Association between ward-transfers and hospital-acquired infection: a study using routine data

Abstract

Abstract Ward-transfers have become more common as hospital staff balance patient needs with bed availability on specific wards. However, increased movement through the hospital may leave patients more vulnerable to potential infectious pathogen transmission routes via increased exposure to contaminated surfaces and more contacts with individuals. This may increase their risk of hospital-acquired infections (HAIs), an adverse event associated with greater antibiotic resistance, patient costs, morbidity, and mortality. This study aimed to quantify the association between the number of ward-transfers undergone during a hospital spell and the outcome of HAI. As elderly patients comprise a large proportion of hospital users and are a high-risk population for HAIs, analysis was focused on people over 65-years old. A retrospective case-control study was undertaken using data extracted from electronic health records and microbiology cultures of non-elective medical admissions to a London hospital trust between January 2016 and December 2018 (n = 24,439). Logistic regression was used to obtain the odds ratio for developing a HAI as a function of the number of ward-transfers until onset of HAI for cases, or hospital discharge for controls, while controlling for covariates including length of stay, procedures and comorbidities. Each additional ward-transfer increased the odds of developing a HAI by 8% (OR 1.08; 95%CI:1.04-1.12). The hospital is a complex environment, and interventions should be viewed in light of their impact on the system as a whole. These findings indicate that non-essential ward-transfers of elderly patients should be minimised. This may lower the incidence of infections in this population, potentially reduce the number of pathogen transmission routes in hospitals and alleviate staff burden incurred by ward-transfer associated procedures. Key messages We analysed 3 years of patient movement and microbiology data of elderly patients in a London hospital trust. Each ward-transfer increased the risk of developing a hospital-acquired infection by 8%. Reducing the number of non-essential ward-transfers patients undergo may lower the incidence of hospital-acquired infections; the decision to move a patient should therefore be carefully considered.