The burden of antimicrobial resistance: the case of escherichia coli

Abstract

Introduction: Antimicrobial resistance is considered a potential threat to global population health. National and international surveillance reports highlight the epidemiological burden of antibiotic resistant Escherichia coli, with particular reference to urinary tract infections (UTIs) and bacteraemia. Evidence on the health and cost burden of such infections in England is unknown; such evidence is needed to evaluate policies targeting antibiotic resistance and Gram-negative infections. Aim: The aim of this thesis was to estimate the burden of antibiotic resistant and susceptible E. coli infections in England, from the patient, healthcare system and labour productivity perspectives. Methods: The population of interest included adults in England with E. coli bacteraemia and/or UTIs. Cox proportional hazards, multistate and cohort simulation models were utilised to achieve the aim of the thesis. Data sources included national surveillance data, national hospital administrative data and published evidence. Results: It was estimated that antibiotic resistant and susceptible E. coli infections reduced annual, national health in 2015 (as measured by Quality-adjusted life years (QALYs)) by 303 QALYs and 1,136 QALYs, respectively. Though it was estimated that third-generation cephalosporin resistance and piperacillin/tazobactam resistance were individually associated with excess costs-per-case of over £300, antibiotic susceptible E. coli infections cost the NHS significantly more on an annual, national basis. The total societal cost (healthcare system and labour productivity costs combined) of E. coli UTIs and bacteraemia was estimated to be over £26.5 million in 2015. Conclusion: Both antibiotic resistant and susceptible E. coli infections cause a substantial burden to the English population, healthcare system and society. Investment in ‘infection prevention and control’ measures alongside antibiotic stewardship policy is required to alleviate this burden. Future research can apply the methods utilised in this thesis to other microbes, in other settings, to establish a robust evidence base regarding the burden of antimicrobial resistant and susceptible infections.