Rapid antibiotic susceptibility testing for urinary tract infections in secondary care in England: a cost-effectiveness analysis

Abstract

Objectives: To perform a model-based cost-effectiveness evaluation of a rapid antimicrobial susceptibility test.

Design: A Markov model of a cohort of hospital inpatients with urinary tract infection (with inpatient numbers based on national administrative data from 1 April 2017 to 31 March 2019).

Setting: Urinary tract infections (UTI) in acute National Health Service (NHS) Trusts in England, from the perspective of the NHS Healthcare system, at a national level.

Participants: A simulated cohort of approximately 280 000 non-pregnant adult inpatients within secondary care with a clinical suspicion of UTI.

Interventions: Evaluation of the implementation of a fast bacterial impedance cytometry test (BICT) compared with current practice.

Primary and secondary outcome measures: Incremental cost, quality-adjusted life years, net monetary benefit, and bed days and appropriateness of antibiotic use per patient. Costs are presented in 2022 GBP.

Results: Considering benefits arising from reduced time on inappropriate treatment, BICT gives an average net monetary benefit (NMB) over the simulation period of approximately £4.3 million and dominates culture methods (from the healthcare system perspective and with a willingness to pay threshold of £20 000 per quality-adjusted life year). Total inappropriate prescribing days due to the BICT test are reduced by 57%. The extent of the benefit from BICT implementation was strongly dependent on prevalence of resistance, with the NMB increasing sevenfold to over £30 million in a high (40%) resistance prevalence scenario. At the population level, the patient groups with the highest cost and quality-adjusted life year impacts were 65-100-year-old females, followed by males, with uncomplicated UTIs. At an individual patient level, however, 16-64-year-old females with complicated UTIs with oral treatment, followed by 65-100-year-old males with complicated UTIs with oral treatment, were impacted to the greatest degree by the rapid BICT.

Conclusions: Under conservative assumptions and for wide parameter sensitivity, the implementation of BICT would be cost-effective from the NHS healthcare system perspective.

Keywords: Diagnostic microbiology; HEALTH ECONOMICS; Urinary tract infections.