Seasonal variations in overactive bladder drug prescription rates in women: a nationwide population-based study

Purpose Colder seasons can aggravate lower urinary tract symptoms, especially an overactive bladder (OAB). This aspect has been extensively studied in men and rarely in women. We investigated whether colder seasons influence OAB-drug prescription rates (OAB-DPRs) in women. Methods Women aged > 18 years were selected from the Korean Health Insurance Review and Assessment Service-National Patient Sample data between 2012 and 2016. OAB-DPR was calculated according to age and seasonal groups. The prescription rates in summer (June, July, and August) and winter (January, February, and December) months were compared. Sub-analysis was performed according to age group. Results In total, 3,061,343 adult women were included. The overall OAB-DPR was 3.75% (114,940/3,061,343). Overall OAB-DPRs in summer and winter were 1.41% (43,090/3,061,343) and 1.54% (47,038/3,061,343), respectively ( p < 0.001). Seasonal variations in OAB-DPRs differed by age group ( p < 0.001): OAB-DPRs were significantly lower in winter than in summer months in women aged < 50 years (odds ratio 0.942; 95% confidence interval 0.918–0.967; p < 0.001), but significantly higher in winter than in summer months in women aged ≥ 50 years (odds ratio 1.153; 95% confidence interval 1.135–1.171; p < 0.001). Conclusion In this study, a correlation was noted between OAB-DPR and seasons. OAB-DPRs were higher in the summer in women aged < 50 years and higher in the winter in women aged ≥ 50 years. Our findings suggest that female hormonal status may be involved in the contradictory effect of seasons on OAB symptoms.