Reducing inappropriate urine cultures through a culture standardization program

Abstract

The objective of this study was to evaluate the impact of a urine culture standardization program that included order indications and urinalysis (U/A) with reflexive culture. The program applied to all adult and pediatric inpatients at an academic medical center; emergency department and ambulatory clinic patients were excluded. The analysis compared outcomes in the pre-implementation (January 2015-May 2016) and post-implementation (July 2016-September 2017) periods. The primary outcomes were urine culture and U/A orders per 1,000 patient days, catheter-associated urinary tract infection (CAUTI) rate per 1,000 catheter days, and urine culture contamination rate per 1,000 patient days. Catheter standardized utilization ratios (SURs) were also examined. The intervention was associated with a significant decrease in urine culture rates by 6.9 cultures per 1,000 patient days (95% CI -4.44, -9.44; P < .0001). The U/A testing rate per 1,000 patient days significantly increased pre-intervention, was not affected acutely by the intervention institution, and significantly decreased post-implementation. The CAUTI rate was not significantly changed by the intervention but did significantly increase post-implementation by 0.2 per 1,000 catheter days (95% CI 0.01, 0.47; P = .04); SURs significantly decreased (0.03; 95% CI -0.003, -0.05; P = .03); and the urine culture contamination rate per month showed no significant change. Sixty-four percent of urine cultures ordered using the reflexive test did not reflex to culture by U/A criteria. A urine culture standardization program led to a significant reduction in urine cultures and did not lead to an increase in U/A testing rates. CAUTI rates increased post-implementation, which may have been confounded by reduced catheter utilization.