Factors associated with persistent urinary incontinence.

Abstract

Many women with urinary incontinence (UI) have symptoms that continue over many years; however, virtually nothing is known about factors that are associated with persistent UI. We studied 36,843 participants of the Nurses' Health Study, aged 54-79 years at baseline for the UI study, who provided UI information on biennial questionnaires from 2000 through 2008; follow-up in the Nurses' Health Study is 90%. In total, 18,347 women had "persistent UI," defined as urine leakage ≥1/mo reported on all 5 biennial questionnaires during this 8-year period; 18,496 women had no UI during this period. Using multivariable-adjusted logistic regression, we estimated odds ratios (ORs) of persistent UI vs no UI across various demographic, lifestyle, and health-related factors, which were derived from reports in 2000. Increasing age group, white race, greater parity, greater body mass index (BMI), and lower physical activity levels were each associated with greater odds of persistent UI, as were several health-related factors (ie, stroke, type 2 diabetes, and hysterectomy). Associations with persistent UI were particularly strong for increasing age group (P trend < .0001; OR, 2.75; 95% confidence interval [CI], 2.54-2.98 comparing women aged ≥75 vs <60 years) and greater BMI (P trend < .0001; OR, 3.14; 95% CI, 2.95-3.33 comparing women with BMI ≥30 vs <25 kg/m(2)); moreover, black women had much lower odds of persistent UI compared to white women (OR, 0.27; 95% CI, 0.21-0.34). Factors associated with persistent UI were generally consistent with those identified in previous studies of UI over shorter time periods; however, older age, white race, and obesity were particularly strongly related to persistent UI.