Exploring the association between lifetime physical activity and pelvic floor disorders: study and design challenges

One in four women has moderate to severe symptoms of at least one pelvic floor disorder. Lifetime physical activity, a modifiable risk factor, may theoretically predispose women to, or protect them from, developing pelvic floor disorders. It is neither feasible nor ethical to test this association using the most rigorous (level I) study design.

The aim of this manuscript is to describe the methods for the PHysical ACtivity Study (PHACTS), which encompasses two case-control studies and the development of a registry, and to describe challenges and solutions to study progress to date. For each of the case-control studies, the primary aims are to determine, compared to controls with neither pelvic organ prolapse nor urinary incontinence, whether 1) pelvic organ prolapse or 2) stress urinary incontinence is associated with a) increased or decreased current leisure activity or b) increased or decreased overall lifetime activity (including leisure, household, outdoor, and occupational) measured in MET-hours per week, as well as in strenuous hours per week.

To obtain 175 pelvic organ prolapse cases, 175 stress urinary incontinence cases, and an equal number of age, body mass index and recruitment site matched controls, we plan to enroll 1500 women from about 20 primary care level clinics.

We have encountered various challenges leading to lessons learned about minimizing bias, recruitment from community clinics, the lifetime physical activity instrument used, and data management.

Our experiences can help guide future investigators studying risk factors, particularly physical activity, and pelvic floor disorders.