Australian preferences for influenza vaccine attributes and cost: A discrete choice experiment.

Abstract

People in Australia have access to different influenza vaccines, but may be unaware of their options and features. Preference studies for differentiated influenza vaccines including cell-based vaccines are limited, particularly in Australia. This study investigated which influenza vaccine attributes people in Australia value using a discrete choice experiment (DCE). Adults in Australia ineligible for free influenza vaccines had been vaccinated in the last 5 years and intended to be vaccinated again completed an online survey. Participants (N = 1203) were presented three influenza vaccine profiles described by eight attributes. Half the DCE scenarios described influenza season severity to be the same as last year, and the other half as more severe. DCE data were analyzed using a mixed multinomial logit (MMNL) model. All eight attributes significantly predicted vaccine choice (p < .05). Regardless of influenza season severity, participants preferred a vaccine: with greater protection, designed to be an exact match to circulating strains (match), using modern technology, manufactured by an Australian company, available at pharmacies, preferred by health care professionals (HCP), government funded for high-risk individuals and having lower cost. The top three attributes by importance were protection, match and cost. Participants were willing to pay more for match and higher protection. The Marginal Willingness to Pay (MWTP) for the most important attributes, excluding cost, were AUD $1.61/$2.18 for each additional percent in protection (same/more severe season), AUD $25.37/$32.37 for match and AUD $4.06/$15.97 for HCP preference. Findings indicate that match, protection, cost and HCP preference are key to vaccine choice, highlighting the importance of shared decision-making.