Aim of the study
Female urinary incontinence is a common problem with an estimated prevalence between the 20 and 57%. This wide range in reported prevalence could be due to the use of different definitions for urinary incontinence, demographic difference or the way questions are designed. Since most authors do not mention which questions were used to identify women with urinary incontinence, it is difficult to compare data. It is known that quality of life (QOL) can be negatively affected by urinary incontinence. This study was designed to estimate the prevalence of urinary incontinence with a validated questionnaire and to report on the consequences that urinary incontinence may have on physical and emotional health.

Method
A random sample of 1905 women, aged 45 to 70 years old was taken from the population registration office. All women received a questionnaire that contained the Dutch translation of the Urogenital Distress Inventory (UDI) / Incontinence Impact Questionnaire (IIQ)(disease-specific quality of life questionnaire for urinary incontinence) (1), the RAND-36 (generic QOL questionnaire) and the CES-D (depressive symptomatology). Two questions were selected from the UDI as indicators of stress incontinence (do you experience urine leakage related to physical activity, coughing or sneezing?) and urge incontinence (do you experience urine leakage related to a feeling of urgency?). These two items were used to distinguish four groups: women without incontinence, women with only stress incontinence, women with only urge incontinence and women with mixed incontinence. Women who also reported faecal incontinence for liquid or solid stools were excluded from analysis. The four groups were compared for their scores on the RAND-36 and IIQ using ANOVA. Previous factor analysis of the Dutch translation of the IIQ identified a fifth domain with items closely related to embarrassment. A CES-D score > 16 was used to identify women with a probable depression.

Results
A total of 1079 women (60%) responded. Eighty-seven women reported fecal incontinence and were excluded, leaving 992 evaluable women. Of these women 446 (45%) reported no urinary incontinence, 285 (28.7%) only stress incontinence, 53 (5.3%) only urge incontinence and 208 (22.0%) mixed incontinence. Of the 546 women with incontinence 353 answered the questions of the IIQ. Comparing the mean scores of the RAND-36 domains for the four groups showed that only women with mixed incontinence reported a significant worse quality of life on all domains when compared to continent women. There were no differences found between the different types of urinary incontinence. However, with the use of the disease-specific IIQ substantial differences were found between the different types of urinary incontinence as is presented in the Table. A high score indicates a worse QOL.

Women with an urge or mixed incontinence reported a statistical significant, two-fold increased risk of having depressive symptoms (CES-D > 16) when compared to continent women.

Conclusions
The prevalence of urinary incontinence in women aged 45 to 70 years is high (55%). Especially women with mixed incontinence report a worse quality of life when compared to continent women or women with only stress incontinence. A difference in QOL between groups of different types of urinary incontinence was best identified with the IIQ.

Reference
1. Quality Life Res 1994;3:291-306