Influencing Factors of Generic Prescribing Behavior of Physicians: A Structural Equation Model Based on the Theory of Planned Behavior.

Background: Although affordable generics could probably contribute to the solution of rapidly increasing pharmaceutical expenditure, those drugs are prescribed at a lower rate in China. Physicians' perception and knowledge of generics have a great influence on their prescribing behavior. Objective: This study aimed to identify factors that affect physicians' generic prescribing behavior based on the theory of planned behaviors (TPB). Methods: Data were collected by both electronic and paper-based surveys from 1297 Chinese physicians, and 1047 surveys were retained. The structural equation model (SEM) was employed to investigate the relationship between four behavioral constructs, namely, attitudes, subjective norms, perceived control of behaviors, and intentions. Results: About 50% of Chinese physicians had a positive attitude towards generic drugs that had passed the "Consistency Evaluation of Quality and Efficacy of Generic Drugs" (high-quality generic drugs), but their knowledge of generic drugs was relatively inadequate. The path coefficients for the effect of attitudes, subjective norms, and perceived behavioral control on behavioral intention were 0.285, 0.366, and 0.322 respectively. The path coefficients for the effect of behavioral intention and perceived behavioral control on prescribing behavior were 0.009 and 0.410 respectively. Conclusion: Physicians' attitudes, subjective norms, and perceived behavioral control were significant positive correlation predictors of behavioral intention. Subjective norms and perceived behavior control had a greater impact than attitude on physicians' prescribing intention. However, the generic prescribing behavior is not under the volitional control of Chinese physicians. Physicians' prescribing practice is likely affected by perceived strong control over prescribing generic drugs.