Underweight, dementia, and not being completely independent in bowel management are risk factors for urinary incontinence among older people

Despite the known relationship between frailty and urinary incontinence, the components of frailty that are important in managing urinary incontinence remain unclear. This study aimed to investigate physical factors that influenced urinary incontinence. This prospective observational study included patients admitted to the rehabilitation ward of our hospital from July 2020 to June 2022. Patients’ data were collected during the week before their discharge. Patients who needed diaper changes because of urine contamination were defined as incontinent and others as continent. Univariate and multivariate analyses were used to analyze differences between the two groups by age, sex, medical history, body mass index, serum albumin levels, Mini-Mental State Examination scores, Functional Independence Measure motor items (excluding bladder management), grip strength, gait speed, lower limb muscle strength, posture when seated on the toilet, residual urine volume, medication for lower urinary tract symptoms, and polypharmacy. Of 121 patients, 104 (38 men, 66 women) were included in our analyses. Patients’ median age was 81 years (range 56–101 years). The risk factors for urinary incontinence identified in the multivariate analysis were: history of dementia (odds ratio [OR] 19.80, 95% confidence interval [CI]: 2.31–170.00; p = 0.00646), body mass index < 18.5 kg/m 2 (OR 7.09, 95% CI: 1.36–36.90; p = 0.0201), and non-completely independent bowel management (OR 7.19, 95% CI: 1.29–40.16; p = 0.0245). We concluded that dementia, low body mass index, and non-completely independent bowel management are associated with urinary incontinence among older people. • A BMI < 18.5 kg/m 2 is a risk factor for urinary incontinence in frail patients. • A history of dementia is also a risk factor for urinary incontinence. • Non-independence in bowel management is a risk factor for urinary incontinence. • A comprehensive approach is needed to treat urinary incontinence in frail patients.