計劃行為理論已運用至研究多種健康行為的執行，但尚未用以探討台灣各種不同診斷慢性病患者的健康行為。有鑑於此，本研究採質性設計，以36位不同診斷的慢性病患者為研究對象，確認出計劃行為理論各建構的決定因子，以作為日後量性研究的擬訂量測指標。將逐字稿做內容分析後，發現慢性病患者在執行健康行為所持態度的決定因子為優點與缺點；影響健康行為執行的重要他人為家人、社會網絡、及健康專業人士；所感知行為控制的決定性因子則為有助及阻礙健康行為執行者。對於以計劃行為理論來探究慢性病患者的健康行為，本研究結果提供了一個新的視野。

The theory of planned behavior (TPB) has been successfully applied to various health behaviors. Previous research using this theory has not described the health behaviors of Taiwanese people diagnosed with various different chronic illnesses. Because TPB constructs and determinants are abstract, qualitative interviews were conducted with 36 people with various chronic illness diagnoses to identify such determinants and establish measurement indicators for further quantitative study. Content analysis of responses identified the determinants of attitude affecting adoption of health behaviors, both in terms of encouraging and discouraging adoption. The major referents that influenced health behavior adoption included family members, social networks, and health professionals. The determinants of perceived behavioral control included making health behavior easy and hindering health behavior. These findings provide a new glimpse into the application of the theory of planned behavior on the health behavior of the chronically ill population.