RESUMEN
BACKGROUND: Influenza vaccination has been clinically shown to reduce adverse cardiovascular outcomes in acute coronary syndrome (ACS) patients, but the economic perspectives can provide important data to make informed decisions. This study aimed to perform the economic evaluation of lifelong annual influenza vaccination for cardiovascular events and well-established pneumonia prevention. METHODS: Lifetime costs, life-expectancy, and quality-adjusted live years (QALYs) were estimated beyond one-year cycle length of a six-health states Markov model condition on whether a hospitalization for ACS, stroke, heart failure, pneumonia, no hospitalizations occurred, or death. The comparison of three age-groups of 40-49, 50-65, and > 65 years scenario was performed. Incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB) were presented as a societal perspective in 2016. The model robustness was determined by one-way and probabilistic sensitivity analyses. RESULTS: The influenza vaccination was cost-effective in all age-groups, by dominant ICERs (lower cost with higher effectiveness) which was completely lower than acceptable willingness-to-pay threshold of Thailand [160,000 THB (4,466.8 USD) per QALYs], with a great incremental value of NMB. Especially, the 50-year-old-and-above scenario was shown as the most benefit at 129,092 THB (3,603.9 USD) for each patient. CONCLUSIONS: The annually additional influenza vaccination to standard treatment in ACS was cost-effective in all age-groups, which should be considered in clinical practice and health-policy making process.
RESUMEN
Introduction. The prognosis of acute coronary syndrome (ACS) patients has been improved with several treatments such as antithrombotics, beta-blockers, and angiotensin-converting enzyme inhibitors (ACEI) as well as coronary revascularization. Influenza vaccination has been shown to reduce adverse outcomes in ACS, but no information exists regarding the interaction of other treatments. Methods. This study included 439 ACS patients from Phrommintikul et al. A single dose of inactivated influenza vaccine was given by intramuscular injection in the vaccination group. The cardiovascular outcomes were described as major cardiovascular events (MACEs) which included mortality, hospitalization due to ACS, and hospitalization due to heart failure (HF). The stratified and multivariable Cox's regression analysis was performed. Results. The stratified Cox's analysis by influenza vaccination for each cardiovascular outcome and discrimination of hazard ratios showed that beta-blockers had an interaction with influenza vaccination. Moreover, the multivariable hazard ratios disclosed that influenza vaccine is associated with a significant reduction of hospitalization due to HF in patients who received beta-blockers (HR = 0.05, 95% CI = 0.004-0.71, P = 0.027), after being adjusted for prognostic indicators (sex, dyslipidemia, serum creatinine, and left ventricular ejection fraction). Conclusions. The influenza vaccine was shown to significantly modify the effect of beta-blockers in ACS patients and to reduce the hospitalization due to HF. However, further study of a larger population and benefits to HF patients should be investigated.