Modified reporting of positive urine cultures to reduce inappropriate antibiotic treatment of catheter-associated asymptomatic bacteriuria (CA-ASB) among inpatients, a randomized controlled trial

Abstract

Objective: To determine whether modified reporting of positive urine cultures collected from indwelling catheters improved treatment decisions without causing harm. Design: Prospective, unblinded, randomized control trial. Setting: Two tertiary-care hospitals. Participants: Overall, 100 consecutive positive urine cultures collected from catheterized inpatients were randomized between standard and modified laboratory reporting between November 2018 and June 2019. Exclusion criteria were pregnancy, current antibiotic treatment, ICU or urology admission, or neutropenia. Intervention: The modified report included significant growth without providing identification, quantification, or susceptibility. The standard report included identification, quantitation and susceptibility. Diagnosis of catheter-associated asymptomatic bacteriuria (CA-ASB) and catheter-associated urinary tract infection (CA-UTI) followed published criteria, using prospective chart review. The appropriate antibiotic treatment was defined as treatment of CA-UTI, and no treatment of CA-ASB. Patients were followed for 7 days. Results: Of 543 urine cultures, 443 (82%) were excluded. Of 100 patients, 75 (75%) had CA-ASB and 25 (25%) had CA-UTI. Treatment was given to 45 of 75 CA-ASB patients (60%) and all 25 CA-UTI patients (100%). Appropriate treatment rate was higher in the modified reporting arm than in the standard reporting arm: 57% vs 50% (+7.4%; relative risk [RR], 1.15; P = .45). Untreated CA-ASB was higher in the modified reporting arm: 45% vs 33% (+12%; RR, 1.36; P = .30). The standard report was requested for 33% of modified reports. Furthermore, 4 deaths and 26.9% adverse events occurred in the modified reporting arm, and 3 deaths and 41.3% adverse events occurred in the standard reporting arm. Conclusions: Modified reporting increased the appropriateness of treatment, and may be safe. Clinical trials identifier: ClinicalTrials.gov#NCT03488355.

Modified reporting of positive urine cultures to reduce treatment of asymptomatic bacteriuria in long-term care facilities: a randomized controlled trial

“…The MR does not change the provider’s beliefs about the significance of the urine culture result. For this reason, MR may have less impact in influencing treatment decisions in LTCFs compared with acute care, where we previously reported a significant difference, 7 if LTCF providers’ beliefs strongly favour treatment of ASB compared with acute care providers. Our study was powered based on the improvement observed using the same intervention in acute care hospitals, but the observed impact in LTCFs was less.…”

“…The effect size was estimated from our previous study, which reported an increase in appropriateness of treatment from 29/55 (52.7%) in the SR to 44/55 (80.0%) in the MR. 7 For a comparison of proportions between two equal groups, accepting a significance level of 5% and statistical power of 80%, a sample size of 2 N = 90 participants was calculated. To account for missing data or loss to follow-up, 100 participants were recruited.…”

“… 6 We performed two randomized trials previously to evaluate modified reporting of positive urine cultures in acute care, demonstrating improvement in treatment appropriateness in the modified reporting arm. 7 , 8 Appropriate treatment was defined as both treatment for UTI and lack of treatment for ASB, since the intervention is designed to reduce treatment of ASB without reducing treatment of UTI. The aim of this study was to apply this same modified reporting intervention in LTCFs, to determine if modified reporting improved the appropriateness of ASB/UTI treatment decisions.…”