Using The Theory Of Planned Behavior (TPB) To Investigate The Predictors Of Medication Adherence Behavior Among Hypertensive Patients

Objective:To investigate the personal characteristics and medication adherence behavior of thehypertensive patients in community, and to explore significant predictors of medicationadherence behavior based on the Theory of Planned Behavior.Methods:A questionnaire survey was conducted in convenience sampling community and subjects.Descriptive statistical methods were used to explore the personal characteristics,variables in TPB model, as well as medication adherence behavior of participants. Pathanalysis was used to explore personal characteristics’ effect on medication adherencebehavior. Structural equation model was used to explore the impact of latent variables ofTPB on medication adherence behavior, figuring out the most significant predictor ofmedication adherence behavior.Results:A total of396valid questionnaires are collected. The mean age of participants is66.47.55.1%of participants are female,72.5%received junior middle school education or more,9.8%of participants regularly drink，18.7%regularly smoke.53.8%are overweight orobese.55.8%are suffering from other disease such as diabetes, hyperlipidemia, coronaryheart disease and stroke. Mean duration of medication of participants is8.97.Result of path analysis indicates that combining with other disease exerts indirect effect on behavior through behavioral attitude. Attitude is more positive among patientscombined with other disease. Duration of medication exerts indirect effect on behaviorthrough impact on perceived behavioral control. Patients with longer duration ofmedication have stronger power of perceived behavioral control. Gender influencesbehavior through impact on behavioral intention. Compared with male, female patientshave stronger behavioral intention.The result of structural equation model shows that perceived behavioral control is themost important predictor of medication adherence behavior(standardized coefficient=0.545), which exerts both direct(standardized coefficient=0.47) and indirecteffect(standardized coefficient=0.075) on behavior. Behavioral attitude and subjectivenorms indirectly influence behavior through behavioral intention(standardized coefficient=0.135and0.081, respectively). Behavioral intention is moderator of other TPB variables,which exerts direct impact(standardized coefficient=0.30) on behavior. The Theory ofPlanned Behavior could account for50%of the variance in medication adherencebehavior.Conclusion:Result of this study indicates that perceived behavioral control is the key factor thataffects medication adherence behavior, followed by behavioral intention, attitude andsubjective norms. In order to improve patients’ medication adherence behavior,interventions to enhance perceived behavioral control should be the first priority.Innovation:This study used TPB combined with structural equation model to explore the correlationbetween variables in TPB for the first time, as well as predictors of medication adherencebehavior among hypertensive patients in community.