BACKGROUND

Urinary incontinence (UI) is a common disorder that is increasingly important as our population ages. Less is known about UI in younger women, and few large surveys have been able to determine risk factors by linking their data to patients' medical findings.

METHODS

We conducted a population-based, age-stratified postal survey of 6000 women aged between 30 and 90 years who were enrolled in a large health maintenance organization in Washington State.

RESULTS

The response rate was 64% (n = 3536) after exclusion criteria were applied. The population-based prevalence of UI was 45%. Prevalence increased with age, from 28% for 30- to 39-year-old women to 55% for 80- to 90-year-old women. Eighteen percent of respondents reported severe UI. The prevalence of severe UI also increased notably with age, from 8% for 30- to 39-year-old women to 33% for 80- to 90-year-old women. Older age, higher body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters), greater medical comorbidity, current major depression, a history of hysterectomy, and parity increased the odds of having UI. Not being white and having had only cesarean deliveries decreased the odds of having UI. Major depression (odds ratio, 2.48; 95% confidence interval, 1.65-3.72) and obesity, defined as having a BMI of 30 or greater (odds ratio, 2.39; 95% confidence interval, 1.99-2.87), had the strongest association with UI. Among women with UI, age, BMI, medical comorbidity, current major depression, diabetes, a history of hysterectomy, and having had only cesarean deliveries were significantly associated with severe UI.

CONCLUSIONS

Urinary incontinence is highly prevalent in women across their adult life span, and its severity increases linearly with age. Age, BMI, race, medical comorbidity, current major depression, a history of hysterectomy, parity, and having only had cesarean deliveries are each independent factors significantly associated with the likelihood of having UI.