Abstract
BACKGROUND AND OBJECTIVE: Overactive bladder (OAB) is often treated with anticholinergic medications, but concerns have emerged regarding their potential long-term risk of dementia. Our objective was to investigate whether the use of OAB anticholinergics, as compared with beta-3 agonists, is associated with new-onset dementia individuals under 65 yr of age. METHODS: A retrospective, propensity-weighted cohort study was conducted using population-based data from Canada. The study population included people aged 18-64 yr who started a prescription of an OAB anticholinergic medication or the beta-3 agonist mirabegron. Inverse propensity of treatment weighting was used to balance baseline characteristics. The primary outcome was the incidence of dementia. The Fine-Gray subdistribution hazard model, adjusted for age and sex, was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). KEY FINDINGS AND LIMITATIONS: A total of 57 975 patients were included in the study, with 48 454 in the OAB anticholinergic group (305 724 person-years of follow-up) and 9521 in the beta-3 agonist group (34 605 person-years of follow-up). After propensity score weighting, there was no significant difference in the risk of dementia between OAB anticholinergic users and beta-3 agonist users (HR 0.99, 95% CI 0.86-1.15, p = 0.9). The study limitations are the risk of misclassification and residual confounding. CONCLUSIONS AND CLINICAL IMPLICATIONS: Among people <65 yr of age, the use of OAB anticholinergics versus beta-3 agonists was not significantly associated with dementia. This serves to reassure physicians and patients who use these medications in younger adults. PATIENT SUMMARY: In adults aged 18-64 yr who have overactive bladder, the use of different types of oral medications are not associated with dementia.