Using the theory of planned behavior to assess factors that influence the intent to use human papillomavirus (HPV) vaccine among young adult college students
The aim of this study was i.) to determine the salient beliefs college students have regarding HPV vaccination and ii.) to determine college students’ intentions to be fully vaccinated against HPV within 12 months and factors that influence their intention. The theory of planned behavior (TPB) served as the theoretical framework to guide the study. The study assessed the significance of each of the TPB constructs – attitude, subjective norms, and perceived behavioral control – as well as additional constructs – knowledge and religiosity – in predicting behavioral intention. The relationships between demographic/personal factors and the study constructs were also assessed. A mixed-methods study design including qualitative and quantitative components, was applied. The study sample was comprised of a convenience sample of college students aged between 18 to 45 years attending a large public university in central Texas. For the qualitative portion, three focus group sessions were carried out to elicit the beliefs regarding HPV vaccination. Two investigators conducted a content analysis of the qualitative data and reached consensus on coding discrepancies. Twenty-four students participated in the focus groups, and a total of 45 beliefs were identified. Of these, 18 were salient, including 6 behavioral beliefs, 6 normative beliefs, and 6 control beliefs. For the quantitative portion, a web-based survey was developed using the TPB and information identified from the focus groups. The survey was administered via Qualtrics. Data analyses comprised descriptive, bivariate, and multivariate methods. Covariate adjusted linear regression models were used to assess association between intention and study constructs. Of 438 students who participated in the survey, there were 213 usable surveys. The initial model with attitude, subjective norms and perceived behavioral control as predictors accounted for about 40 percent of the variance in intention (R²= 0.4046, p<0.0001). Attitude (b=0.58, p<0.0001) and subjective norms (b=0.15, p=0.0372) were significant predictors of intention, while perceived behavioral control (b=0.01, p=0.8982) was not. Provider recommendation was the only significant covariate (b=1.15, p=0.0386). The additional constructs knowledge (R²= 0.4018, p=0.8179) and religiosity (R²= 0.4026, p=0.5808) did not significantly contribute to the model. Attitude and subjective norms differed by several demographic and personal factors, namely age, gender, race/ethnicity, provider recommendation, STD screening, sexual history, and vaccine experience. This study supports the use of the TPB in identifying college students’ beliefs regarding HPV vaccination, and in predicting intention to get fully vaccinated against HPV in the next 12 months. A focus on attitude, subjective norms and provider recommendation may be useful in developing more suitable interventions. Future studies are needed to assess other factors that may influence intention in larger or different college populations.