Frailty and postoperative urinary tract infection

Background: Among older adults, postoperative urinary tract infection is associated with significant harms including increased risk of hospital readmission and perioperative mortality. While risk of urinary tract infection is known to increase with age, the independent association between frailty and postoperative urinary tract infection is unknown. In this study we used 2014–2018 data from the U.S. National Surgical Quality Improvement Program (NSQIP) to investigate whether frailty is an independent risk factor for postoperative urinary tract infection, controlling for age and other relevant confounders. Methods: Frailty was assessed using the modified Frailty Index. Postoperative urinary tract infection was defined as any symptomatic urinary tract infection (of the kidneys, ureters, bladder, or urethra) developing within 30 days of the operative procedure. To examine associations between frailty and other specific factors and postoperative urinary tract infection, chi squared tests, students t-tests, and logistic regression modelling were used. Results: Urinary tract infection was identified after 22,356 of 1,724,042 procedures (1.3%). In a multivariable model controlling for age and other patient and surgical characteristics, the relative odds for urinary tract infection increased significantly with increasing frailty score. For example, compared to a frailty score of 0, the relative odds for urinary tract infection for a frailty score of 3 was 1.50 (95% confidence interval 1.41, 1.60). The relative odds associated with the maximum frailty score (5) was 2.50 (95% confidence interval 1.73, 3.61). Conclusions: Frailty is associated with postoperative urinary tract infection, independent of age. Further research should focus on the underlying mechanisms and strategies to mitigate this risk among frail adults.