目的
長久以來，醫病雙方共同達成滿意且有品質的醫療決策，就是一個令人期待的重要目標。本研究欲瞭解剛被診斷為乳癌的女性患者在醫療決策中，是扮演主動或被動的角色及患者本身所參與的程度，並探討在醫病共享決策（Shared Decision Making, SDM）中，影響患者參與醫療決策的主要原因。

方法
研究對象為患有乳癌的台灣女性，填寫問卷當時以不超過其被診斷出乳癌的第60天為限。本文以質性與量化的混合型方法來分析問卷，採用「控制偏好量表」來評估受訪者參與醫療決策的程度。最後，本研究針對其中六人進行深度訪談，以瞭解影響患者決策模式的可能原因。

結果
接受問卷調查填寫者共包括111名女性乳癌患者。對於醫療決策中選擇主動、合作和被動角色者的比例分別為26.1％、44.2％和29.7％，而其中涉及了醫師與患者雙方都有共同參與的合作型SDM共有78.4％。另外，患者主要是信任醫師的專業而傾向被動角色，而選擇主動參與醫療決策的主因則是時間是否足夠與患者個人特質。

結論
多數受訪者在醫療決策中傾向選擇與醫師討論後再共同作決定，因此將SDM導入在乳癌醫療決策的過程是個非常可行且樂觀的方向。研究結果除了對乳癌患者之醫療決策模式能有進一步的瞭解之外，並可在臨床上醫病共享決策的推廣與實踐，提供重要的參考。

Purposes
It has long been an important and anticipated goal for both physicians and patients to reach satisfactory and high-quality medical decisions. The objective of this study was to understand whether female patients newly diagnosed with breast cancer played an active or passive role in medical decision-making. Additionally, the extent of their involvement and the main factors influencing patients' involvement in shared decision-making (SDM) were explored.

Methods
The participants were Taiwanese women who completed the study questionnaire within 60 days of their breast cancer diagnoses. Responses to the questionnaire were analyzed qualitatively and quantitatively using a mixed method approach. Further, the Control Preferences Scale (CPS) was adopted to assess the respondents’ degree of involvement in medical decision-making. In-depth interviews were conducted with six of the respondents to understand the possible reasons for patients’ decision-making patterns.

Results
A total of 111 female breast cancer patients participated in the survey. The proportions of respondents who chose active, collaborative, and passive roles in medical decision-making were 26.1%, 44.2%, and 29.7%, respectively. Among those interviewed, 78.4% collaborated in SDM involving both physicians and patients. Patients who tended to be passive in terms of SDM were so inclined mainly because of their trust in their physicians’ professionalism. Those who chose to actively participate in medical decision-making did so when they felt there was adequate time. Their personal characteristics were also factors influencing their participation.

Conclusions
Most respondents tended to discuss treatment options with their physicians before engaging in collaborative medical decision-making. Therefore, the incorporation of SDM into the breast cancer medical decision-making process is a highly feasible and optimistic approach. In addition to fostering a better understanding of the medical decision-making model for breast cancer patients, the results of this study also provide an important reference for the promotion and practice of SDM between physicians and patients in clinical practice.