Statistical analysis
Participants characteristics are shown as percentages or as means and standard deviations. The associations of previous and current physical activity with symptoms of pelvic floor disorders were analyzed using logistic regression models. The confounding factors included in the models were age, BMI, education, physical workload, menopausal status, parity, and hysterectomy status, since it is known that demographical factors as well as factors related to gynaecological history may affect pelvic floor disorders and physical activity. The model assumptions were tested using correlation analysis and inspecting residual plots as well as scatter plots between each continuous predictor and the logit values. Statistical analyses were performed using R and IBM SPSS Statistics 22.0 (SPSS Inc., Chicago, IL). The level of significance was set at p≤0.05.
RESULTS
Differences in the reported frequencies of pelvic floor disorders between larger Phase 1 study sample and the smaller Phase 3 sample were minor, indicating good representativeness of the analytical sample (Table 1). About 55% of women reported to have any type of disorder and about 19% experienced more than one pelvic floor disorder type. Most common disorder types were stress urinary incontinence (40%), constipation or defecation difficulties (17%) and urge urinary incontinence (14%). Feeling of pelvic organ prolapse (5%) and fecal incontinence (3%) were less often reported.
Table 2 shows demographical, gynaecological, and physical activity status in total analytical sample and in participants with different types of pelvic floor disorders. The mean age of the participants was 51.2 (SD = 2.0) years. On average, the participants were slightly overweight according to the mean BMI of 25.5 (SD = 3.7). Most (59%) of them had education lower than bachelor level and half (53%) reported their work-related physical activity as light. i.e. mainly sedentary work. Based on serum concentrations of the circulating hormones and bleeding diaries 28% of the women were categorized as premenopausal, 18% early perimenopausal, 19% late perimenopausal, and 35% postmenopausal. The means for number of gestations and parity were 2.5 and 2.0, respectively. About 8% of women had undergone hysterectomy. Groups of women reporting different types of pelvic floor symptoms were fairly similar except that women with feeling of pelvic organ prolapse were less likely to report mainly sedentary work (36%), were more likely to be postmenopausal (41%), had a little bit higher number of gestations (3.2 [SD = 1.8]) and were more likely to have had hysterectomy (20%) than women in other groups. Furthermore, in comparicon to other groups, group of women with fecal incontinence had highest BMI (27.1) and lowest education level (74% reported secondary education).
The mean for current physical activity was 4.5 MET-h/d (SD = 3.9) for total analytical sample and ranged from 3.6 to 4.4 MET-h/d for women reporting different types of pelvic floor symptoms. With regard to previous physical activity, 24% of the women were inactive, 67% took part in regular physical activity, and 10% did competitive sports during their early adulthood. Most (90%) of the women reporting fecal incontinence had exercised regularly, but only one of them (3%) recalled that she had practiced competitive sports. Women reporting urge urinary incontinence formed the group with highest number of competitive sport athletes during early adolescent (13%).
Simple logistic regression models indicated higher current physical activity to associate only with lower odds of experiencing stress urinary incontinence (OR 0.96, CI 0.93–0.99, p=0.023, Table S1) but not with any other pelvic floor disorder types. However, including early adulthood physical activity, and demographical and gynaecological variables as potential confounding factors into the same model abolished statistical significance of the association (Table 3).
In comparison to not exercising during early adulthood, women with history of competitive sports were more likely to experience urge urinary incontinence according to simple (OR 2.07, CI 1.07–4.00, p=0.031, Table S1) and multiple logistic regression models (OR 2.16, CI 1.10–4.24, p=0.025, Table 3) controlled for current physical activity and several demographical and gynaecological factors. Early adulthood competitive sport participation did not associate with other pelvic floor dysfunction types. Similarly, women with history of regular physical activity were more likely to experience fecal incontinence (OR 4.41, CI 1.05–18.49 p=0.043, Table 3) but no significant associations were found for other pelvic floor disorders