Purpose: We investigated the effects of comorbidity and urinary incontinence on both generic and incontinence specific quality of life outcome measures, and investigated whether the association between urinary incontinence and quality of life varies by race.
Materials and methods: Study participants were 2,109 women 40 to 69 years old randomly selected from an urban health maintenance organization and interviewed in person for a study of risk factors for urinary incontinence. The sample was racially diverse consisting of 48% white, 18% black, 17% Hispanic and 16% Asian-American women. In addition to incontinence, reproductive and medical history questionnaires, all participants completed the Medical Outcomes Study Short Form 36, a measure of health related quality of life. All participants with daily and weekly incontinence (29%) completed the Incontinence Impact Questionnaire, an incontinence specific quality of life measure. The health maintenance organization's inpatient and outpatient electronic databases were used to calculate a Charlson comorbidity index score for each participant. ANCOVA was used to produce a model adjusting for sociodemographic variables, comorbidity and incontinence frequency. The same model was run for each of 4 racial groupings to examine differences by race/ethnicity.
Results: Urinary incontinence is significantly associated with a decreased quality of life and those with more frequent incontinence have significantly lower quality of life scores. In our model the Charlson score, an objective measure of comorbidity based on hospital and physician records, also has a significant negative impact on quality of life. When comorbidity is controlled, incontinence frequency continues to have a significant negative association with quality of life except among the sickest women. For women with the greatest extent of comorbidity, incontinence frequency is not significantly associated with negative quality of life outcomes. We did not find clear patterns of variation by race.
Conclusions: Urinary incontinence and comorbidity each have an independent and significant role in reducing quality of life outcomes for all but the sickest women.