Assessing the predictive validity of psychosocial factors on influenza vaccine acceptance among health care workers : a multi-study design

Abstract

Seasonal influenza vaccination of Health Care Workers (HCWs) is the most effective method to protect staff and patients during influenza epidemics. Although Canadian provincial and territorial governments offer a publically funded influenza vaccine to all individuals working in and around the healthcare sector, vaccine uptake is remarkably low. This dissertation follows a multi-year multi-study initiative targeting HCW vaccine uptake.

In Study 1, a novel Theory of Planned Behaviour (TPB) intervention was created and tested to determine if the presence of a unit champion had a positive impact on seasonal influenza vaccine uptake among a HCW population. The results of Study 1 suggest tailored interventions, such as the peer champion process, are effective at increasing HCW vaccination rates. A call for further examination into the utility of psychosocial predictors is made.

Study 2 was designed to determine which elements of a modified TPB framework were predictive of HCW's intentions to receive seasonal influenza vaccine. Results partially support the use of a modified TPB, over and above a measure of past behaviour, when predicting HCW influenza vaccination. HCW's attitudes toward seasonal influenza vaccination were a strong and significant predictor of intentions to receive vaccine. The relative strength of normative influences such as moral responsibility and estimated vaccine uptake of peers are explored as potential additions to the subjective norm factor.

Study 3 tested the adequacy of the TPB in explaining intention to receive vaccine including a modified PBC item set, tested the predictive ability of intention to receive vaccine on actual vaccine uptake, and attempted to replicate the findings of Study 2. Results show that past behaviour was able to account for a small but significant increase in intentions to receive vaccine; however, past behaviour was not able to account for additional variance in vaccine uptake. The predictive strength of attitudes toward seasonal influenza vaccine was replicated.

A general discussion synthesizes the findings from studies 1, 2 and 3. The adequacy of an extended TPB model to predict seasonal influenza vaccine among a HCW population is examined and a call for tailored interventions is made. Limitations and future research activities are discussed.