Influenza vaccination for healthcare workers who care for people aged 60 or older living in long‐term care institutions

Background A systematic review found that 3% of working adults who had received influenza vaccine and 5% of those who were unvaccinated had laboratory‐proven influenza per season; in healthcare workers (HCWs) these percentages were 5% and 8% respectively. Healthcare workers may transmit influenza to patients. Objectives To identify all randomised controlled trials (RCTs) and non‐RCTs assessing the effects of vaccinating healthcare workers on the incidence of laboratory‐proven influenza, pneumonia, death from pneumonia and admission to hospital for respiratory illness in those aged 60 years or older resident in long‐term care institutions (LTCIs). Search methods We searched CENTRAL (2015, Issue 9), MEDLINE (1966 to October week 3, 2015), EMBASE (1974 to October 2015) and Web of Science (2006 to October 2015), but Biological s only from 1969 to March 2013 and Science Citation Index‐Expanded from 1974 to March 2013 due to lack of institutional access in 2015. Selection criteria Randomised controlled trials (RCTs) and non‐RCTs of influenza vaccination of healthcare workers caring for individuals aged 60 years or older in LTCIs and the incidence of laboratory‐proven influenza and its complications (lower respiratory tract infection, or hospitalisation or death due to lower respiratory tract infection) in individuals aged 60 years or older in LTCIs. Data collection and analysis Two authors independently extracted data and assessed risk of bias. Effects on dichotomous outcomes were measured as risk differences (RDs) with 95% confidence intervals (CIs). We assessed the quality of evidence with GRADE. Main results We identified four cluster‐RCTs and one cohort study (n = 12,742) of influenza vaccination for HCWs caring for individuals ≥ 60 years in LTCIs. Four cluster RCTs (5896 residents) provided outcome data that addressed the objectives of our review. The studies were comparable in their study populations, intervention and outcome measures. The studies did not report adverse events. The principal sources of bias in the studies related to attrition, lack of blinding, contamination in the control groups and low rates of vaccination coverage in the intervention arms, leading us to downgrade the quality of evidence for all outcomes due to serious risk of bias. Offering influenza vaccination to HCWs based in long term care homes may have little or no effect on the number of residents who develop laboratory‐proven influenza compared with those living in care homes wh