Vol. 21, No. 5 Printed in Great Britain
International Journal of Epidemiology © International Epktemiotogical Association 1992
Epidemiology of Prostatic Disorders in the City of Barcelona ESTEVE FERNANDEZ. MIQUEL PORTA. JORDI ALONSO AND JOSEP M ANTO
ing to the Jewish religion.8 Twenty per cent of 318 presurgical BPH patients studied by Fowler9 rated their health as fair or poor, and significant quality of life problems have been associated with BPH.10 These figures all but underline the scarcity of epidemiological information currently available on the health status of men suffering PD. The primary objective of this analysis was to estimate the prevalence of PD in the city of Barcelona, and to analyse sociodemographic characteristics, selfperceived health, use of health services and lifestyle factors of men reporting PD.
While the burden disorders of the prostate inflict on elderly males is significant1"16 and the treatment of benign prostatic hyperplasia (BPH) is currently the object of heated controversy,17"22 little is known about the epidemiological characteristics of such disorders. Based on five autopsy studies Berry et al? estimated the overall prevalence of histological BPH to increase from 8% among 40 year old men to over 70"% in men over 70. Similar prevalence figures of clinically diagnosed BPH have been reported in prospective longitudinal studies6 but higher figures may be found when strict diagnostic criteria are applied.15 The incidence of clinical BPH found in the Normative Aging Study8 ranged between 31.3 per 1000 person-years (males aged 50-59 years) and 59.2 per 1000 personyears (males aged 70-87 years). Prevalence of BPH appears to be somewhat higher among Blacks and Jewish people. Yet, the relationship with other factors, such as smoking, coffee drinking, or marital status, is not well-established. '•3-s-13 An increased rate of surgery for prostatic disorders (PD) was found for subjects in low socioeconomic groups, nonsmokers and men belong-
MATERIAL AND METHODS The study is based on data from the 1986 Barcelona Health Interview Survey (BHIS). A detailed description of methods has been published elsewhere.23 In summary, BHIS is a cross-sectional study of a random sample of the noninstitutionalized population of the city of Barcelona, based on the 1981 Municipal Census (revised in 1985). The sample was stratified by municipal district and by family size. All individuals were selected in every household (sample unit). Detailed rules were established to address nonresponders and substitutions. Sixteen per cent of households were replaced and family nonresponse rate was n.5°?o. The final sample included 6894 individuals: 3231 men and 3663 women. The greatest error for variables with a frequency about 50% was ± 1 % , with an a error of
Dcpartament d'EpidemiologU i Salut Publica, Institut Municipal d'lnvestigacid Medica, Universiuu Autbnoma de Barcelona, Passeig Maritim 25-29, E-O8OO3 Barcelona, Spain. Reprint requests: Dr Miquel Porta. Presented to the 1991 German and English Language Regional European Meeting of the International Epidemiological Association (IEA), Basel, Switzerland, 29-31 August 1991. Book of abstracts: 142.
959
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Fernandez E (Departament d'Epidemiologia i Salut Publica, Insthut Municipal d'Investigaci6 Medica, Universrtat Autbnoma de Barcelona, Passeig Marftim 25-29, E-08003 Barcelona, Spain), Porta M, Alonso J and Ant6 J M. Epidemiology of prostatic disorders in the city of Barcelona. Internationa/ Journal of Epidemiology 1992; 21: 959-965 Although disorders of the prostate are among the most prevalent problems in elderty males, little is known about their epidemiological characteristics. The 1986 Barcelona Health Interview Survey (BHIS), a cross-sectional study of a random sample of the noninstitutionalLzed population of the city, was used to estimate the prevalence of prostatic disorders (PD) and to analyse sociodemographic characteristics, self-perceived health, and use of health services among males reporting PD. Ninety-eight out of 1218 males over 45 years old (8%) reported having PD, the prevalence increasing substantially with age. A pattern of increasing prevalence with decreasing occupational class was found. As compared to subjects not reporting PD, individuals reporting PD reported slightly more restricted activity days (prevalence odds ratio [POR] = 1.28; 95% confidence interval [Cl] : 0.52-2.80), more chronic disorders (POR = 4.75; 95% Cl: 2.04-13.53), and worse self-perceived health (POR = 1.55; 95% Cl: 0.92-2.58). Medical visits and hospitalizations were also higher in the prostatic group (P < 0.05). Men reporting PD appear to constitute a subgroup with increased morbidity and health services use.
960
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
kappa statistics27 were computed for the comparison between the answer in 1986 and the 1991 telephone survey. Procedures were implemented under SPSS-X, SAS, and EGRET. The significance level was established at 5% and all tests are two-tailed. RESULTS The overall prevalence of self-reported PD in all males over 45 years was 8%, in males 45-64 years it was 4.6"%, and in those aged 65 or over about 16% (Table 1). Prevalence figures were similar across years of education. As for occupational class, a pattern of increasing prevalence with decreasing class was found. TABLE 1 Prevalence of self-reported prostatle disorder! among males aged >*5 years by age groups and selected sociodemographic characteristics, 1986 Barcelona Health Interview Survey
Prevalence ( f t )
No.
95ft CI*
8.05 4.6 10.1 24.4 27.8
98/1218 39/843 24/238 29/119 5/18
8.0-8.1 3.6-5.9 6.6-14.4 16.7-32.1 7.(M8.4
15.7
59/375
12.4-19.4
Years of education >16 years 9-15 years 1-8 years None
7.5 6.3 9.7 5.1
9/120 21/331 63/647 5/98
3.5-13.3 4.4-9.0 9.7-9.9 1.7-11.1
Occupational class I—II III IV-V VI
5.3 7.8 8.9 10.9
13/243 25/322 50/561 10/92
2.9-8.7 5.4-10.8 6.9-11.2 5.4-18.0
Occupational status Retired Economically active Unemployed Other
15.4 2.7 6.7 12.2
69/449 17/630 6/90 6/49
15.3-15.5 1.7-4.2 2.5-13.2 4.6-24.0
Age A l l ( > 4 5 years) 45-64 yean 65-74 years 75-84 years >85 years >65 years
* 95 per cent confidence interval.
Sociodemographic characteristics of the prostatic and control groups are shown in Table 2. As expected, mean age was greater in the prostatic group, with 4O°7o of subjects being under 65 years, as compared to 72% in the control group (P < 0.001). There were no statistically significant differences in marital status nor in years of education. Although no statistically significant association was found between occupational class and the presence of PD, a greater proportion of men in classes I—II exists in the control group (Table 2).
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
5%. Family members or the family head were directly interviewed at home by trained non-health professionals using a precoded questionnaire that requested information on sociodemographic characteristics, selfperceived health, health services use, and lifestyle. In order to assess the overall prevalence of chronic conditions, the questionnaire also included a list of 34 chronic conditions, one of which was 'disorders of the prostate'. Each of these conditions was specifically read to the interviewee. In the present analysis all males aged 45 years or over reporting PD were identified (case group, n = 98). All males in the same age range not reporting PD were selected as controls (n = 1120). While the age cutoff point allowed some control for potential bias induced by age, further adjustments were carried out through stratified analysis and unconditional logistic regression. Control for comorbidity was carried out in two ways: a) in stratified analyses, through the variable 'chronic conditions' (presence/absence of any chronic condition other than PD); and b) in logistic regression, by using the exact number of chronic conditions (range: 0- ^ 8). In order to assess the accuracy of data concerning PD obtained through the personal interview in 1986, and to estimate the malignant or benign status of reported PD, a telephone survey was conducted between April and September 1991. A random sample stratified by study group and age (n = 60) was selected from the 1218 men included in the study. If after six phone calls without answer evidence was obtained of death or of moving (without possibility of identification), the individual was replaced. The total number of individuals successfully interviewed was 40. All telephone calls were made by the same interviewer (EF), who was blind to the interviewee's answer in 1986. Questions were asked about current or past history of PD. If the answer was affirmative, the time span of the disease was sought, and this was later compared with the answer provided in 1986. On the basis of the subject's description of treatment received, an estimate of the nature of PD was made (benign, malignant or inconclusive). Normality was assessed with the KolmogorovSmirnov test. The t-test and the Mann Whitney U test were used for continuous variables. In contingency tables, when 20% or over of cells had expected counts less than five, Fisher's exact test was used. Confidence intervals for proportions were computed by the exact method.24 In stratified analyses the logit estimator of the prevalence odds ratio (POR)25 was used. Further adjustments were conducted by unconditional logistic regression.26 The overall proportion of agreement and
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA TABLE 2 Sociodemographic differences between the prostatic and the control group
Control group (No. - 1120)
68.7(10.1) 47-91
59.4(9.8) 45-97
0.05). The mean number of bed days per person-year (bed days/ person-year) was 3.4 in the prostatic group and 5.9 in the control group (P = 0.81); among subjects 75 years or over the prostatic group showed a mean of 7.6 bed days/person-year versus 2.0 in the control group (P = 0.42). Individuals reporting PD also reported more restricted activity days (PORa = 1.57, P > 0.05). In order to control for comorbidity, stratification for chronic conditions (presence/absence of any chronic condition other than PD) was next carried out. The age and comorbidity adjusted prevalence odds ratio JPORac] was 0.91 for bed days and 1.28 for restricted activity days (Table 3). The mean of restricted activity days/person-year was slightly greater in the prostatic group (P = 0.10), as was the rate of chronic disorders. Overall, the proportion of men with chronic restric-
tion in their usual activities was greater in the prostatic group (PORa = 1.44, 95% CI : 0.74-2.79). The proportion with any chronic disorder (excluding PD) was greater in the prostatic group (PORa = 4.75, P < 0.05). The most common chronic disorders in the two groups were arthrosis, circulation disorders, high blood pressure, bronchitis/asthma and deafness; all were more prevalent in the prostatic group (P < 0.05 in all cases). Heart disorders, haemorrhoids, hernia, kidney stones, stroke and cataracts were also more commonly reported in the prostatic group (P < 0.05). Self-perceived health was worse in the prostatic group (PORa = 1.76, P < 0.05) (Table 3). Whereas the association becomes statistically nonsignificant when stratifying for comorbidity and age, a 55% excess risk is still apparent (P = 0.101). Health Services Utilization Over 90% of subjects in the two groups were insured under the Spanish National Health System (SNHS). The proportion reporting any outpatient medical visit in the last two weeks before interview was greater in the prostatic group (PORa = 2.40, P < 0.05) (Table 4). So it was for the last 12 months (PORa = 3.45, 95% CI: 1.69-4.91). Prostatic patients were still twice as likely to report an outpatient medical visit than controls after stratifying for the presence of chronic conditions. The mean number of outpatient medical visits/ person-year was greater in the prostatic group (P < 0.001). Main reasons for medical visits in the prostatic group were infectious diseases (21.2% of reported medical visits), skin diseases (21.2%), diseases of the genitourinary system (15.2%) and circulatory system (15.2%); and, in the control group, disorders of the respiratory system (18.1%), circulatory system (14.1%), infectious diseases (12.4%) and skin diseases (12.4%). A lower proportion of men in the control group reported medical visits due to diseases of the genitourinary system (3.4%; P = 0.02). Importantly, when diseases of the genitourinary system were excluded, both the proportion of subjects reporting an outpatient medical visit (PORa = 2.05, 95% CI : 1.21-3.42; PORac = 1.70, 95% CI : 0.99-2.86) and the mean number of outpatient medical visits/person-year (P < 0.001) remained greater in the prostatic group. The SNHS was the main provider of medical care (67.6% in the prostatic group and 72.7% in the control group), and the most frequent setting of the visit was a general practice office (61.8% and 63.7%, respectively). More subjects in the prostatic group reported a hospitalization in the last 12 months before interview (PORac = 2.14, P < 0.05) (Table 4). The number of
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Projutic group (No. - 9 8 )
961
962
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY TABLE 3 Association between seif-reported prostatic disorders and perceived health. Stratified analysis
Age (years) 45-64 65-74 >75
AU
(4) (40)
4.1 3.5
5.1 3.1
— 5.9 5.7 2.9
(10) (66)
10.2 5.9
7.7 5.0
8.0 14.7 9.5 5.9
-
20.5 12.7
4.0 11.1
17.7 41.4 18.3 13.1
(90) (802)
93.7 71.9
89.7 68.2
91.7 100.0 81.6 81.2
—
441 165
415 148
396 451 205 227
(35) (283)
42.7 28.6
51.5 27.3
36.4 30.8
Individuals having had a bed day (ft)* Prostatic group Control group PORa (95ft CO = 1.08 (0.27-3.21) PORac = 0.91 (0.22-2.71) Individuals with restricted activity days (ft)* Prostatic group Control group PORa = 1.57 (0.68-3.33) PORac = 1.28(0.52-2.80) Number of restricted activity days PY Prostatic group Control group Individuals with a chronic disorder (ft) b Prostatic group Control group PORa =» 4.75 (2.04-13.53) Rate of chronic disorders0 Prostatic group Control group Self-perceived health evaluation*1 Prostatic group Control group PORa = 1.76(1.06-2.89) PORac = 1.55 (0.92-2.58)
37.0 34.1
* During last two weeks before interview. Other than prostatic disorders. c Per 100 individuals. Per cent with 'poor' self-perceived health. PORa: age-adjusted prevalence odds ratio. PORac: age and comorbidity adjusted prevalence odds ratio. PY: per person-year.
hospitalizations per 1000 person-years was greater in the prostatic group, too. The main reason for hospitalization was circulation disorders in both groups. As with outpatient medical visits, hospitalizations remained greater in the prostatic group after excluding diseases of the genitourinary system {P < 0.05). Lifestyle variables were also analysed and no major differences were found between the two groups in terms of physical activity, sleep patterns and smoking habits. The proportion of individuals attempting to lose weight was greater in the prostatic group (P < 0.05). Multivariate Logistic Regression Analysis A multivariate analysis through unconditional logistic regression was next carried out to assess the relation-
ship between reporting PD and self-perceived health controlling for other relevant variables. As shown in Table 5 (model A) variables associated with reporting 'poor' (poor, bad or very bad) health were: 1) belonging to a low occupational class, 2) having had a restricted activity day, and 3) reporting a chronic condition (other than 'disorder of the prostate'). Specifically, data show that when adjusting for age, occupational class, restricted activity and chronic conditions, prostatic subjects still had an excess risk of reporting poor health of about 25% (P = 0.42). The OR was 1.69 (P = 0.04) when the first two previous variables were considered, and it was 1.74 (P = 0.035) when the first three previous variables were adjusted for. Finally, the relationship between medical visits and PD was analysed. After controlling for age, occupational class, restricted activity days, chronic
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
(No.)
963
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA TABLE 4
Association between seff-reported prostatic disorders and use of health services. Stratified analysis
Age (years) 45-64 65-74 >75
All
(34) (184)
34.7 16.4
28.2 13.4
44.0 26.3
35.3 19.4
—
15.7 7.7
9.3 6.1
30.2 12.7
12.3 10.1
(15) (74)
15.5 6.7
5.1 5.7
20.8 11.3
23.5 5.0
214.2 74.1
102.5 59.7
280.0 131.4
294.1 67.9
Individuals reporting a medical visit (9i)* Prostatic group Control group PORa (95% CI) = 2.40 (1.42-3.81) PORac = 2.00(1.20-3.29) Number of medical visits PY Prostatic group Control group Individuals reporting any hospitalization (Vt)b Prostatic group Control group PORa » 2.23 (1.11-4.29) PORac = 2.14 (1.05^t.l4) Number of hospitalizations0 Prostatic group Control group ° During last two weeks before interview. During last 12 months before interview. c per 1000 persons per year. PY: per person-year. PORa: age-adjusted prevalence odds ratio. PORac: age and comorbidity adjusted prevalence odds ratio.
conditions, and self-perceived health (model B, Table 5) the association remained significant (OR = 1.80, P = 0.041). In simpler models including only some of the previous covariates, the OR ranged between 2.23 and 2.05 (P < 0.05 in all models). Telephone Survey As previously mentioned, through the telephone survey 40 subjects (20 from each study group) were successfully interviewed. The presence of PD in 1986 was confirmed in 19 out of 20 (95%) subjects. Onefifth (4/20) of individuals not reporting a PD in 1986 now did state they were affected in 1986. The overall observed concordance was 87.5*% and the Kappa index was 0.75. The proportion of suspected prostatic cancers inferred from the telephone survey among individuals reporting PD was 10%. DISCUSSION Few epidemiological studies on prostatic disorders have been conducted in Europe and North America and none have been conducted in Spain, except for a descriptive study on prostate cancer mortality.28 A bibliographic review through MEDLINE (period
01.1985-12.1991) and through the Spanish Medical Index (Indice Midico EspaHol) (period 01.1985-12.1990) yielded no other Spanish epidemiological publications on the topic. Other health interview surveys conducted in Spain did not publish prevalence figures for prostatic disorders.29"31 We estimated the prevalence of PD in Barcelona among males 65 years or over to be 15.7%, a figure substantially higher than the 6.4% estimate made by the 1989 National Health Interview Survey in the US for the same age group." The difference is likely to be due either to different perceptions of the disease among the two populations or to a real difference in prevalence of the disease, since both studies followed very similar methodologies for assessing chronic disorders such as PD. Jakobsen et al.u studied the enlargement of the prostate through transrectal ultrasound in 175 men aged 27-70 and found ultrasonic signs of adenoma in 46 prostates, i.e. a 26% prevalence. A study conducted in Scotland13 on 705 men yielded a prevalence for BPH of about 25% in males aged 40-79. In that study BPH was defined by transrectal ultrasonography, urinary symptomatology and peak flow rate; therefore, it is not surprising that the figure is higher than the prevalence rate of self-reported PD we estimated for
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
(No.)
964
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
TABLE 5 Logistic regression analysis of the relationship between prostatic disorders (PD) and self-perceived health (model A), and between PD and medical visits (model B)
Model B* OR (95% CI)
Self-perceived health11
Medical visits'1
Disorder of the prostate
1.25 (0.72-2.16)
1.80 (1.02-3.17)
Age
0.99(0.98-1.01)
1.03(1.01-1.05)
Occupational class IV-VC III I—II
1.00 0.77(0.54-1.09) 0.64(0.43-0.94)
1.00 1.29(0.86-1.93) 0.74(0.45-1.21)
4.38(2.35-8.17)
12.64(6.47-24.69)
1.47(1.34-1.61)
1.20(1.08-1.33)
Dependent variable Independent variables
Restricted activity11 Chronic conditions
1
Sdf-perceived healthb
1.76(1.19-2.60)
* Based on 1000 observations, 218 obiervations had missing values in dependent or independent variables. b Poor, bad or very bad = 1; Good or very good = 0. c Reference category. d Last two weeks before interview. c Range 0 to 8 ('disorder of the prostate' excluded).
the same age group (6.2*%). Well-defined criteria are undoubtedly needed in many instances, but it is unclear what relation such criteria may bear upon the demand or need for treatment;33 self-perception of disease is possibly a stronger predictor of the demand for care. In this study PD were assessed through a health interview survey, BHIS, which was mainly conducted to gather information about the general status of health in the community. Although health interview surveys are generally not aimed at obtaining prevalence figures for specific health problems,34'35 such surveys have certainly been used when other sources of information were lacking. 36~40 Therefore, although we deemed BHIS to be of value in order to procure a preliminary estimate of the prevalence of PD in our city, several aspects must be borne in mind. First, in this study, as in many health interview surveys, chronic conditions are self-reported by the individual, an objective diagnostic lacking. For common medical conditions (e.g. cataracts, diabetes, hypertension) good agreement has been found between self-reports and medical reports.35 Moreover, self-perception of health has been
ACKNOWLEDGEMENTS This work was partially funded by grants from Fondo de Investigaci6n Sanitaria (FIS 90/0488) and Merck, Sharp & Dohme. The authors are also grateful to Ana Ruig6mez and David J MacFarlane for scientific advice, and to Helena Martinez for technical assistance. REFERENCES 1
2
Barry M J. Epidemiology and natural history of benign prostatic hyperplasia. Urol Clin N Am 1990; 17: 495-507. Berry S, Coffey D, Walsh P, Ewing L. The development of human benign prostatic hyperplasia with age. J Urol 1984; 132: 474-77.
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Model A a OR (95ft Cl)
related to the individuals' need for health care41 and to mortality.42 Nevertheless, chronic conditions may be overreported43 or underreported.36'44 Our telephone survey yielded a good agreement (Kappa = 0.75), although it suggested some degree of underreporting may exist. Second, the questionnaire used by BHIS identified 'disorders of the prostate', which may include both benign and malignant processes. This source of misclassification was also assessed through the telephone survey and about 10% of PD were considered to be likely prostatic cancers. Whereas the prostatic group did report more chronic conditions and a higher rate of chronic conditions (other than PD), the study groups did not differ in terms of bed days or restricted activity days when controlling for chronic conditions and age. As seen above, there was an association between PD and poor perceived health, which became statistically nonsignificant when adjusting for comorbidity. Thus, poor selfperceived health among prostatics could partially be explained by comorbidity. These results are in agreement with the multivariate analyses, where restriction of activity and presence of chronic conditions were associated with poor self-perceived health (model A, Table 5). Medical visits and hospitalizations were higher in the prostatic group as well. This was so even after excluding diseases of the genitourinary system. Although the design of our study does not allow the causal sequence between the variables studied to be established, the results suggest that men reporting PD constitute a subgroup with increased morbidity and health services use. While this is the first epidemiological approach to PD in Spain and one of the few in Europe, the results must be considered cautiously, mainly because BHIS was not specifically designed to estimate prevalence of particular diseases but, rather, overall health status in the general population. Nevertheless, in the absence of adequate epidemiological information on PD, we believe this analysis provides a useful background from which further studies can be conducted.
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA Derbes V de P, Leche S M, Hooker C W. The incidence of benign prostatk hypertrophy among the whites and Negroes in New Orleans. / Urol 1937; 38: 383-88. Lytton B, Emery J M, Harvard B M. The incidence of benign prostatic obstruction. J Urol 1968; 99: 639-45. Morrison A S. Prostatk: hypertrophy in Greater Boston. J Chron Da 1978; 31: 357-62. Arrighi H M, Metier E J, Guess H A, Fozzard J L. Natural history of benign prostalic hyperplasia and risk of prostatectomy. The Baltimore longitudinal study of aging. Urology 1991; 38 (Suppl 1): 4-8.
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
965
Woolf B. On estimating the relationship between blood group and disease. Ann Human Gen 1955; 19: 251-53. Kleinbaum D G, Kupper L L, Morgenstem H. Epidemiologic Research: Principles and Quantitative Methods. Belmont, California: Lifetime Learning Publications, 1982. Fleiss J L. Statistical Methods for Rates and Proportions, 2nd ed. New York: John Wiley 1981, pp 212-25. Cayuela A, Lacalle J R, Gili M. Analysis of cohort mortality from prostatic cancer in Spain, 1951-1983. J Epidemiol Community Health 1989; 43: 249-52. Ministerio de Sanidad y Consumo. Encuesta Nadonale de Salud. Madrid: Ministerio de Sanidad y Consumo, Subdirecci6n General de Informaci6n Sanitaria y Epidemiologfa, 1989. Departamento de Sanidad y Consumo. Encuesta de Salud de la Comunidad Autdnoma Vasca. Serie estadisticas y documented de trabajo n° 14. Vitoria-Gasteiz: Gobierno Vasco, Departamento de Sanidad y Consumo, 1987. Palacio J, Palario F. Enquesta de salul de Reus 1987/88. Reus: Negociat de Salut Publka, Ajuntament de Reus, 1989. National Center for Health Statistics. Current Estimates from the National Health Interview Survey, 1989. Vital and Health Statistics. Series 10, no 176. Maryland: NCHS, 1990. Donovan J L, Frankel S J, Abrams P. Prevalence of benign prostatk hyperplasia (letter). Lancet 1991; 338: 1076-77. Kroeger A. Health interview surveys in developing countries: a review of the methods and results. Int J Epidemiol 1983; 12: 465-81. Sanjose S, Ant6 J M, Alonso J. Comparacion de la informaci6n obtenida en una encuesta de salud por entrevista con los regjstros de Atenci6n Primaria. Cac Sanit 1992; 27: 260-64. Harlow S D, Linet M S. Agreement between questionnaire data on epidemiologic research. Am J Epidemiol 1989; 129: 233-48. Bang K M, Gergen P J, Carroll M. Prevalence of chronic bronchitis among US Hispanic? from the Hispanic Health and Nutrition Examination Survey, 1982-84. Am J Public Health 1990; 80: 1495-97. Holbrook T L, Wingard D L, Barrett-Connor E. Self-reported arthritis among men and women in an adult community. J Community Health 1990; 15: 195-208. La Vecchia C, Pagano R, Negri E, Decarli A. Smoking and prevalence of disease in the 1983 Italian National Health Survey. Int J Epidemiol 1988; 17: 50-55. Ant6 J M, Company A, Domigo A, Clos J. Aproximaci6 a 1'epidemiologia de la diabetis a la ciutat de Barcelona. Gaseta Sanitaria de Barcelona 1985; 4: 11-16. Goldstein M, Siegel J M, Boyer R. Predicting changes in perceived health status. Am J Public Health 1984; 76: 611-14. Idler E L, Kasl S V, Lemke J H. Self-evaluated health and mortality among the elderly in New Haven, Connecticut, and Iowa and Washington Counties, Iowa, 1982-1986. Am J Epidemiol 1990; 131:91-103. Bush T L, Miller S R, Golden A L, Hale W E. Self-report and medical record report agreement of selected medical conditions in the elderly. Am J Public Health 1989; 79: 1554-56. Scott G. Prevalence of Chronic Conditions of the Genitourinary, Nervous Endocrine, Metabolic, and Blood-Forming Systems and Other Selected Chronic Conditions. Maryland: National Center for Health Statistics. Vital and Health Statistics, Series 10, No 109, 1973.
(Revised version received May 1992)
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Sidney S, Quesenberry C P, Sadler M C « al. Incidence of surgically treated benign prostatic hypertrophy and of prostate cancer among blacks and whites in a prepaid health care plan. Am J Epidemiol 1991; 134: 825-29. Glynn R J, Campion E W, Bouchard G R, Silbert J E. The development of benign prostatic hyperplasia among volunteers in the Normative Aging Study. Am J Epidemiol 1985; 121: 78-90. Fowler F J, Wennberg J E, Timothy R P, el al. Symptoms status and quality of life following prostatectomy. JAMA 1988; 259; 3018-22. Epstein R S, Deverka P A, Chute C O « al. Urinary symptom and quality of life questions indicative of obstructive benign prostatic hyperplasia. Urology 1991; 38 (Suppl 1): 20-26. Ball A J, Feneley R C L, Abrams P H. The natural history of untreated 'prostatism'. Br J Urol 1981; 53: 613-16. Ekman P. Benign Prostatic Hyperplasia epidemiology and risk factors. Prostate 1989; 2 (Suppl): 23-31. Schroder F H, Blom J H M. Natural history of benign prostatic hyperplasia. Prostate 1989; 2 (Suppl): 17-22. Jakobsen H, Torp-Pedersen S, Juul N. Ultrasonic evaluation of age-related human prostatic growth and development of benign prostatic hyperplasia. Scand J Urol Nephrol 1988; 107 (Sappl): 26-31. Garraway W M, Collins G N, Lee R J. High prevalence of benign prostatic hypertrophy in the community. Lancet 1991; 338:' 469-71. Gittes R F. Carcinoma of the prostate. N Engl J Med 1990; 324: 236-^5. Wennberg J E, Roos N, Sola L, Schori A, Jaffe R. Use of daims data systems to evaluate health care outcomes. JAMA 1987; 257: 933-36. Barry M J. MuUey A G, Fowler F J, Wennberg J W. Watchful waiting versus immediate transurethral resection for symptomatic prostatism. JAMA 1988; 259: 3010-17. Roos N P, Wennberg J E, Malenka D J el al. Mortality and reoperation after open and transurethral resection of the prostate for benign prostatic hyperplasia. N Engl J Med 1989; 320: 1120-24. 20 Roos N P, Ramsey E W. A population-based study of prostatectomy: outcomes associated with different surgical approaches. /{/ro/1987; 137: 1184-88. Malenka DJ, Roos N, Fisher ES el aJ. Further study of the increased mortality following transurethral prostatectomy: a charlbased analysis. J Urol 1990; 144: 224-28. / 22 Andersen T F, Bronnum-Hansen H, Sejr T, Roepstorff C. Elevated mortality following transurethral resection of the prostate for benign hypertrophy! But why? Med Care 1990; 28: 870-81. Alonso J, Ant6 J M. Enquesta de Salul de Barcelona 1986. Barcelona: Ajuntament de Barcelona, Area de Salul Publics, 1989. Armhage P, Berry G. Statistical Methods in Medical Research. 2nd ed. Oxford: BUckweU Scientific Publications, 1985 pp 177-20.
25
International Journal of Epidemiology © International Epktemiotogical Association 1992
Epidemiology of Prostatic Disorders in the City of Barcelona ESTEVE FERNANDEZ. MIQUEL PORTA. JORDI ALONSO AND JOSEP M ANTO
ing to the Jewish religion.8 Twenty per cent of 318 presurgical BPH patients studied by Fowler9 rated their health as fair or poor, and significant quality of life problems have been associated with BPH.10 These figures all but underline the scarcity of epidemiological information currently available on the health status of men suffering PD. The primary objective of this analysis was to estimate the prevalence of PD in the city of Barcelona, and to analyse sociodemographic characteristics, selfperceived health, use of health services and lifestyle factors of men reporting PD.
While the burden disorders of the prostate inflict on elderly males is significant1"16 and the treatment of benign prostatic hyperplasia (BPH) is currently the object of heated controversy,17"22 little is known about the epidemiological characteristics of such disorders. Based on five autopsy studies Berry et al? estimated the overall prevalence of histological BPH to increase from 8% among 40 year old men to over 70"% in men over 70. Similar prevalence figures of clinically diagnosed BPH have been reported in prospective longitudinal studies6 but higher figures may be found when strict diagnostic criteria are applied.15 The incidence of clinical BPH found in the Normative Aging Study8 ranged between 31.3 per 1000 person-years (males aged 50-59 years) and 59.2 per 1000 personyears (males aged 70-87 years). Prevalence of BPH appears to be somewhat higher among Blacks and Jewish people. Yet, the relationship with other factors, such as smoking, coffee drinking, or marital status, is not well-established. '•3-s-13 An increased rate of surgery for prostatic disorders (PD) was found for subjects in low socioeconomic groups, nonsmokers and men belong-
MATERIAL AND METHODS The study is based on data from the 1986 Barcelona Health Interview Survey (BHIS). A detailed description of methods has been published elsewhere.23 In summary, BHIS is a cross-sectional study of a random sample of the noninstitutionalized population of the city of Barcelona, based on the 1981 Municipal Census (revised in 1985). The sample was stratified by municipal district and by family size. All individuals were selected in every household (sample unit). Detailed rules were established to address nonresponders and substitutions. Sixteen per cent of households were replaced and family nonresponse rate was n.5°?o. The final sample included 6894 individuals: 3231 men and 3663 women. The greatest error for variables with a frequency about 50% was ± 1 % , with an a error of
Dcpartament d'EpidemiologU i Salut Publica, Institut Municipal d'lnvestigacid Medica, Universiuu Autbnoma de Barcelona, Passeig Maritim 25-29, E-O8OO3 Barcelona, Spain. Reprint requests: Dr Miquel Porta. Presented to the 1991 German and English Language Regional European Meeting of the International Epidemiological Association (IEA), Basel, Switzerland, 29-31 August 1991. Book of abstracts: 142.
959
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Fernandez E (Departament d'Epidemiologia i Salut Publica, Insthut Municipal d'Investigaci6 Medica, Universrtat Autbnoma de Barcelona, Passeig Marftim 25-29, E-08003 Barcelona, Spain), Porta M, Alonso J and Ant6 J M. Epidemiology of prostatic disorders in the city of Barcelona. Internationa/ Journal of Epidemiology 1992; 21: 959-965 Although disorders of the prostate are among the most prevalent problems in elderty males, little is known about their epidemiological characteristics. The 1986 Barcelona Health Interview Survey (BHIS), a cross-sectional study of a random sample of the noninstitutionalLzed population of the city, was used to estimate the prevalence of prostatic disorders (PD) and to analyse sociodemographic characteristics, self-perceived health, and use of health services among males reporting PD. Ninety-eight out of 1218 males over 45 years old (8%) reported having PD, the prevalence increasing substantially with age. A pattern of increasing prevalence with decreasing occupational class was found. As compared to subjects not reporting PD, individuals reporting PD reported slightly more restricted activity days (prevalence odds ratio [POR] = 1.28; 95% confidence interval [Cl] : 0.52-2.80), more chronic disorders (POR = 4.75; 95% Cl: 2.04-13.53), and worse self-perceived health (POR = 1.55; 95% Cl: 0.92-2.58). Medical visits and hospitalizations were also higher in the prostatic group (P < 0.05). Men reporting PD appear to constitute a subgroup with increased morbidity and health services use.
960
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
kappa statistics27 were computed for the comparison between the answer in 1986 and the 1991 telephone survey. Procedures were implemented under SPSS-X, SAS, and EGRET. The significance level was established at 5% and all tests are two-tailed. RESULTS The overall prevalence of self-reported PD in all males over 45 years was 8%, in males 45-64 years it was 4.6"%, and in those aged 65 or over about 16% (Table 1). Prevalence figures were similar across years of education. As for occupational class, a pattern of increasing prevalence with decreasing class was found. TABLE 1 Prevalence of self-reported prostatle disorder! among males aged >*5 years by age groups and selected sociodemographic characteristics, 1986 Barcelona Health Interview Survey
Prevalence ( f t )
No.
95ft CI*
8.05 4.6 10.1 24.4 27.8
98/1218 39/843 24/238 29/119 5/18
8.0-8.1 3.6-5.9 6.6-14.4 16.7-32.1 7.(M8.4
15.7
59/375
12.4-19.4
Years of education >16 years 9-15 years 1-8 years None
7.5 6.3 9.7 5.1
9/120 21/331 63/647 5/98
3.5-13.3 4.4-9.0 9.7-9.9 1.7-11.1
Occupational class I—II III IV-V VI
5.3 7.8 8.9 10.9
13/243 25/322 50/561 10/92
2.9-8.7 5.4-10.8 6.9-11.2 5.4-18.0
Occupational status Retired Economically active Unemployed Other
15.4 2.7 6.7 12.2
69/449 17/630 6/90 6/49
15.3-15.5 1.7-4.2 2.5-13.2 4.6-24.0
Age A l l ( > 4 5 years) 45-64 yean 65-74 years 75-84 years >85 years >65 years
* 95 per cent confidence interval.
Sociodemographic characteristics of the prostatic and control groups are shown in Table 2. As expected, mean age was greater in the prostatic group, with 4O°7o of subjects being under 65 years, as compared to 72% in the control group (P < 0.001). There were no statistically significant differences in marital status nor in years of education. Although no statistically significant association was found between occupational class and the presence of PD, a greater proportion of men in classes I—II exists in the control group (Table 2).
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
5%. Family members or the family head were directly interviewed at home by trained non-health professionals using a precoded questionnaire that requested information on sociodemographic characteristics, selfperceived health, health services use, and lifestyle. In order to assess the overall prevalence of chronic conditions, the questionnaire also included a list of 34 chronic conditions, one of which was 'disorders of the prostate'. Each of these conditions was specifically read to the interviewee. In the present analysis all males aged 45 years or over reporting PD were identified (case group, n = 98). All males in the same age range not reporting PD were selected as controls (n = 1120). While the age cutoff point allowed some control for potential bias induced by age, further adjustments were carried out through stratified analysis and unconditional logistic regression. Control for comorbidity was carried out in two ways: a) in stratified analyses, through the variable 'chronic conditions' (presence/absence of any chronic condition other than PD); and b) in logistic regression, by using the exact number of chronic conditions (range: 0- ^ 8). In order to assess the accuracy of data concerning PD obtained through the personal interview in 1986, and to estimate the malignant or benign status of reported PD, a telephone survey was conducted between April and September 1991. A random sample stratified by study group and age (n = 60) was selected from the 1218 men included in the study. If after six phone calls without answer evidence was obtained of death or of moving (without possibility of identification), the individual was replaced. The total number of individuals successfully interviewed was 40. All telephone calls were made by the same interviewer (EF), who was blind to the interviewee's answer in 1986. Questions were asked about current or past history of PD. If the answer was affirmative, the time span of the disease was sought, and this was later compared with the answer provided in 1986. On the basis of the subject's description of treatment received, an estimate of the nature of PD was made (benign, malignant or inconclusive). Normality was assessed with the KolmogorovSmirnov test. The t-test and the Mann Whitney U test were used for continuous variables. In contingency tables, when 20% or over of cells had expected counts less than five, Fisher's exact test was used. Confidence intervals for proportions were computed by the exact method.24 In stratified analyses the logit estimator of the prevalence odds ratio (POR)25 was used. Further adjustments were conducted by unconditional logistic regression.26 The overall proportion of agreement and
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA TABLE 2 Sociodemographic differences between the prostatic and the control group
Control group (No. - 1120)
68.7(10.1) 47-91
59.4(9.8) 45-97
0.05). The mean number of bed days per person-year (bed days/ person-year) was 3.4 in the prostatic group and 5.9 in the control group (P = 0.81); among subjects 75 years or over the prostatic group showed a mean of 7.6 bed days/person-year versus 2.0 in the control group (P = 0.42). Individuals reporting PD also reported more restricted activity days (PORa = 1.57, P > 0.05). In order to control for comorbidity, stratification for chronic conditions (presence/absence of any chronic condition other than PD) was next carried out. The age and comorbidity adjusted prevalence odds ratio JPORac] was 0.91 for bed days and 1.28 for restricted activity days (Table 3). The mean of restricted activity days/person-year was slightly greater in the prostatic group (P = 0.10), as was the rate of chronic disorders. Overall, the proportion of men with chronic restric-
tion in their usual activities was greater in the prostatic group (PORa = 1.44, 95% CI : 0.74-2.79). The proportion with any chronic disorder (excluding PD) was greater in the prostatic group (PORa = 4.75, P < 0.05). The most common chronic disorders in the two groups were arthrosis, circulation disorders, high blood pressure, bronchitis/asthma and deafness; all were more prevalent in the prostatic group (P < 0.05 in all cases). Heart disorders, haemorrhoids, hernia, kidney stones, stroke and cataracts were also more commonly reported in the prostatic group (P < 0.05). Self-perceived health was worse in the prostatic group (PORa = 1.76, P < 0.05) (Table 3). Whereas the association becomes statistically nonsignificant when stratifying for comorbidity and age, a 55% excess risk is still apparent (P = 0.101). Health Services Utilization Over 90% of subjects in the two groups were insured under the Spanish National Health System (SNHS). The proportion reporting any outpatient medical visit in the last two weeks before interview was greater in the prostatic group (PORa = 2.40, P < 0.05) (Table 4). So it was for the last 12 months (PORa = 3.45, 95% CI: 1.69-4.91). Prostatic patients were still twice as likely to report an outpatient medical visit than controls after stratifying for the presence of chronic conditions. The mean number of outpatient medical visits/ person-year was greater in the prostatic group (P < 0.001). Main reasons for medical visits in the prostatic group were infectious diseases (21.2% of reported medical visits), skin diseases (21.2%), diseases of the genitourinary system (15.2%) and circulatory system (15.2%); and, in the control group, disorders of the respiratory system (18.1%), circulatory system (14.1%), infectious diseases (12.4%) and skin diseases (12.4%). A lower proportion of men in the control group reported medical visits due to diseases of the genitourinary system (3.4%; P = 0.02). Importantly, when diseases of the genitourinary system were excluded, both the proportion of subjects reporting an outpatient medical visit (PORa = 2.05, 95% CI : 1.21-3.42; PORac = 1.70, 95% CI : 0.99-2.86) and the mean number of outpatient medical visits/person-year (P < 0.001) remained greater in the prostatic group. The SNHS was the main provider of medical care (67.6% in the prostatic group and 72.7% in the control group), and the most frequent setting of the visit was a general practice office (61.8% and 63.7%, respectively). More subjects in the prostatic group reported a hospitalization in the last 12 months before interview (PORac = 2.14, P < 0.05) (Table 4). The number of
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Projutic group (No. - 9 8 )
961
962
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY TABLE 3 Association between seif-reported prostatic disorders and perceived health. Stratified analysis
Age (years) 45-64 65-74 >75
AU
(4) (40)
4.1 3.5
5.1 3.1
— 5.9 5.7 2.9
(10) (66)
10.2 5.9
7.7 5.0
8.0 14.7 9.5 5.9
-
20.5 12.7
4.0 11.1
17.7 41.4 18.3 13.1
(90) (802)
93.7 71.9
89.7 68.2
91.7 100.0 81.6 81.2
—
441 165
415 148
396 451 205 227
(35) (283)
42.7 28.6
51.5 27.3
36.4 30.8
Individuals having had a bed day (ft)* Prostatic group Control group PORa (95ft CO = 1.08 (0.27-3.21) PORac = 0.91 (0.22-2.71) Individuals with restricted activity days (ft)* Prostatic group Control group PORa = 1.57 (0.68-3.33) PORac = 1.28(0.52-2.80) Number of restricted activity days PY Prostatic group Control group Individuals with a chronic disorder (ft) b Prostatic group Control group PORa =» 4.75 (2.04-13.53) Rate of chronic disorders0 Prostatic group Control group Self-perceived health evaluation*1 Prostatic group Control group PORa = 1.76(1.06-2.89) PORac = 1.55 (0.92-2.58)
37.0 34.1
* During last two weeks before interview. Other than prostatic disorders. c Per 100 individuals. Per cent with 'poor' self-perceived health. PORa: age-adjusted prevalence odds ratio. PORac: age and comorbidity adjusted prevalence odds ratio. PY: per person-year.
hospitalizations per 1000 person-years was greater in the prostatic group, too. The main reason for hospitalization was circulation disorders in both groups. As with outpatient medical visits, hospitalizations remained greater in the prostatic group after excluding diseases of the genitourinary system {P < 0.05). Lifestyle variables were also analysed and no major differences were found between the two groups in terms of physical activity, sleep patterns and smoking habits. The proportion of individuals attempting to lose weight was greater in the prostatic group (P < 0.05). Multivariate Logistic Regression Analysis A multivariate analysis through unconditional logistic regression was next carried out to assess the relation-
ship between reporting PD and self-perceived health controlling for other relevant variables. As shown in Table 5 (model A) variables associated with reporting 'poor' (poor, bad or very bad) health were: 1) belonging to a low occupational class, 2) having had a restricted activity day, and 3) reporting a chronic condition (other than 'disorder of the prostate'). Specifically, data show that when adjusting for age, occupational class, restricted activity and chronic conditions, prostatic subjects still had an excess risk of reporting poor health of about 25% (P = 0.42). The OR was 1.69 (P = 0.04) when the first two previous variables were considered, and it was 1.74 (P = 0.035) when the first three previous variables were adjusted for. Finally, the relationship between medical visits and PD was analysed. After controlling for age, occupational class, restricted activity days, chronic
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
(No.)
963
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA TABLE 4
Association between seff-reported prostatic disorders and use of health services. Stratified analysis
Age (years) 45-64 65-74 >75
All
(34) (184)
34.7 16.4
28.2 13.4
44.0 26.3
35.3 19.4
—
15.7 7.7
9.3 6.1
30.2 12.7
12.3 10.1
(15) (74)
15.5 6.7
5.1 5.7
20.8 11.3
23.5 5.0
214.2 74.1
102.5 59.7
280.0 131.4
294.1 67.9
Individuals reporting a medical visit (9i)* Prostatic group Control group PORa (95% CI) = 2.40 (1.42-3.81) PORac = 2.00(1.20-3.29) Number of medical visits PY Prostatic group Control group Individuals reporting any hospitalization (Vt)b Prostatic group Control group PORa » 2.23 (1.11-4.29) PORac = 2.14 (1.05^t.l4) Number of hospitalizations0 Prostatic group Control group ° During last two weeks before interview. During last 12 months before interview. c per 1000 persons per year. PY: per person-year. PORa: age-adjusted prevalence odds ratio. PORac: age and comorbidity adjusted prevalence odds ratio.
conditions, and self-perceived health (model B, Table 5) the association remained significant (OR = 1.80, P = 0.041). In simpler models including only some of the previous covariates, the OR ranged between 2.23 and 2.05 (P < 0.05 in all models). Telephone Survey As previously mentioned, through the telephone survey 40 subjects (20 from each study group) were successfully interviewed. The presence of PD in 1986 was confirmed in 19 out of 20 (95%) subjects. Onefifth (4/20) of individuals not reporting a PD in 1986 now did state they were affected in 1986. The overall observed concordance was 87.5*% and the Kappa index was 0.75. The proportion of suspected prostatic cancers inferred from the telephone survey among individuals reporting PD was 10%. DISCUSSION Few epidemiological studies on prostatic disorders have been conducted in Europe and North America and none have been conducted in Spain, except for a descriptive study on prostate cancer mortality.28 A bibliographic review through MEDLINE (period
01.1985-12.1991) and through the Spanish Medical Index (Indice Midico EspaHol) (period 01.1985-12.1990) yielded no other Spanish epidemiological publications on the topic. Other health interview surveys conducted in Spain did not publish prevalence figures for prostatic disorders.29"31 We estimated the prevalence of PD in Barcelona among males 65 years or over to be 15.7%, a figure substantially higher than the 6.4% estimate made by the 1989 National Health Interview Survey in the US for the same age group." The difference is likely to be due either to different perceptions of the disease among the two populations or to a real difference in prevalence of the disease, since both studies followed very similar methodologies for assessing chronic disorders such as PD. Jakobsen et al.u studied the enlargement of the prostate through transrectal ultrasound in 175 men aged 27-70 and found ultrasonic signs of adenoma in 46 prostates, i.e. a 26% prevalence. A study conducted in Scotland13 on 705 men yielded a prevalence for BPH of about 25% in males aged 40-79. In that study BPH was defined by transrectal ultrasonography, urinary symptomatology and peak flow rate; therefore, it is not surprising that the figure is higher than the prevalence rate of self-reported PD we estimated for
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
(No.)
964
INTERNATIONAL JOURNAL OF EPIDEMIOLOGY
TABLE 5 Logistic regression analysis of the relationship between prostatic disorders (PD) and self-perceived health (model A), and between PD and medical visits (model B)
Model B* OR (95% CI)
Self-perceived health11
Medical visits'1
Disorder of the prostate
1.25 (0.72-2.16)
1.80 (1.02-3.17)
Age
0.99(0.98-1.01)
1.03(1.01-1.05)
Occupational class IV-VC III I—II
1.00 0.77(0.54-1.09) 0.64(0.43-0.94)
1.00 1.29(0.86-1.93) 0.74(0.45-1.21)
4.38(2.35-8.17)
12.64(6.47-24.69)
1.47(1.34-1.61)
1.20(1.08-1.33)
Dependent variable Independent variables
Restricted activity11 Chronic conditions
1
Sdf-perceived healthb
1.76(1.19-2.60)
* Based on 1000 observations, 218 obiervations had missing values in dependent or independent variables. b Poor, bad or very bad = 1; Good or very good = 0. c Reference category. d Last two weeks before interview. c Range 0 to 8 ('disorder of the prostate' excluded).
the same age group (6.2*%). Well-defined criteria are undoubtedly needed in many instances, but it is unclear what relation such criteria may bear upon the demand or need for treatment;33 self-perception of disease is possibly a stronger predictor of the demand for care. In this study PD were assessed through a health interview survey, BHIS, which was mainly conducted to gather information about the general status of health in the community. Although health interview surveys are generally not aimed at obtaining prevalence figures for specific health problems,34'35 such surveys have certainly been used when other sources of information were lacking. 36~40 Therefore, although we deemed BHIS to be of value in order to procure a preliminary estimate of the prevalence of PD in our city, several aspects must be borne in mind. First, in this study, as in many health interview surveys, chronic conditions are self-reported by the individual, an objective diagnostic lacking. For common medical conditions (e.g. cataracts, diabetes, hypertension) good agreement has been found between self-reports and medical reports.35 Moreover, self-perception of health has been
ACKNOWLEDGEMENTS This work was partially funded by grants from Fondo de Investigaci6n Sanitaria (FIS 90/0488) and Merck, Sharp & Dohme. The authors are also grateful to Ana Ruig6mez and David J MacFarlane for scientific advice, and to Helena Martinez for technical assistance. REFERENCES 1
2
Barry M J. Epidemiology and natural history of benign prostatic hyperplasia. Urol Clin N Am 1990; 17: 495-507. Berry S, Coffey D, Walsh P, Ewing L. The development of human benign prostatic hyperplasia with age. J Urol 1984; 132: 474-77.
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Model A a OR (95ft Cl)
related to the individuals' need for health care41 and to mortality.42 Nevertheless, chronic conditions may be overreported43 or underreported.36'44 Our telephone survey yielded a good agreement (Kappa = 0.75), although it suggested some degree of underreporting may exist. Second, the questionnaire used by BHIS identified 'disorders of the prostate', which may include both benign and malignant processes. This source of misclassification was also assessed through the telephone survey and about 10% of PD were considered to be likely prostatic cancers. Whereas the prostatic group did report more chronic conditions and a higher rate of chronic conditions (other than PD), the study groups did not differ in terms of bed days or restricted activity days when controlling for chronic conditions and age. As seen above, there was an association between PD and poor perceived health, which became statistically nonsignificant when adjusting for comorbidity. Thus, poor selfperceived health among prostatics could partially be explained by comorbidity. These results are in agreement with the multivariate analyses, where restriction of activity and presence of chronic conditions were associated with poor self-perceived health (model A, Table 5). Medical visits and hospitalizations were higher in the prostatic group as well. This was so even after excluding diseases of the genitourinary system. Although the design of our study does not allow the causal sequence between the variables studied to be established, the results suggest that men reporting PD constitute a subgroup with increased morbidity and health services use. While this is the first epidemiological approach to PD in Spain and one of the few in Europe, the results must be considered cautiously, mainly because BHIS was not specifically designed to estimate prevalence of particular diseases but, rather, overall health status in the general population. Nevertheless, in the absence of adequate epidemiological information on PD, we believe this analysis provides a useful background from which further studies can be conducted.
EPIDEMIOLOGY OF PROSTATIC DISORDERS IN BARCELONA Derbes V de P, Leche S M, Hooker C W. The incidence of benign prostatk hypertrophy among the whites and Negroes in New Orleans. / Urol 1937; 38: 383-88. Lytton B, Emery J M, Harvard B M. The incidence of benign prostatic obstruction. J Urol 1968; 99: 639-45. Morrison A S. Prostatk: hypertrophy in Greater Boston. J Chron Da 1978; 31: 357-62. Arrighi H M, Metier E J, Guess H A, Fozzard J L. Natural history of benign prostalic hyperplasia and risk of prostatectomy. The Baltimore longitudinal study of aging. Urology 1991; 38 (Suppl 1): 4-8.
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
965
Woolf B. On estimating the relationship between blood group and disease. Ann Human Gen 1955; 19: 251-53. Kleinbaum D G, Kupper L L, Morgenstem H. Epidemiologic Research: Principles and Quantitative Methods. Belmont, California: Lifetime Learning Publications, 1982. Fleiss J L. Statistical Methods for Rates and Proportions, 2nd ed. New York: John Wiley 1981, pp 212-25. Cayuela A, Lacalle J R, Gili M. Analysis of cohort mortality from prostatic cancer in Spain, 1951-1983. J Epidemiol Community Health 1989; 43: 249-52. Ministerio de Sanidad y Consumo. Encuesta Nadonale de Salud. Madrid: Ministerio de Sanidad y Consumo, Subdirecci6n General de Informaci6n Sanitaria y Epidemiologfa, 1989. Departamento de Sanidad y Consumo. Encuesta de Salud de la Comunidad Autdnoma Vasca. Serie estadisticas y documented de trabajo n° 14. Vitoria-Gasteiz: Gobierno Vasco, Departamento de Sanidad y Consumo, 1987. Palacio J, Palario F. Enquesta de salul de Reus 1987/88. Reus: Negociat de Salut Publka, Ajuntament de Reus, 1989. National Center for Health Statistics. Current Estimates from the National Health Interview Survey, 1989. Vital and Health Statistics. Series 10, no 176. Maryland: NCHS, 1990. Donovan J L, Frankel S J, Abrams P. Prevalence of benign prostatk hyperplasia (letter). Lancet 1991; 338: 1076-77. Kroeger A. Health interview surveys in developing countries: a review of the methods and results. Int J Epidemiol 1983; 12: 465-81. Sanjose S, Ant6 J M, Alonso J. Comparacion de la informaci6n obtenida en una encuesta de salud por entrevista con los regjstros de Atenci6n Primaria. Cac Sanit 1992; 27: 260-64. Harlow S D, Linet M S. Agreement between questionnaire data on epidemiologic research. Am J Epidemiol 1989; 129: 233-48. Bang K M, Gergen P J, Carroll M. Prevalence of chronic bronchitis among US Hispanic? from the Hispanic Health and Nutrition Examination Survey, 1982-84. Am J Public Health 1990; 80: 1495-97. Holbrook T L, Wingard D L, Barrett-Connor E. Self-reported arthritis among men and women in an adult community. J Community Health 1990; 15: 195-208. La Vecchia C, Pagano R, Negri E, Decarli A. Smoking and prevalence of disease in the 1983 Italian National Health Survey. Int J Epidemiol 1988; 17: 50-55. Ant6 J M, Company A, Domigo A, Clos J. Aproximaci6 a 1'epidemiologia de la diabetis a la ciutat de Barcelona. Gaseta Sanitaria de Barcelona 1985; 4: 11-16. Goldstein M, Siegel J M, Boyer R. Predicting changes in perceived health status. Am J Public Health 1984; 76: 611-14. Idler E L, Kasl S V, Lemke J H. Self-evaluated health and mortality among the elderly in New Haven, Connecticut, and Iowa and Washington Counties, Iowa, 1982-1986. Am J Epidemiol 1990; 131:91-103. Bush T L, Miller S R, Golden A L, Hale W E. Self-report and medical record report agreement of selected medical conditions in the elderly. Am J Public Health 1989; 79: 1554-56. Scott G. Prevalence of Chronic Conditions of the Genitourinary, Nervous Endocrine, Metabolic, and Blood-Forming Systems and Other Selected Chronic Conditions. Maryland: National Center for Health Statistics. Vital and Health Statistics, Series 10, No 109, 1973.
(Revised version received May 1992)
Downloaded from http://ije.oxfordjournals.org/ at The University of British Colombia Library on June 27, 2015
Sidney S, Quesenberry C P, Sadler M C « al. Incidence of surgically treated benign prostatic hypertrophy and of prostate cancer among blacks and whites in a prepaid health care plan. Am J Epidemiol 1991; 134: 825-29. Glynn R J, Campion E W, Bouchard G R, Silbert J E. The development of benign prostatic hyperplasia among volunteers in the Normative Aging Study. Am J Epidemiol 1985; 121: 78-90. Fowler F J, Wennberg J E, Timothy R P, el al. Symptoms status and quality of life following prostatectomy. JAMA 1988; 259; 3018-22. Epstein R S, Deverka P A, Chute C O « al. Urinary symptom and quality of life questions indicative of obstructive benign prostatic hyperplasia. Urology 1991; 38 (Suppl 1): 20-26. Ball A J, Feneley R C L, Abrams P H. The natural history of untreated 'prostatism'. Br J Urol 1981; 53: 613-16. Ekman P. Benign Prostatic Hyperplasia epidemiology and risk factors. Prostate 1989; 2 (Suppl): 23-31. Schroder F H, Blom J H M. Natural history of benign prostatic hyperplasia. Prostate 1989; 2 (Suppl): 17-22. Jakobsen H, Torp-Pedersen S, Juul N. Ultrasonic evaluation of age-related human prostatic growth and development of benign prostatic hyperplasia. Scand J Urol Nephrol 1988; 107 (Sappl): 26-31. Garraway W M, Collins G N, Lee R J. High prevalence of benign prostatic hypertrophy in the community. Lancet 1991; 338:' 469-71. Gittes R F. Carcinoma of the prostate. N Engl J Med 1990; 324: 236-^5. Wennberg J E, Roos N, Sola L, Schori A, Jaffe R. Use of daims data systems to evaluate health care outcomes. JAMA 1987; 257: 933-36. Barry M J. MuUey A G, Fowler F J, Wennberg J W. Watchful waiting versus immediate transurethral resection for symptomatic prostatism. JAMA 1988; 259: 3010-17. Roos N P, Wennberg J E, Malenka D J el al. Mortality and reoperation after open and transurethral resection of the prostate for benign prostatic hyperplasia. N Engl J Med 1989; 320: 1120-24. 20 Roos N P, Ramsey E W. A population-based study of prostatectomy: outcomes associated with different surgical approaches. /{/ro/1987; 137: 1184-88. Malenka DJ, Roos N, Fisher ES el aJ. Further study of the increased mortality following transurethral prostatectomy: a charlbased analysis. J Urol 1990; 144: 224-28. / 22 Andersen T F, Bronnum-Hansen H, Sejr T, Roepstorff C. Elevated mortality following transurethral resection of the prostate for benign hypertrophy! But why? Med Care 1990; 28: 870-81. Alonso J, Ant6 J M. Enquesta de Salul de Barcelona 1986. Barcelona: Ajuntament de Barcelona, Area de Salul Publics, 1989. Armhage P, Berry G. Statistical Methods in Medical Research. 2nd ed. Oxford: BUckweU Scientific Publications, 1985 pp 177-20.
25
![[Epidemiology of atherogenic dyslipidemia in an urban area of the city of Barcelona].](/assets/img/hold.png)
