Nocturia ≥ 3/Night and 5-Year Fragility Fracture Risk in Older Urology Outpatients.

Abstract

Aim: To evaluate whether nocturia ≥ 3/night stratifies 5-year fragility-fracture risk in older urology outpatients and to explore its prognostic performance alongside the N-QoL and IPSS.

Methods: We conducted a retrospective cohort study of urology outpatients aged ≥ 65 years at Hachinohe City Hospital, Japan, between 2015 and 2024. After exclusion of patients with prior fragility fracture, bone metastasis, or pathological fracture, and application of a 3-month landmark, 2290 participants were included. The primary outcome was first non-pathological fragility fracture. Bone metastasis and death were treated as competing events. Fine-Gray subdistribution hazard models were adjusted for age, sex, hypertension, and diabetes. To complement effect estimates, standardized 5-year cumulative incidence was estimated using model-based standardization.

Results: Over a median follow-up of 48.1 months, 98 fragility fractures occurred; 42 bone metastases and 18 deaths were treated as competing events. Nocturia ≥ 3/night was associated with higher fracture risk than nocturia < 3/night (subdistribution hazard ratio [sHR] 2.11, 95% confidence interval [CI] 1.41-3.17). Impaired N-QoL was also associated with higher risk (sHR 1.92, 95% CI 1.12-3.30), whereas severe IPSS showed a weaker association (sHR 1.79, 95% CI 1.00-3.22). The standardized 5-year fracture risk was 9.8% for nocturia ≥ 3/night and 4.8% for nocturia < 3/night, corresponding to an absolute difference of 5.0 percentage points.

Conclusions: Nocturia ≥ 3/night was associated with higher 5-year fragility-fracture risk and may prompt consideration of falls and bone-health assessment in older urology outpatients.