VARIATION IN ESTIMATES OF URINARY-INCONTINENCE PREVALENCE IN THE COMMUNITY - EFFECTS OF DIFFERENCES IN DEFINITION, POPULATION CHARACTERISTICS, AND STUDY TYPE

OBJECTIVES: Prevalence estimates for urinary incontinence among commun ity-dwelling adults vary from 2 to 55%. A review of the literature was undertaken to investigate the degree to which differences in definiti ons of incontinence, age, and gender of the populations studied, respo nse rates, measurement techniques, or location could explain differenc es in reported prevalences. DESIGN: A literature search was conducted to locate all studies published in English reporting the prevalence of urinary incontinence in a population-based sample of adults. MEASUREM ENT: Information was abstracted for study size, response rate, type of survey, definition of urinary incontinence, and prevalence of inconti nence by age group and gender. Prevalence by type of incontinence was also abstracted where available. Stratification was used to obtain pre valence estimates specific for age, gender, and frequency of incontine nce. Data were examined for associations between prevalence and survey type, response rate, year, and location of survey. RESULTS: A total o f 21 studies met inclusion criteria. Stratification of reported preval ence by frequency, gender, and age substantially reduced the variation in prevalence estimates. For older women, the estimated prevalence of urinary incontinence ranged from 17 to 55% (median = 35%, pooled mean = 34%), and for daily incontinence it ranged from 3 to 17% (median = 14%, pooled mean = 12%). For older men, incontinence prevalence was es timated to be 11 to 34% (median = 17%, pooled mean = 22%), and 2 to 11 % reported daily incontinence (median = 4%, pooled mean = 5%). Within studies, the prevalence of any incontinence was 1.3 to 2.0 times great er for older women than for older men. Among middle-aged and younger a dults, prevalence of incontinence ranged from 12 to 42% (median = 28%, pooled mean = 25%) for women and from 3 to 5% (median = 4%, pooled me an = 5%) for men. The ratio of prevalence of any incontinence for wome n to men in this age group ranged from 4.1 to 4.5. Stress incontinence predominated in younger women, whereas urge and mixed incontinence pr edominated in older women. There was a tendency for studies using in-p erson interviews to report higher prevalences. CONCLUSIONS: An accurat e estimate of the prevalence of urinary incontinence depends on specif ying the definition of incontinence and the age and gender groups of i nterest.