Determinants of older adults' intentions to vaccinate against influenza: a theoretical application

Background: Despite many government initiatives, uptake of the trivalent influenza vaccine among the older adult population still remains suboptimal. If immunization rates are to be optimized, new approaches for identifying the determinants that facilitate or inhibit influenza vaccination decision making in this population are necessary. Methods: An extension of the theory of planned behaviour (TPB) provided the theoretical framework for the development of a multi-item questionnaire. One hundred and ninety-three white, independent living and city dwelling men (n = 77) and women (n = 116), completed the measure. The main outcomes of interest were future vaccination intentions. Results: Overall, the TPB predicted 48.2% of older adults' intentions to vaccinate next influenza season. Receiving the vaccine in the past and anticipating feelings of regret (the impact of missing a vaccination opportunity) contributed to increments of 10.7 and 13.7%, respectively, in explaining this intentional behaviour. Conclusion: Utility of theoretical frameworks is a useful resource tool for understanding the rationale behind the facilitating and inhibitory determinants of older adults' vaccination decision-making processes. The implications of this research are discussed with a view towards future directions for maximizing influenza vaccination uptake initiatives using theoretically driven applications.