Prevalence and Correlates of Erectile Dysfunction in Turkey: A Population-Based Study

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1 European Urology European Urology ) 298±304 Prevalence and Correlates of Erectile Dysfunction in Turkey: A Population-Based Study Emre Akkus *, Ates Kadioglu, Adil Esen, Saban Doran, Ali Ergen, Kadri Anafarta, Halim Hattat, Turkish Erectile Dysfunction Prevalence Study Group) Department of Urology, Cerrahpasa School of Medicine, Istanbul University, Istanbul, 34303, Turkey Accepted 15 January 2002 Abstract Objectives: Epidemiologic data indicate that erectile dysfunction ED) is a signi cant problem among men worldwide. However, data do not exist for Turkish men. This study was conducted to determine the prevalence and sociodemographic, medical, and lifestyle correlates of EDin Turkey. Methods: Information was gathered via physician-conducted interviews using a validated questionnaire. Respondents self-rated their EDas ``none,'' ``minimal,'' ``moderate,'' or ``severe''. Bivariate and multivariate analyses were performed on data from a strati ed random sample of 1982 men aged 40 years to quantify the associations between EDand potential covariates. Results: The age-adjusted overall prevalence of EDin Turkey was 69.2% mild 33.2%, moderate 27.5%, severe 8.5%) and increased with age, as did severity of ED. When we consider moderate severe EDcases, the prevalence is 36%. In a multivariate model, increased prevalence of moderate or severe EDwas signi cantly associated with age, residence in eastern Turkey; low educational level; unemployment; or underlying diabetes, hypertension, depression, prostate problems or lower urinary tract symptoms. Conversely, residence in southern Turkey, alcohol consumption, physical activity, and higher income were signi cantly associated with decreased prevalence. Conclusions: EDaffects a high proportion of Turkish men aged 40 years, is correlated with a number of serious medical conditions and the frequency increases with age. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Erectile dysfunction; Turkey; Epidemiology; Prevalence; Age 1. Introduction Erectile dysfunction ED) is de ned as ``the inability to attain and/or maintain penile erection suf cient for satisfactory sexual intercourse'' [1]. Recent surveys in North and South America, Europe, Asia, and Africa have demonstrated that worldwide, EDis a frequent problem for men and consistently increases with age Fig. 1) [2]. A number of sociodemographic factors age, education, income, marital status) [3,4], medical conditions hypertension, diabetes, heart disease, benign * Corresponding author. Tel.: ; Fax: address: emreak@istanbul.edu.tr E. Akkus). prostatic hyperplasia, prostate cancer, renal failure, depression), medical treatments [3,5±14], and lifestyle factors smoking, alcohol consumption, body size, and physical exercise) [15,16] have been correlated with ED. Since sildena l citrate Viagra 1 ) was introduced in April 1998 as an oral treatment for ED, the numbers of men seeking medical attention for EDhas increased rapidly. While EDis a distressing medical condition for men and their partners, medical attention for the treatment of EDalso has the potential to uncover other serious and asymptomatic morbidities early in the course of disease [5,14]. The prevalence and correlates of EDhave differed somewhat among different populations [3,4,12,13,16]. Therefore, knowledge of the local epidemiology can /02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S )

2 E. Akkus et al. / European Urology ) 298± Fig. 1. Prevalence of severe, moderate, and mild EDby age in Turkish men 40 years of age and older in the current study. aid physicians in evaluating individual patients as well as offer clues to the etiology of their ED. There are no epidemiological data on EDin Turkey. Thus, a crosssectional, population-based household survey was conducted to determine the prevalence of EDin Turkish men and to explore sociodemographic, medical, and lifestyle correlates of ED. 2. Methods 2.1. Study population A random sample of households strati ed by age, geographic region, and urban/rural residence was selected to ensure adequate sample size for subgroup analyses. A multi-stage sampling scheme was used. At the rst stage, a systematic random sample of provinces in each region was selected, where the chance of being selected was determined by the population size of the province. Among these selected provinces, the second stage randomly identi ed the streets for urban areas and the villages for the rural areas, where the survey would be carried out. For urban areas, the sampling frame consisted of the list of street names that was based on the 1990 census obtained from the State Institute of Statistics, Prime Ministry, Republic of Turkey. For the rural areas, the sampling frame was the list of villages which are classi ed as rural administrative units by the State Institute of Statistics for each previously selected province. For each street and village, the eld staff was instructed to ll a quota for each age group for every 20 individuals, that consisted a cluster. Younger men were over-sampled to compensate for their expected lower prevalence of ED. All randomly selected households were visited once during the day time in working hours between 8:00 and 17:00 h); if the rst visit was unsuccessful, no return visits or further attempts at contact were made. Population distribution for 1998 was estimated based on the 1990 Turkish census data Survey instrument For sampling and data analysis, the country was divided into ve culturally and socioeconomically distinct regions. Data were collected using a validated questionnaire internal consistency of the questions which were translated and back translated in Turkish) that was used in the P zer Cross-National Study of Erectile Dysfunction [17] not yet published as a peer-reviewed manuscript). Detection of depression levels and prostate diseases were evaluated as described by Weissman et al. and Boyle, respectively [18,19]. A physician trained in recruiting and interviewing techniques administered the questionnaire in the subject's home. Con- dentiality and anonymity were assured. Data regarding demographics, medical conditions and concomitant medications were collected by self-report. No attempt was made to validate the respondents' answers with medical records. EDwas assessed by the following single question. Using the following categories, how would you describe yourself? The response categories corresponding, respectively, to ``no ED'', ``mild minimal) ED'', ``moderate ED'', and ``severe complete) ED'' were: a) always or almost always able to get and keep an erection adequate for satisfactory intercourse; b) usually able to get and keep an erection adequate for satisfactory intercourse; c) sometimes able to get and keep an erection adequate for satisfactory intercourse; d) never able to get and keep an erection adequate for satisfactory intercourse Statistical analyses The total prevalence of EDand the distribution of EDby 10-year age categories were calculated using sampling weights to re ect the total population of Turkish men aged 40 years and older. Proportional odds regression models, which incorporate the ordering of the outcome variable, were used for bivariate crude and age-adjusted associations and for the multivariate model. The odds ratio OR) and 95% con dence interval CI) were calculated for each independent variable. Two-tailed P values 0.05 were considered statistically signi cant. In the multivariate proportional odds regression, full models were tted, then non-signi cant P > 0:1) variables were eliminated in a backward stepwise elimination algorithm, least signi cant rst, to determine the nal model. Those medical conditions of a priori interest were retained in the model regardless of whether they were statistically signi cant. 3. Results 3.1. Response rate Among the total of 6867 households visited, 2158 included an eligible man who completed an interview,

3 300 E. Akkus et al. / European Urology ) 298±304 Table 1 Subject response in randomly selected households Total households visited Eligible man identified Interviewed Refused interview No eligible man Eligibility not ascertained No one home No access to building No information on eligibility Others Response n %) %) %) %) %) %) %) %) %) %) %) frequent reason for failing to obtain an interview was the absence of an eligible man in the household followed by nding nobody at home Table 1). Among households in which an eligible man was identi ed, the response rate was 89% Study sample The study sample was comprised of 1982 Turkish men aged 40 years and older. More than 90% of respondents were married or living with a partner, 85% had some formal education, more than 50% had a sedentary lifestyle, and almost 75% had smoked or chewed tobacco Tables 2 and 3). of which %) were usable. The overall response rate was 44%, calculated by dividing the total number interviewed 2158) by the number of eligible plus the number of unknown eligibility 4901). The most 3.3. Prevalence of ED The age-adjusted overall prevalence of EDin Turkey was 69.2% mild, 33.2%; moderate, 27.5%; severe, 8.5%) and increased from 49.9% in men aged 40± 49 years to 94.7% in men aged 70 years and older Table 2 Bivariate crude and adjusted prevalence ORs for moderate or severe EDby sociodemographic characteristics Characteristic n %) Crude OR 95% CI) Age-adjusted OR 95% CI) Age in years) total n ˆ 1982) 40± ) Not applicable 50± ) ±8.17) *** Not applicable 60± ) ±38.97) *** Not applicable ) ±271.54) *** Not applicable Marital status total n ˆ 1869) Married and living with partner ) Separated, divorced, widowed ) ±9.29) *** ±4.58) *** Never married ) ±2.27) ±5.77) Education total n ˆ 1957) Secondary school or more ) Primary school ) ±2.54) *** ±1.66) Just literate or illiterate ) ±13.68) *** ±4.43) *** Employment status total n ˆ 1982) Currently unemployed ) ±19.61) *** ±6.10) *** Income lira) total n ˆ 1812) <500 million ) 500 million±1 billion ) ±0.34) *** ±0.40) *** >1±1.5 billion ) ±0.32) *** ±0.51) *** >1.5±2 billion ) ±0.23) *** ±0.37) *** >2 billion ) ±0.15) *** ±0.33) *** Region of Turkey total n ˆ 1982) Western ) Central ) ±1.68) * ±1.74) Northern ) ±1.50) ±2.06) Southern ) ±0.64) *** ±0.54) *** Eastern ) ±2.47) *** ±4.54) *** Residence total n ˆ 1982) Rural ) Urban ) ±1.29) ±1.54) * P < 0:05. *** P < 0:001.

4 E. Akkus et al. / European Urology ) 298± Table 3 Bivariate crude and adjusted prevalence OR for moderate or severe EDby medical and lifestyle characteristics Characteristic n %) Crude OR 95% CI) Age-adjusted OR 95% CI) Medical history total n ˆ 1982) Diabetes ) ±7.59) *** ±3.61) *** Hypertension ) ±8.35) *** ±3.66) *** Heart disease ) ±7.50) *** ±2.38) * Ulcer ) ±1.85) * ±2.51) *** Prostate problem any) ) ±16.99) *** ±4.44) *** IPSS total n ˆ 1973) Mild <8) ) Moderate 8±19) ) ±16.89) ** ±5.90) *** Severe >20) ) ±40.93) *** ±11.35) *** Depression CES-D) 1 unit decrease on CES-D ±1.20) *** ±1.26) *** Medications total n ˆ 1982) Diabetes ) ±11.57) ** ±12.83) * Hypertension ) ±3.30) * ±2.38) Heart disease ) ±6.74) ±7.42) Ulcer ) ±1.37) ±1.77) Lifestyle total n ˆ 1982) Tobacco ever use) ) ±0.77) *** ±1.25) Alcohol yes/no) ) ±0.32) *** ±0.59) *** Caffeine yes/no) ) ±0.64) *** ±1.00) Physical activity total n ˆ 1839) Sedentary ) Moderate ) ±0.69) *** ±0.45) *** Active ) ±0.29) *** ±0.30) *** * P < 0:05. ** P < 0:01. *** P < 0:001. Fig. 1). Both the prevalence and severity of ED increased with age. The combined prevalence of moderate plus severe EDincreased markedly with increasing age, from 7.6% in men aged 40±49 years to 33.3% in men aged 50±59 years, 70.2% in men aged 60± 69 years, and 90.1% in men aged 70 years and older Bivariate correlates of ED The crude and age-adjusted bivariate associations OR between EDand potential covariates are shown in Tables 2 and 3, comparing no EDplus mild EDwith moderate plus severe ED, estimated by proportional odds regression. Age was a strong confounder for many of the signi cant associations. In the age-adjusted bivariate analyses, sociodemographic variables positively associated with increased prevalence of EDwere: being separated, divorced, or widowed; having no formal schooling; and current unemployment Table 2). Compared with men living in western Turkey, men living in southern Turkey had a signi cantly lower prevalence of ED, those living in eastern Turkey had an increased prevalence, and men living in central or northern Turkey had a similar prevalence. Medical conditions positively associated with ED Table 3) included history of diabetes, hypertension, heart disease, ulcer, or any prostate problem; depression measured by a shortened 5-item) version of the 20-item Center for Epidemiologic Studies Depression Scale CES-D) [18]; and lower urinary tract symptoms corresponding to an International Prostate Screening Score IPSS) of 8 or higher [19]. IPSS was associated with the degree of ED Table 3). Among lifestyle factors, both alcohol consumption and moderate or greater physical activity were inversely associated with the prevalence of ED Table 3). Smoking was not a signi cant correlate Multivariate model Age remained a strong correlate of EDin the nal multivariate proportional odds regression model Table 4). Other sociodemographic variables that were signi cant in bivariate analyses and remained signi cant, albeit attenuated, in the multivariate model, included having no formal schooling, current

5 302 E. Akkus et al. / European Urology ) 298±304 Table 4 Multivariate proportional odds model Characteristic Adjusted OR a 95% CI) Age per year) ±1.19) *** Marital status Married or living with partner Separated, divorced, or widowed ±2.67) Education Secondary school or more Primary school ±2.03) Just literate or illiterate ±2.91) * Employment status Currently unemployed ±3.34) *** Income lira) <500 million 500 million±1 billion ±0.67) *** >1±1.5 billion ±1.12) >1.5±2 billion ±0.82) * >2 billion ±0.87) * Region of Turkey Western Central ±1.94) Northern ±2.00) Southern ±0.52) *** Eastern ±2.80) * Medical history Diabetes ±3.33) *** Hypertension ±2.20) * Heart disease ±1.91) Ulcer ±1.89) Prostate problem any) ±2.55) Depression CES-D) 1 unit on CES-D ±1.13) * IPSS Mild <8) Moderate 8±19) ±3.33) *** Severe >20) ±10.41) *** Lifestyle Alcohol yes/no) ±0.85) ** Physical activity Sedentary Moderate ±0.70) *** Active ±0±34) *** a Adjusted for all other variables in table. * P < 0:05. ** P < 0:01. *** P < 0:001. unemployment, higher income, and southern and eastern region of residence. Of the medical conditions, diabetes, hypertension, depression, prostate problems, or a moderate/severe rating on the IPSS remained signi cantly correlated with ED, while heart disease and ulcer did not. Alcohol consumption and physical activity remained signi cantly inversely related to ED see Table 4 for OR). 4. Discussion Since the rst introduction of sildena l, the epidemiology of EDhas been well studied, probably re ecting increased interest in the diagnosis and treatment of ED. This is the rst population-based study of the prevalence and correlates of EDin Turkey. As in all other surveys, including those in the US [3,4,20], Australia [21], Thailand [22], the UK [23], France [24], and Finland [25], we observed that increasing age was correlated with both increasing prevalence of any degree of EDas well as the severity of ED. In the P zer Cross-National Study of the Prevalence and Correlates of ED[17], the age-adjusted overall prevalence of ED mild, moderate, and severe) was 81.1% in Japan, 69.8% in Italy, 62.1% in Malaysia, and 39.9% in Brazil. Utilizing the same survey instrument, we found the overall prevalence of EDin Turkey to be 69.2%. When we consider moderate severe ED cases, the prevalence is 36%. Recent epidemiological studies on EDin Spain and in Cologne revealed lower prevalence rates 18.9 and 19.2%, respectively) [26,27]. These differences in prevalence may re ect actual population differences and/or cultural differences in the perceptions of and attitudes toward ED, or this difference may be due to the age ranges of these two studies Spain study age range is 25±70 years, Cologne study age range is 30±80 years). Also, different methodologies were used: self-administered mail-in questionnaires in Japan, a telephone survey in Italy, in-person interviews in Brazil; a combination of telephone and in-person interviews in Malaysia; and in-person physician interviews in Turkey. Two US studies have reported lower prevalence rates. The Massachusetts Male Aging Study MMAS) [2] found an overall prevalence of EDof 52% in a sample of highly educated men aged 40±70 years living in suburban Boston. However, the MMAS had no direct measure of ED, instead depending on a derived variable constructed post-hoc from a clinical convenience sample [28]. The National Health and Family Life Survey NHFLS), a population-based survey of US adults aged 18±59 years [4], found that, in the age groups overlapping the current study, 11% of men aged 40±49 years and 18% of men aged 50±59 years reported having trouble ``maintaining or achieving an erection''. How the de nition of EDin the NHFLS correlates with the de nition in the current study is unclear. As in the MMAS [29], socioeconomic status was correlated with ED. In this, as in other studies [3,4], men who were separated, divorced, or widowed had a

6 E. Akkus et al. / European Urology ) 298± higher prevalence of EDthan those who were married or living with a partner. The differences among geographic regions found in Turkey may re ect interregional cultural and socioeconomic differences. For example, eastern Turkey, where the prevalence of EDis the highest, is somewhat isolated by mountainous terrain and thus, the inhabitants have retained a more traditional lifestyle and a lower socioeconomic status than residents of western Turkey. EDis largely a vascular disease [6±9], consistent with the nding of a higher prevalence of EDin men with diabetes and hypertension. Prostate problems and lower urinary tract symptoms were associated with ED, as found in other surveys [10,24]. Depression, which has been associated with EDin other studies [11,12], was also a correlate of EDin this multivariate model. Alcohol consumption was inversely correlated with EDin this study. Similarly, the Health Professionals Follow-up Study [16] found that moderate drinkers one±two drinks per day) had a lower prevalence of ED than either non-drinkers or heavy drinkers. The MMAS, however, found a slightly elevated prevalence of EDwith alcohol consumption [3]. Moderately active and very active men had lower prevalence of EDin both this study and the Health Professionals Follow-up Study [16]. As in the Health Professionals Follow-up Study [16] and the MMAS [3], there was no association between smoking and EDin the current study possibly due to the overwhelming majority of smokers in the study population). In contrast, others [15] have found smoking to be associated with ED. The primary strength of this study is its large, population-based national sample, which ensured adequate statistical power to determine the prevalence and degree of EDstrati ed by age and geographic region, and to explore the association of EDwith a number of potential covariates. The use of physician-interviewers may have conferred an advantage over other methods of data collection, with men more willing to discuss sensitive psychological and sexual issues with adoctor. The major limitation of the study is the poor response rate 44%). The study protocol required physicianinterviewers to personally visit each randomly selected household and allowed only one visit to each household with no introductory letter or attempted follow-up of non-responders. These constraints prevented contact with a high proportion of households. However, in households in which an eligible man was identi ed, the response rate was 89%. Furthermore, it is unlikely that men in non-contacted households differed substantially from those contacted with respect to EDand other variables. As a cross-sectional questionnaire survey, data collection was limited to self-reports. Thus, asymptomatic medical conditions such as hypertension and diabetes are almost certainly substantially underreported, which is likely to result in non-differential misclassi cation and attenuation of the prevalence ORs. An other limitation to the study is that; although the response rate is small we could not provide data to compare the demographics between responders and non-responders. 5. Conclusions In Turkey, as in other countries, EDis a very common condition, increasing in prevalence and severity with increasing age. Correlates of EDidenti ed in this study population are consistent with some other studies of EDin different populations around the world. These correlates can aid physicians in identifying and evaluating patients with ED. Acknowledgements This study was completed with the maximum efforts of the following colleagues. We are very grateful for their hard work and their positive feelings about the teamwork. Mehmet Z. Sungur, Temel Yilmaz, Engin Eker Turkish Erectile Dysfunction Prevalence Study Group), Fatih Sarioz, Huseyin Akbulut, Feyza Tevruz P zer Ilaclari Ltd. Sti., Istanbul, Turkey), Dale B. Glasser P zer Inc., New York, USA), Alfredo Nicolosi, and Marco Villa National Research Council, Milan, Italy). References [1] NIH Consensus Conference. Impotence. NIH Consensus Development Panel on Impotence. JAMA, 1993;270:83±90. [2] Robertson C, Boyle P, Mazzetta C, Keech M, Fourcade R, Hobbs R, et al. The prevalence of urinary disease in households across four countries: the UREPIK Study. J Urol 2001;165:46. [3] Feldman HA, Goldstein I, Hatzichristou DG, Krane RJ, McKinlay JB. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol 1994;151:54±61. [4] Laumann EO, Paik AMA, Rosen RC. Sexual dysfunction in the United States: prevalence and predictors. JAMA 1999;281:537±44. [5] Curkendall SM, Jones JK, Pezzulo JC. Relationship of medical detection of erectile dysfunction to detection of related diseases after

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