Using Behavior Change Frameworks to Improve Healthcare Worker Influenza Vaccination Rates: A Systematic Review

"This review highlights that psychological theories of behavior change can help researchers, clinicians, and decision makers better understand HCW vaccination behavior, which may be used in turn to inform the development of evidence-based interventions."

The primary objective of this systematic review was to determine the effectiveness of interventions based on psychological frameworks of behavior change to improve healthcare worker (HCW) vaccination rates. The secondary objective was to determine which psychological frameworks have been used to predict HCW vaccination rates, including facilitators and barriers, as these may be used to develop and implement communication interventions in the future to improve vaccination rates.

There is a paucity of research examining theory-based interventions to increase influenza vaccination uptake: Of the 173 studies the researchers identified for full-text review, only 10 used behaviour change theories to predict HCW vaccination; no theory-based interventions were identified. The 10 peer-reviewed, primary data studies included in this review were conducted in Australia, Canada, Israel, Greece, the Netherlands, and the United States. The definition of HCW was found to be representative of staff in hospital care settings; however the majority of studies relied on HCW in nursing roles as participants. Self-reported influenza vaccination uptake was the primary outcome variable measured. The majority of studies examined HCW vaccination for seasonal influenza virus, although one study investigated pandemic (pH1N1) influenza vaccination.

The Health Belief Model (HBM) was the most common behavioural framework, applied in 60% of the studies identified. According to the HBM, HCW vaccination behaviour can be understood using 5 key constructs: (i) perceived susceptibility of self or others to influenza, (ii) perceived severity of influenza to self or others, (iii) perceived benefits of influenza vaccination for self or others, (iv) perceived barriers to influenza vaccination, and (v) cues to action (i.e., internal and external cues which are motivators for vaccine uptake). Variables from the perceived benefits category were frequently found to be significant predictors of vaccination; perceived susceptibility was the second most common HBM category used to predict HCW vaccination. Numerous cues to action items were also predictive of vaccination uptake. Knowledge of influenza vaccination recommendations and agreement with the content of vaccination guidelines predicted vaccination uptake, along with encouragement from supervisors and doctors. In addition, media attention and knowledge that individuals close to HCW feel vaccination is important were also predictors. In all studies, vaccinated HCW significantly differed from unvaccinated HCW on all HBM constructs evaluated. Vaccinated HCW were more likely to report that they were susceptible to influenza, that it was a serious disease, and had positive perceptions about the efficacy of influenza vaccination.

Two studies used the Theory of Planned Behavior (TPB), according to which intentions to perform a given behaviour are determined by attitudes (i.e., one's subjective evaluation of the behaviour and outcomes of the behaviour), subjective norms (i.e., one's assessments of whether close others would approve of the behaviour), and perceived behavioural control (i.e., one's assessment of whether one is ready and able to enact the behaviour). Attitude was found to be the strongest predictor of intention to get vaccinated, and intention to vaccinate was the strongest predictor of self-reported vaccination uptake. In one of the 2 studies (Cornally et al.), attitudes toward influenza vaccination, subjective norms, and perceived behavioural control were significantly correlated and explained 41.9% of the variance in intention to get vaccinated, with attitude and subjective norms emerging as the strongest contributors. Godin et al. extended TPB to include 4 additional variables: anticipated regret, moral norm, descriptive norm, and professional norm. This model correctly predicted 85% of HCW vaccination.

The other models the researchers investigated were Risk Perception Attitude (RPA) and the Triandis Model of Interpersonal Behavior. The RPA framework is based on the principles of Social Cognitive Theory and uses perceptions of risk to self and self-efficacy to understand how health information is used. Similarly, the Triandis Model of Interpersonal Behavior builds on The Theory of Planned Behavior. In this model, intention is influenced by cognitive factors (e.g., knowledge about vaccination), affective factors (e.g., one's attitudes about vaccination), and social factors (i.e., social norms related to the behaviour). The probability of HCW vaccination behaviour is influenced by intention and habit (e.g., past vaccination behaviour), which are both influenced by facilitating conditions (i.e., contexts that allow or provide reminders for a behaviour to be performed).

Five studies developed models to predict HCW vaccination using socio-demographic variables and constructs from a variety of behavioural theories. One study's multivariate model, combining sociodemographic, Health Belief Model (HBM), and Behavioral Intention Model (BIM, a precursor to the Theory of Planned Behavior) variables, correctly predicted 94% of self-reported HCW influenza vaccination. Another used sociodemographics, HBM, BIM, and the Attitudes and Self-Efficacy Model, which adds a measure of self-efficacy, to correctly predict 95% of HCW influenza vaccination uptake.

Considering that this review found that models developed using HBM constructs, along with other behavioural variables, were successful in predicting influenza vaccination uptake among HCW, the researchers say: "It is concerning that data supporting the use of behavior change frameworks (i.e. prediction of vaccination behavior) has not translated into uptake of research involving behavior change frameworks to design interventions to improve HCW vaccination behavior." Another reason that this dearth of theory-based work in the literature concerns the researchers relates to the observation that, while interventions to increase influenza vaccination uptake amongst HCW have historically focused on information and education, a large proportion of HCW continue to oppose vaccination regardless of facts, evidence, and information presented. This is due to the fact that "[k]nowledge is necessary but not sufficient to initiate behavior change....Vaccination is a complex behavior and must be understood in terms of the multi-factorial components, such as attitudes, beliefs, self-efficacy, motivation, perceived threat, and socio-cultural influences that are embodied in many other health behaviors."

In conclusion: "Our review has identified a number of theories that are effective at predicting actual vaccination uptake. Thus, future work should design interventions, implement, and evaluate interventions based on these theories."