A Statewide Quality Initiative to Reduce Unnecessary Antibiotic Treatment of Asymptomatic Bacteriuria

Abstract

ImportanceHospitalized patients with asymptomatic bacteriuria (ASB) often receive unnecessary antibiotic treatment, which increases antibiotic resistance and adverse events.ObjectiveTo determine whether diagnostic stewardship (avoiding unnecessary urine cultures) or antibiotic stewardship (reducing unnecessary antibiotic treatment after an unnecessary culture) is associated with better outcomes in reducing antibiotic use for ASB.Design, Setting, and ParticipantsThis 3-year, prospective quality improvement study included hospitalized general care medicine patients with a positive urine culture among 46 hospitals participating in a collaborative quality initiative, the Michigan Hospital Medicine Safety Consortium. Data were collected from July 1, 2017, through March 31, 2020, and analyzed from February to October 2022.ExposureParticipation in the Michigan Hospital Medicine Safety Consortium with antibiotic and diagnostic stewardship strategies at hospital discretion.Main Outcomes and MeasuresOverall improvement in ASB-related antibiotic use was estimated as change in percentage of patients treated with antibiotics who had ASB. Effect of diagnostic stewardship was estimated as change in percentage of patients with a positive urine culture who had ASB. Effect of antibiotic stewardship was estimated as change in percentage of patients with ASB who received antibiotics and antibiotic duration.ResultsOf the 14 572 patients with a positive urine culture included in the study (median [IQR] age, 75.8 [64.2-85.1] years; 70.5% female); 28.4% (n = 4134) had ASB, of whom 76.8% (n = 3175) received antibiotics. Over the study period, the percentage of patients treated with antibiotics who had ASB (overall ASB-related antibiotic use) declined from 29.1% (95% CI, 26.2%-32.2%) to 17.1% (95% CI, 14.3%-20.2%) (adjusted odds ratio [aOR], 0.94 per quarter; 95% CI, 0.92-0.96). The percentage of patients with a positive urine culture who had ASB (diagnostic stewardship metric) declined from 34.1% (95% CI, 31.0%-37.3%) to 22.5% (95% CI, 19.7%-25.6%) (aOR, 0.95 per quarter; 95% CI, 0.93-0.97). The percentage of patients with ASB who received antibiotics (antibiotic stewardship metric) remained stable, from 82.0% (95% CI, 77.7%-85.6%) to 76.3% (95% CI, 68.5%-82.6%) (aOR, 0.97 per quarter; 95% CI, 0.94-1.01), as did adjusted mean antibiotic duration, from 6.38 (95% CI, 6.00-6.78) days to 5.93 (95% CI, 5.54-6.35) days (adjusted incidence rate ratio, 0.99 per quarter; 95% CI, 0.99-1.00).Conclusions and RelevanceThis quality improvement study showed that over 3 years, ASB-related antibiotic use decreased and was associated with a decline in unnecessary urine cultures. Hospitals should prioritize reducing unnecessary urine cultures (ie, diagnostic stewardship) to reduce antibiotic treatment related to ASB.

Increasing Evidence That Diagnostic Stewardship May Improve Antibiotic Use

“…The best interventions include requiring appropriate indications for urine culture ordering and only performing urine cultures if the urine sample has pyuria, indicating inflammation. It is notable that in the study by Vaughn et al, relatively few defined approaches were used by hospitals, indicating the possibility of reducing antibiotic use for ASB far beyond the 34% relative reduction they noted.…”

“…This study provocatively frames findings in terms of favoring diagnostic over antimicrobial stewardship . A common goal of both forms of stewardship is improved antibiotic use and patient outcomes, and often staff from antimicrobial stewardship programs are those enacting diagnostic stewardship interventions.…”

“…2,3 Exposure to these unnecessary antibiotics can lead to patient adverse drug events and promotes antibiotic resistance.As reported in this issue of JAMA Internal Medicine, Vaughn and colleagues conducted a quality improvement initiative across 46 hospitals in the state of Michigan from 2017 to 2020 to address the problem of inappropriate antibiotic use for ASB. 4 They prospectively collected data on the prevalence of ASB at each hospital, shared data for benchmarking, shared best practices in antimicrobial and diagnostic stewardship, and, in 2018, selected treatment of ASB as a pay-for-performance metric. Hospitals then made individual decisions on how to best improve their practice.…”

“…5 It is notable that laboratorybased metrics are some of the few drivers to reduce overtesting and medical overuse. The study by Vaughn et al 4 focused on ASB, which was recently endorsed by the National Quality Forum as a metric of inappropriate diagnosis of UTI in hospitalized patients. 8 This metric will be one of the first to explicitly focus on limiting wrong diagnoses to limit unnecessary treatment with potential for greater improvement in testing.…”

“…In summary, Vaughn and colleagues 4 have completed a large, prospective evaluation of real-life quality improvement changes to address ASB, one of the primary drivers of unnecessary antibiotic use. They identified diagnostic stewardship changes to urine culturing as the most effective interventions to reduce antibiotic use for ASB.…”