Predicting the use of complementary medicine: A test of the theories of reasoned action and planned behavior

The present study employed the theory of reasoned action (TRA) and its extension, the theory of planned behavior (TPB), to investigate the factors underlying intentions and actual use of homeopathy over a 1-month period. The study was prospective in design; 349 respondents completed a TPB questionnaire during the first phase of data collection, and 139 respondents were contacted (by telephone) in Phase 2 to provide information regarding their use of homeopathy. The findings provided support for the TPB as a predictor of intentions and use of homeopathy, and demonstrated that the model significantly enhanced the predictive utility of the TRA. Attitudes, subjective norms, and perceived control emerged as significant predictors of intention (R-2 = .49), while intention predicted behavior (R-2 = .56). In addition, past behavior significantly contributed to the prediction of intention and behavior.