Rehospitalizations due to major adverse cardiac events (MACE) could be substantially reduced by vaccinating patients admitted for acute coronary syndrome (ACS) for influenza prior to discharge, according to a study published in PLOS One. Furthermore, achieving an influenza vaccination rate of at least 80% could be cost-saving.
Despite evidence that influenza vaccination can reduce the incidence of MACE in patients with existing cardiovascular disease, vaccine coverage in the 2015 to 2016 US influenza season for individuals with heart disease was only 48%. To estimate the cost-effectiveness of increasing influenza vaccination with the goal of preventing readmissions due to MACE, the study investigators built a Monte Carlo (probabilistic) spreadsheet-based decision tree based on current (2018) vaccination coverage of the estimated 493,750 US patients with ACS from the healthcare payer perspective. Time lost from work and outpatient costs were excluded, and only vaccination and hospitalization costs were included. Also estimated were the incremental cost/MACE case averted and incremental cost/quality-adjusted life years (QALY) gained (incremental cost-effectiveness) if 75% of hospitalized patients with ACS were vaccinated by discharge and the impact of increasing vaccination coverage incrementally by 5% up to 95% in a sensitivity analysis. Analyses focused on hospitalized adults aged 65 years or older and those aged 18 to 64 years, with varying vaccine effectiveness from 30% to 40%.
At 75% influenza vaccine coverage by hospital discharge, vaccination was cost-saving from the healthcare payer perspective in adults aged 65 years or older. The incremental cost-effectiveness was $12,680/QALY (95% CI, 6273-20,264) in adults 18 to 64 years and $2,400 (95% CI, -1992 to 7398) in all adults aged 18 years or older.
This resulted in approximately 500 (95% CI, 439-625) additional averted MACEs per year for all adult patients aged 18 years or older and added approximately 700 (95% CI, 578-825) QALYs. After approximately 80% vaccination, vaccination in adults aged 18 or older becomes cost-saving.
An additional cost of $3 million is required to achieve a 75% vaccination rate in this population. Overall, the cost of vaccination, vaccine effectiveness, and rate of vaccination coverage had the most impact on results.
The study investigators concluded, “All medical providers of patients with cardiovascular disease, including pharmacists, have a role in assessing patients’ vaccination status at each clinical encounter, including hospital discharge, providing a clear recommendation for influenza vaccination, and offering influenza vaccination and other vaccines as indicated. Medical primary care providers, specialty providers, and other vaccine providers, including pharmacists, could prevent MACEs during the influenza season by stocking influenza vaccines and recommending influenza vaccination for all adult patients with [cardiovascular disease] each year.”
Peasah SK, Meltzer MI, Vu M, Moulia DL, Bridges CB. Cost-effectiveness of increased influenza vaccination uptake against readmissions of major adverse cardiac events in the US [published online April 29, 2019]. PLoS One. doi:10.1371/journal.pone.0213499