Structural equation modeling for implementation intentions, cancer worry, and stages of mammography adoption

Objectives This study aimed to develop a structural model for mammography adoption in Japanese middle-aged women by using constructs from the transtheoretical model (TTM), the theory of planned behavior (TPB), implementation intentions, and cancer worry. Methods Questionnaires based on items including TTM, TPB, implementation intentions, cancer worry-related variables, and demographic variables were distributed to 1000 adult women aged 40 to 59 years, with 641 subjects being used in the final analysis (response rate = 64.1%). Results Regarding the stage of adoption, 79 participants (12.3%) were at the precontemplation stage, 30 (4.7%) were at the relapse stage, 142 (22.2%) were at the contemplation stage, 88 (13.7%) were at the action stage, and 302 (47.1%) were at the maintenance stage. Our model, derived from structural equation modeling, revealed that the stage of mammography adoption was significantly affected by goal intentions, implementation intentions, perceived barriers, history of breast cancer screening, and relative risk. A logistic regression analysis revealed that goal intentions and implementation intentions significantly predicted mammography uptake within 1 year. Conclusion This study developed an integrated model constructed from TTM, TPB, implementation intentions, and cancer worry to account for mammography adoption in Japan, and also confirmed the predictive validity of the model.