain intensity
99 110 121 119 121 118 121 121 121 115 118 117
CG
EMM (SE) 29.0 2.6 63.7 41.0 44.3 54.0 63.3 48.2 67.3 64.1 7.3 4.9
(0.6) (0.5) (1.9) (3.6) (1.8) (1.4) (1.7) (1.8) (2.1) (3.8) (0.4) (0.2)
n 113 106 118 118 119 119 119 119 119 119 120 117
EMM (SE) 28.9 3.2 60.7 39.0 44.1 53.2 63.5 46.7 67.4 62.2 7.4 4.8
(0.6) (0.5) (1.9) (3.6) (1.8) (1.4) (1.7) (1.8) (2.1) (3.7) (0.4) (0.2)
b
95% CI
P
SMD
0.09 − 0.62 3.00 2.00 0.16 0.72 − 0.13 1.53 − 0.06 1.91 − 0.09 0.11
− 1.63 to 1.80 − 1.98 to 0.74 − 1.93 to 7.93 − 7.87 to 11.87 − 4.81 to 5.14 − 3.02 to 4.46 − 4.37 to 4.12 − 2.92 to 5.97 − 5.96 to 5.85 − 7.27 to 11.09 − 1.16 to 0.98 − 0.39 to 0.61
0.921 0.371 0.234 0.692 0.948 0.706 0.954 0.501 0.985 0.683 0.871 0.672
0.01 0.12a 0.12 0.05 0.01 0.04 − 0.01 0.07 0.00 0.04 0.02a − 0.04a
b, unstandardized regression coefficient; CG, control group; CI, confidence interval; EMM, estimated marginal mean; IG, intervention group; PHQ, Patient Health Questionnaire; SF-36, 36-Item Short-Form Health Survey; SMD, standardized mean difference. a Regression coefficient was multiplied by − 1; therefore, a positive standardized difference indicates a superior result for the IG.
Table 3
Comparison of IG versus CG by low, average, and high baseline WAI scores SF-36 physical functioning (n = 226)
Low WAI Average WAI High WAI
Sick leave duration (n = 205)
b
95% CI
P
b
95% CI
P
7.58 3.11 − 1.37
0.68–14.49 − 1.76 to 7.98 − 8.28 to 5.55
0.031 0.211 0.699
− 2.08 − 0.90 0.29
− 3.83 to − 0.33 − 2.13 to 0.34 − 1.47 to 2.04
0.020 0.155 0.750
Combined estimates for low WAI scores (average WAI score − 1 SD), average WAI score, and high WAI scores of the first measurement (average WAI score +1 SD) from regression models with multiplicative interaction of baseline WAI and treatment indicator. b, unstandardized regression coefficient; CG, control group; CI, confidence interval; IG, intervention group; SF-36, 36-Item Short-Form Health Survey; WAI, Work Ability Index.
that a stronger focus on job demands was realized without actual workplace involvement. Involving the actual workplace environment, by including meetings with supervisors, workplace visits, or cooperation with an occupational physician at the workplace or a case manager of the insurance agency, who coordinates the process of return to work, may increase the effectiveness of these programs. Recent studies confirmed that such developments are also feasible within the German rehabilitation setting (Schwarze et al., 2013). Currently, different aftercare strategies are tested and implemented in Germany. Structured aftercare in Germany, including IRAC and IWORAC, are compensatory strategies. This is because primary rehabilitation programs are too short and their treatment doses are too low to affect functional and work ability outcomes (Guzman et al., 2001). Aftercare attempts to compensate for this lack of appropriate treatment dose by offering additional exercise treatments. In the future, recognizing the effects of active workplace involvement could help to improve the effects of structured aftercare programs. Most importantly, work participation is not only determined by the individual’s functional capacity but a range of environmental factors (Hayden et al., 2009; Van den Berg et al., 2009). As well as the cooperation of rehabilitation facilities and social security agencies, the continuous involvement of employers might be required so that all stakeholders follow a mutually shared rehabilitation strategy
(Lambeek et al., 2010). As aftercare programs are usually performed in outpatient centers that are close to the homes and workplaces of participants, networks of rehabilitation facilities and employers are not hindered by long distances so that regular meetings and workplace visits are feasible. The results of the current study must be interpreted within the context of the following limitations. Primarily, despite an implementation phase before this study, adherence to the treatment protocol was poor in some centers. Second, the targeted sample size was not reached as recruitment was rather slow and financial support was restricted. However, an inspection of the effect sizes provides no hint that statistical significance failed because of a very small sample size. Third, the follow-up period of our analyses was rather short. A longer time frame might be needed to establish the potential benefit of rehabilitation programs with a stronger focus on work-related functional capacity than compared with other exercise schemes as a recent metaanalysis showed that between-group differences in workrelated outcomes increase in later follow-up measurements (Schaafsma et al., 2013). A 12-month follow-up will therefore examine whether the stronger focus on workrelated capacities is superior in the long term. These limitations are balanced by the following strengths. The internal and external validity of this study is strengthened by its randomized-controlled multicenter
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232 International Journal of Rehabilitation Research 2015, Vol 38 No 3
design. Randomization of patients prevented selection bias and yielded comparable study groups. Generalizability of our findings is supported by the participation of different rehabilitation centers distributed over four German federal states allocated to two medium-sized towns and eight major cities. Therefore, the heterogeneity of different German regions with diverse conditions of labor markets was properly reflected. Moreover, external validity was reinforced by selecting regular rehabilitation centers instead of highly specialized university hospitals as treatment facilities. Conclusion
Partial replacement of standard exercise therapy by treatments with a stronger focus on job demands did not lead to improved work ability. A further dissemination of this specific aftercare program instead of conventional structured aftercare is not necessary. Improvement of aftercare probably needs a more basic change, such as employer participation and work modification.
Acknowledgements The study was funded by the German Pension Insurance Agency. Conflicts of interest
There are no conflicts of interest.
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Work-related rehabilitation aftercare for patients with musculoskeletal disorders: results of a randomized-controlled multicenter trial Sebastian Knappa, Juliane Briesta and Matthias Bethgeb There is evidence that rehabilitation with a multidisciplinary focus on work-related demands effectively improves work ability and quickens return to work in patients with musculoskeletal disorders. There could be benefits to the transfer of work-related components into rehabilitation aftercare. We examined the effectiveness of an intensified work-related rehabilitation aftercare program compared with standard intensified rehabilitation aftercare in Germany on work ability. We randomly assigned 307 patients with musculoskeletal disorders from 11 rehabilitation centers to an aftercare program with work-related functional capacity training, work-related psychosocial groups, social counseling, relaxation training and exercise therapy (intervention group), or the usual aftercare program consisting of only exercise therapy (control group). The 6-month follow-up questionnaire was completed by 78.5% of patients. There was no statistically relevant betweengroup difference in follow-up primary (work ability) and secondary outcomes (e.g. health-related quality of life, sick leave duration). Significant improvements were observed within both the intervention and the control groups. Severely disabled participants in the intervention group had better
Introduction In Western countries, access to rehabilitation services is an established opportunity within the social security scheme (Saltychev et al., 2011; Tengland, 2011; Bethge et al., 2012). Improvement of work ability, participation in working life, timely return to work, and prevention of disability pensions are major aims of these programs. To achieve these objectives, early interventions, workplace involvement, and multiprofessional treatment seem to be essential components (Carroll et al., 2010; Hoefsmit et al., 2012; Schaafsma et al., 2013). One important element of a return to work strategy, especially in patients with musculoskeletal disorders, is physical conditioning. This is supported by recent findings of a systematic review, which shows that intense physical exercise is beneficial in reducing time to return to work in patients with chronic and subacute back pain (Schaafsma et al., 2013). In Germany, this awareness is reflected by a new guideline for work-related medical rehabilitation (WMR) (Streibelt and Buschmann-Steinhage, 2011; Bethge et al., 2013). This guideline recommends WMR, especially for patients with repeated and long-term sick leave episodes and patients with poor self-reported return to work prognosis. WMR 0342-5282 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
physical functioning and shorter sick leave duration after 6 months compared with severely disabled patients in the control group. A partial replacement of standard exercise therapy by a more work-related therapy does not seem to improve work ability superiorly. Improved aftercare treatment may require a focus on employer participation and involvement within the actual work environment. International Journal of Rehabilitation Research 38:226–232 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. International Journal of Rehabilitation Research 2015, 38:226–232 Keywords: aftercare, back pain, musculoskeletal diseases, randomizedcontrolled trial, rehabilitation a
Department of Rehabilitation Medicine, Hannover Medical School, Hannover and Section Rehabilitation and Work, Institute of Social Medicine and Epidemiology, University of Lübeck, Lübeck, Germany b
Correspondence to Sebastian Knapp, MA, Department of Rehabilitation Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany Tel: + 49 89 289 24421; fax: + 49 89 289 24452; e-mail: [email protected] Received 6 February 2015 Accepted 7 April 2015
programs follow the principles of functional restoration (Gatchel and Mayer, 2008) and work hardening (Schaafsma et al., 2013). These programs generally consist of functional capacity evaluation (Isernhagen, 1992; Bieniek and Bethge, 2014), functional capacity training, work-related psychosocial groups, and intensified social counseling. Although the current guidelines do not cover precise recommendations for activities and follow-up treatments after the completion of a WMR program, it is indicated that a structured aftercare based on the principles of WMR could be useful for these patients. In Germany, aftercare programs are usually provided in outpatient rehabilitation centers and are limited only to exercise therapy [intensified rehabilitation aftercare (IRAC)]. Between 2008 and 2010, the number of completed aftercare programs increased from 98 000 to 150 000 (Deutsche Rentenversicherung, 2012). Approximately 90% of these services are implemented following musculoskeletal rehabilitation. A recent multicenter survey observed that aftercare participants with severe limitations in workrelated functioning reported strong interest in additional work-related functional capacity training, work-related psychosocial groups, and social counseling (Briest and DOI: 10.1097/MRR.0000000000000117
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Work-related rehabilitation aftercare Knapp et al. 227
Bethge, 2013). Such treatments are currently not a regular part of conventional aftercare programs, which means that problems during the return to work process may not be responded to in a timely and professional manner. For example, exercise schedules need to be promptly adapted to discrepancies between job demands and individual physical capacity during the return to work process. To improve the effect of rehabilitation aftercare, we developed a novel program [intensified work-related rehabilitation aftercare (IWORAC)] that applies the already existing WMR principles to aftercare rehabilitation. The current study examines the effects of IWORAC on work ability and further secondary outcomes in comparison with standard IRAC in patients with musculoskeletal disorders.
work-related functional capacity training, work-related psychosocial groups, social counseling, and relaxation training. At least three of these four interventions were selected by the rehabilitation team and the patient according to the personal needs of the patient. The minimum duration of the work-related interventions of the IWORAC ranged from 7 to 12 h, that is 20–30% of the usual IRAC program. The new work-related treatments replaced the corresponding extent of exercise therapy that is usually provided in IRAC. Beyond the work-related interventions, IWORAC treatment followed the same program of exercise therapy as IRAC. IWORAC elements were tested and practiced during a previous implementation phase in all centers. Work-related functional capacity training
Materials and methods Study design
The effects of IWORAC were compared with those of usual IRAC in a randomized-controlled trial. Participants of the intervention group (IG) received IWORAC, which is explained in detail below. Participants of the control group (CG) were assigned to IRAC. Data collection was performed using questionnaires at the beginning of the aftercare program and 6 months later. The study protocol was approved by the ethics committee of the Hannover Medical School (ethics committee nr.: 6073) and data protection officers of the involved pension insurance agencies. The study is registered in the German Clinical Trials Register (DRKS00003360).
The work-related functional capacity training was supervised by physical therapists trained to perform functional capacity evaluations (Isernhagen, 1992; Bieniek and Bethge, 2014). Examples of exercises considered typical work-related physical tasks were lifting, carrying, or working overhead. If functional capacity training was not already performed during rehabilitation, the patients received an initial one-to-one briefing (60 min). During this initial session, functional capacity was individually assessed and compared with the job demands to define an appropriate training schedule. The training was performed in small groups of four to six participants during 5–12 sessions of 60 min each. The duration, intensity, and levels of difficulty were increased continuously from session to session (Staal et al., 2004).
Inclusion criteria
The patients included ranged in age from 18 to 65 years. Rehabilitation aftercare was approved because of one of the following ICD-10 diagnoses: M16, M17, M50, M51, M53, M54, M75, Z96.6, Z96.8, or Z98.8. All participants were employed and fulfilled at least one of the following criteria: (a) sick leave duration of at least 3 months within the last year, (b) still on sick leave at the beginning of the aftercare phase, or (c) poor subjective return to work prognosis according to the Wuerzburger Screening (Lukasczik et al., 2011). Control group
The traditional IRAC consists of 24 90-min sessions of strength and endurance training. Training sessions are performed in groups of not more than 15 patients. Patients start the aftercare program after discharge from previous rehabilitation and complete the program within 3 months. Intervention group
IWORAC was performed at the same frequency and duration as IRAC (24 sessions for 90 min each within 3 months). Specifically, work demands and work ability were targeted by adding established work-related rehabilitation modules (Bethge et al., 2011) to the program. These modules include
Work-related psychosocial groups
The patients learned methods and strategies to cope with relevant work-related and daily life problems. The psychosocial sessions were held in small groups of four to 10 participants. If the rehabilitation team and the patient decided to include a work-related psychosocial treatment, they chose at least two of the following six modules, which consisted of two 60-min sessions each. (1) Fit at work: Using an established questionnaire on work behavior and work-related attitudes, the patients gained knowledge of their individual work behavior. In addition, coping strategies for different behavior patterns were developed (Voltmer et al., 2011). (2) Conflict management: Patients discussed the different levels of communication (e.g. factual content, selfdisclosure, appeal, relation). Moreover, they learned to distinguish between secure, insecure, and aggressive behavior in conflict situations (Kaluza, 2007). (3) Emergency strategies: Strategies for the management of acute stress situations were taught in this module. The patients gained knowledge of their own typical stress symptoms (Kaluza, 2007). (4) Social support: The patients learned different patterns and mechanisms of relationships and learned to
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228 International Journal of Rehabilitation Research 2015, Vol 38 No 3
analyze relationships. In addition, the patients analyzed their own social network and developed ways to change unfavorable relationships (Heitzmann et al., 2008). (5) Work–life balance: The patients gained knowledge of work–life balance. Furthermore, they became aware of the roles that they assumed in their own life and learned to distinguish important from unimportant roles (Heitzmann et al., 2008). (6) Time management: Patients learned systematic strategies to plan daily and weekly activities. They also learned to rank the importance and urgency of tasks and to establish priorities accordingly (Kaluza, 2007). A manual that described contents and performance was developed. The trainers were prepared to conduct these modules in train-the-trainer sessions. Social counseling
Social counseling was conducted in a one-on-one session of at least 15 min. Its timing in the aftercare process depended on the topics to be clarified. Specifically, the social counseling session explored the status of progression of return to work and qualification measures initiated in the previous rehabilitation phase. Relaxation training
The patients refreshed the skills that they had learned during their initial rehabilitation and received support for transferring these techniques into daily life, including abbreviated techniques that could be performed easily at the workplace. The relaxation training was conducted for 6–12 sessions of 30 min each in groups of four to 10 participants. Outcomes Primary outcome
Work ability was measured by the Work Ability Index (WAI) (Ilmarinen, 2007). The WAI assesses the degree to which workers consider their state of health as adequate to cope with the demands of their job. The questionnaire comprises the following subscores: (1) current work ability compared with lifetime best, (2) work ability in relation to the demands of the job, (3) number of current diseases diagnoses, (4) estimated work impairment because of disease, (5) amount of sick leave during the past year, (6) self-prognosis of work ability 2 years into the future, and (7) mental resources. Item scores were summed to yield a total score. The total score ranges from 7 to 49, with higher scores indicating better work ability. Secondary outcomes
Health-related quality of life was measured using the eight subscales of the Short-Form Health Survey (SF-36) (Ware and Sherbourne, 1992). Depressive symptoms
were assessed using the nine-item depression module from the Patient Health Questionnaire (PHQ-9) (Kroenke et al., 2001). Pain intensity was measured by an average score of three 11-point numerical scales rating the current, strongest, and average intensity of pain (Jensen et al., 1999). The cumulated number of weeks of sick leave in the last 3 months was calculated to determine the level of participation in working life. Further variables
Sociodemographic information was assessed to characterize the recruited participants. Diagnoses and treatments during the programs were extracted from the physician’s discharge report. Randomization
Because of the successive recruitment of patients, randomization was performed in blocks with permuted block sizes to achieve maximal balance between both groups. Numerous brief lists (with block size of 2, 4 or 6) were generated using the STATA procedure ‘ralloc’ and then connected randomly to create randomization lists. These randomization lists were created for each rehabilitation facility. For the allocation, nontransparent, closed randomization envelopes were produced. Envelopes were marked by a unique study identification number to ensure that the study participants and envelopes were matched precisely. An enclosed document showed information on allocation. Sample size estimation
Sample size estimation was performed to confirm a standardized mean difference (SMD) of 0.3 (two-sided error probability: 5%; power: 90%). Assuming a correlation of r = 0.4 between the baseline and the follow-up measurement, a sample size of 396 participants for our analysis of the primary outcome was targeted. Statistical analyses
Sample characteristics and treatment precision (adherence to the treatment protocol) were analyzed by descriptive statistics. To quantify differences in treatment intensity between rehabilitation centers, intracluster correlation coefficients were calculated. To calculate these coefficients, the variance of a measurement is decomposed in a variance component that is related to the center and a variance component that is related to individual characteristics (Kerry and Bland, 1998). The intracluster correlation indicates the part of the variance that is explained by the center characteristics. If the treatment intensity is independent of the center, this coefficient should approach zero. Treatment effects on the primary and secondary outcomes were analyzed by generalized linear regression models that included a random intercept to account for the dependency of measures within the same rehabilitation center. Baseline scores of the dependent variable were included as covariates
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Work-related rehabilitation aftercare Knapp et al. 229
(Vickers and Altman, 2001). All participants were included and data were analyzed on an intention-to-treat basis. SMDs were calculated by dividing the regression coefficient of the treatment effect by the pooled SD of the follow-up measurements (Lipsey and Wilson, 2001). SMDs were interpreted according to Cohen’s effect size conventions (SMD ≥ 0.2: small; SMD ≥ 0.5: medium; SMD ≥ 0.8: large) (Lipsey and Wilson, 2001). To calculate intragroup effects to characterize the change between measurements, the mean differences of followup and baseline measurements were divided by the corresponding baseline SD [standardized effect size (SES)] (Kazis et al., 1989). In addition, treatment effect moderators were analyzed to clarify whether certain subgroups benefit more or less than others. In particular, we analyzed whether effects on secondary outcomes (e.g. physical functioning and sick leave duration) depended on baseline work ability. The modeling of the moderator effect was performed by a multiplicative interaction term of the treatment indicator and the z-standardized baseline WAI (Smeets et al., 2009). Treatment effects were calculated for low WAI scores (average WAI score − 1 SD), the average WAI score, and high WAI scores (average WAI score + 1 SD). All analyses were carried out using STATA, version 12 (Stata Corp LP, College Station, Texas, USA).
Results Recruitment and sample size
Patients were recruited between February 2012 and February 2013. In total, 307 patients agreed to participate in the study and were assigned to IG (n = 157) or CG (n = 150) (Fig. 1). The 11 rehabilitation centers recruited, on average, 28 patients (range: 10–44). The 6-month follow-up questionnaire was completed by 241 (78.5%) patients. A comparison between follow-up participants and nonparticipants showed no significant differences. The follow-up participants were slightly older and reported less pain. The total treatment duration during aftercare was similar (IG vs. CG: 34.9 vs. 31.4 h). Sample characteristics at baseline are summarized in Table 1. Approximately half of the patients were women (54.7%). The average age was 46.5 years (SD = 10.2). Around two-thirds of the aftercare interventions were approved because of ICD-10 diagnoses M50 to M54. About 70.1% of the patients were employed full time. At the beginning of the aftercare, three-fourths of the patients were still on sick leave. Sick leave duration before rehabilitation was, on average, 9.4 weeks (SD = 4.7). Two-thirds of the patients had very low WAI scores (7–27 points), indicating poor work ability. Both groups were similar in terms of the variables assessed.
Treatment credibility
On average, about 9 h (562 min) of the treatments of the IG were work-related interventions. This corresponded to a quarter of the total treatment dose of the aftercare program and was in accordance to the defined minimum amount of work-related modules as described in the treatment protocol (7–12 h). However, there was marked variance between the 11 cooperating facilities. Although two centers performed more than 17 h of specific workrelated interventions, in two other centers, less than 2 h of specific work-related interventions were completed. In four centers, the average treatment dose provided was close to the overall mean. Intracluster correlation coefficients for single treatment modules ranged from 0.33 to 0.49, indicating that ∼ 30–50% of the differences in the treatment dose provided were explained by the centers. Explanation by center was strongest for the treatment dose of workrelated psychosocial groups. The intracluster correlation coefficient for the overall work-related treatment dose was 0.43 [95% confidence interval (CI): 0.21–0.67]. Primary outcome
There was no statistically relevant difference in follow-up work ability between IG and CG in the intention-to-treat analysis (Table 2). Although no significant betweengroup differences could be identified, work ability improved with SES = 0.46 (95% CI: 0.29–0.62) considerably in the IG. Secondary outcomes
There were also no significant between-group differences for the secondary outcomes (Table 2). Patients of the IG showed reduced sick leave duration (SES = 1.38; 95% CI: 1.14–1.62) and better physical quality of life compared with baseline, for example physical role (SES = 1.11; 95% CI: 0.84–1.38). Moderator analysis
Analyses of the WAI as an effect modifier showed an additional benefit for IG patients with low WAI scores (Table 3). With increasing baseline limitations, that is lower WAI scores, the results of both groups differed stronger. Patients of the IG with low WAI scores showed a significant increase in their physical functioning (b = 7.58; 95% CI: 0.68–14.49) and a decrease in their sick leave duration (b = − 2.08; 95% CI: − 3.38 to − 0.33) compared with similar patients in the CG.
Discussion Patients attending IWORAC neither had better work ability than controls nor showed greater improvement on any of the secondary outcomes. Only very severely limited patients benefited from attending IWORAC compared with similar controls from IRAC.
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230 International Journal of Rehabilitation Research 2015, Vol 38 No 3
Fig. 1
Randomized (n = 307)
Patients assigned to IRAC
Patients assigned to IWORAC
(n = 150)
(n = 157)
Analyzed after 6 months
Analyzed after 6 months
(n = 120)
(n = 121)
Flow of patients. IRAC, intensified rehabilitation aftercare; IWORAC, intensified work-related rehabilitation aftercare.
Table 1
Sample characteristics at baseline IRAC
Sex: female (%) Age in years [mean (SD)] Diagnosis: M50-M54 (%) Full-time employed (%) Still on sick leave (%) Sick leave duration (past 3 months) [mean (SD)] Work Ability Index [mean (SD)] Good/very good work ability (%) (37–49 points) Moderate work ability (%) (28–36 points) Poor work ability (%) (7–27 points) Physical functioning (SF-36) [mean (SD)] Physical role (SF-36) [mean (SD)] Bodily pain (SF-36) [mean (SD)] General health (SF-36) [mean (SD)] Vitality (SF-36) [mean (SD)] Social functioning (SF-36) [mean (SD)] Emotional role (SF-36) [mean (SD)] Mental health (SF-36) [mean (SD)] Depressive symptoms (PHQ-9) [mean (SD)] Pain intensity [mean (SD)]
IWORAC
Total
n
Mean (SD) or %
n
Mean (SD) or %
n
Mean (SD) or %
150 150 150 147 149 137 143
52.7 46.9 (10.1) 57.3 74.1 77.9 9.3 (4.8) 24.8 (7.4) 4.9 31.5 63.6 54.7 (22.1) 13.5 (27.4) 33.1 (19.5) 53.4 (18.1) 44.3 (19.6) 58.6 (27.8) 53.0 (47.3) 61.0 (21.8) 7.5 (5.3) 5.8 (1.8)
157 157 157 154 157 146 140
56.7 46.9 (10.1) 64.3 66.2 79.0 9.5 (4.6) 24.8 (7.8) 7.1 31.4 61.4 55.2 (21.4) 12.2 (25.4) 33.1 (15.8) 51.6 (18.6) 43.2 (19.2) 60.2 (25.8) 54.3 (45.0) 60.2 (20.2) 7.7 (5.7) 5.7 (1.8)
307 307 307 301 306 283 283
54.7 46.5 (10.2) 60.9 70.1 78.4 9.4 (4.7) 24.8 (7.6) 6.1 31.4 62.5 54.9 (21.7) 12.8 (26.4) 33.1 (17.7) 52.5 (18.3) 43.7 (19.4) 59.4 (26.7) 53.7 (46.1) 60.6 (21.0) 7.6 (5.5) 5.7 (1.8)
149 149 150 150 150 150 149 150 150 148
157 154 157 154 157 157 151 157 154 153
306 303 307 304 307 307 300 307 304 301
IRAC, intensified rehabilitation aftercare; IWORAC, intensified work-related rehabilitation aftercare; PHQ, Patient Health Questionnaire; SF-36, 36-Item Short-Form Health Survey.
Intense physical conditioning programs have shown benefits in subacute and chronic pain patients in reducing time to return to work compared with usual care (Schaafsma et al., 2013). However, it is debatable whether treatment dose or content leads to reduced return to work time. Although several reviews indicate that a focus on work-related content can improve work ability and return to work (Tveito et al., 2004; Norlund et al., 2009; Carroll et al., 2010; Odeen et al., 2013; Schaafsma et al., 2013), most of the studies included compared comprehensive treatments against usual care. Consequently, dose and content are interrelated, and therefore, are very difficult to interpret independently.
Kool et al. (2005) and Kool et al. (2007) showed that a more function-centered rehabilitation program might be more appropriate than a pain-centered program in supporting return to work. However, function centering is a common characteristic of modern exercise treatment schemes and not solely a merit of work-related functional capacity training. This might explain why the stronger focus on work-related demands was not associated with improved work ability in our study. Nevertheless, the most apparent weakness of the established IWORAC program in comparison with other work-related rehabilitation programs that have successfully reduced the time to return to work (Loisel et al., 1997; Lambeek et al., 2010) is
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Work-related rehabilitation aftercare Knapp et al. 231
Table 2
Primary and secondary outcomes at the 6-month follow-up IG n
Work Ability Index Sick leave duration (past 3 months) Physical functioning (SF-36) Physical role (SF-36) Bodily pain (SF-36) General health (SF-36) Mental health (SF-36) Vitality (SF-36) Social functioning (SF-36) Emotional role (SF-36) Depressive symptoms (PHQ-9) Pain intensity
99 110 121 119 121 118 121 121 121 115 118 117
CG
EMM (SE) 29.0 2.6 63.7 41.0 44.3 54.0 63.3 48.2 67.3 64.1 7.3 4.9
(0.6) (0.5) (1.9) (3.6) (1.8) (1.4) (1.7) (1.8) (2.1) (3.8) (0.4) (0.2)
n 113 106 118 118 119 119 119 119 119 119 120 117
EMM (SE) 28.9 3.2 60.7 39.0 44.1 53.2 63.5 46.7 67.4 62.2 7.4 4.8
(0.6) (0.5) (1.9) (3.6) (1.8) (1.4) (1.7) (1.8) (2.1) (3.7) (0.4) (0.2)
b
95% CI
P
SMD
0.09 − 0.62 3.00 2.00 0.16 0.72 − 0.13 1.53 − 0.06 1.91 − 0.09 0.11
− 1.63 to 1.80 − 1.98 to 0.74 − 1.93 to 7.93 − 7.87 to 11.87 − 4.81 to 5.14 − 3.02 to 4.46 − 4.37 to 4.12 − 2.92 to 5.97 − 5.96 to 5.85 − 7.27 to 11.09 − 1.16 to 0.98 − 0.39 to 0.61
0.921 0.371 0.234 0.692 0.948 0.706 0.954 0.501 0.985 0.683 0.871 0.672
0.01 0.12a 0.12 0.05 0.01 0.04 − 0.01 0.07 0.00 0.04 0.02a − 0.04a
b, unstandardized regression coefficient; CG, control group; CI, confidence interval; EMM, estimated marginal mean; IG, intervention group; PHQ, Patient Health Questionnaire; SF-36, 36-Item Short-Form Health Survey; SMD, standardized mean difference. a Regression coefficient was multiplied by − 1; therefore, a positive standardized difference indicates a superior result for the IG.
Table 3
Comparison of IG versus CG by low, average, and high baseline WAI scores SF-36 physical functioning (n = 226)
Low WAI Average WAI High WAI
Sick leave duration (n = 205)
b
95% CI
P
b
95% CI
P
7.58 3.11 − 1.37
0.68–14.49 − 1.76 to 7.98 − 8.28 to 5.55
0.031 0.211 0.699
− 2.08 − 0.90 0.29
− 3.83 to − 0.33 − 2.13 to 0.34 − 1.47 to 2.04
0.020 0.155 0.750
Combined estimates for low WAI scores (average WAI score − 1 SD), average WAI score, and high WAI scores of the first measurement (average WAI score +1 SD) from regression models with multiplicative interaction of baseline WAI and treatment indicator. b, unstandardized regression coefficient; CG, control group; CI, confidence interval; IG, intervention group; SF-36, 36-Item Short-Form Health Survey; WAI, Work Ability Index.
that a stronger focus on job demands was realized without actual workplace involvement. Involving the actual workplace environment, by including meetings with supervisors, workplace visits, or cooperation with an occupational physician at the workplace or a case manager of the insurance agency, who coordinates the process of return to work, may increase the effectiveness of these programs. Recent studies confirmed that such developments are also feasible within the German rehabilitation setting (Schwarze et al., 2013). Currently, different aftercare strategies are tested and implemented in Germany. Structured aftercare in Germany, including IRAC and IWORAC, are compensatory strategies. This is because primary rehabilitation programs are too short and their treatment doses are too low to affect functional and work ability outcomes (Guzman et al., 2001). Aftercare attempts to compensate for this lack of appropriate treatment dose by offering additional exercise treatments. In the future, recognizing the effects of active workplace involvement could help to improve the effects of structured aftercare programs. Most importantly, work participation is not only determined by the individual’s functional capacity but a range of environmental factors (Hayden et al., 2009; Van den Berg et al., 2009). As well as the cooperation of rehabilitation facilities and social security agencies, the continuous involvement of employers might be required so that all stakeholders follow a mutually shared rehabilitation strategy
(Lambeek et al., 2010). As aftercare programs are usually performed in outpatient centers that are close to the homes and workplaces of participants, networks of rehabilitation facilities and employers are not hindered by long distances so that regular meetings and workplace visits are feasible. The results of the current study must be interpreted within the context of the following limitations. Primarily, despite an implementation phase before this study, adherence to the treatment protocol was poor in some centers. Second, the targeted sample size was not reached as recruitment was rather slow and financial support was restricted. However, an inspection of the effect sizes provides no hint that statistical significance failed because of a very small sample size. Third, the follow-up period of our analyses was rather short. A longer time frame might be needed to establish the potential benefit of rehabilitation programs with a stronger focus on work-related functional capacity than compared with other exercise schemes as a recent metaanalysis showed that between-group differences in workrelated outcomes increase in later follow-up measurements (Schaafsma et al., 2013). A 12-month follow-up will therefore examine whether the stronger focus on workrelated capacities is superior in the long term. These limitations are balanced by the following strengths. The internal and external validity of this study is strengthened by its randomized-controlled multicenter
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232 International Journal of Rehabilitation Research 2015, Vol 38 No 3
design. Randomization of patients prevented selection bias and yielded comparable study groups. Generalizability of our findings is supported by the participation of different rehabilitation centers distributed over four German federal states allocated to two medium-sized towns and eight major cities. Therefore, the heterogeneity of different German regions with diverse conditions of labor markets was properly reflected. Moreover, external validity was reinforced by selecting regular rehabilitation centers instead of highly specialized university hospitals as treatment facilities. Conclusion
Partial replacement of standard exercise therapy by treatments with a stronger focus on job demands did not lead to improved work ability. A further dissemination of this specific aftercare program instead of conventional structured aftercare is not necessary. Improvement of aftercare probably needs a more basic change, such as employer participation and work modification.
Acknowledgements The study was funded by the German Pension Insurance Agency. Conflicts of interest
There are no conflicts of interest.
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