Bladder emptying method is the primary determinant of urinary tract infections in patients with spinal cord injury: results from a prospective rehabilitation cohort study

Objective To understand the occurrence of and risk factors for urinary tract infections (UTIs) in patients with spinal cord injury (SCI) undergoing specialized SCI rehabilitation in Switzerland. Patients and Methods This study used data collected from 369 patients, who participated in a nationwide rehabilitation cohort for SCI in Switzerland between 2013 and 2017. Information on UTIs as well as their potential determinants, including demographics, lesion characteristics, and time‐updated data on functional independence and bladder management, was used. Multivariable regression methods were applied to perform a time‐updated evaluation of determinants of UTI risk. Results The crude incidence rate (IR) of UTIs was 0.55 UTIs per 100 person‐days (95% confidence interval [CI] 0.49–0.62), the cumulative IR was 43%, and the median length of stay was 122 days. The bladder emptying method at discharge was largely determined by 28 days after admission. Among those using indwelling or assisted intermittent catheterization (IC), the likelihood of self‐IC at discharge was positively related to the level of self‐care independence, negatively related to age at injury, and lower in women than men. Catheter users consistently had higher adjusted IRs for UTI than spontaneous voiders. The IR ratios were: indwelling catheter: 5.97 (95% CI 2.63–13.57); assisted IC: 6.05 (95% CI 2.63–13.94); self‐IC: 5.16 (95% CI 2.31–11.52); test for differences across catheter groups: P = 0.82. Lesion severity and previous UTI had additional but smaller effect sizes. Conclusions Bladder emptying method was identified as the main risk factor for UTI in patients with SCI. As spontaneous voiders had the lowest UTI rate, further research is warranted to reduce voiding dysfunction, for instance using neuromodulation procedures.