背景：加護病房疾病嚴重度與死亡率高，家屬時常面臨替代重症病患決定是否繼續醫療處置、或接受安寧緩和療護困境。目的：探討重症病患決策代理人的醫療決策行為意向及其相關因素。方法：採橫斷式相關性研究設計，於南部某醫學中心之6個加護病房進行收案，共收案193位決策代理人。使用三份結構式問卷，含基本資料、家庭關係量表及醫療決策行為意向量表。結果：決策代理人之醫療決策行為意向與「與重症病患的關係」（Eta=.343, p=.020）、「重症病患年齡」（r=.295, p<.01）、「重症病患有無預立遺囑」（Eta=.223, p=.002）呈現顯著正相關；與「重症病患住院天數」（r=-.263, p<.01）呈現顯著負相關。重症病患年齡、重症病患有無預立遺囑、重症病患住院天數為決策代理人醫療決策行為意向之預測因子，共可解釋的變異數13.9%。結論：實務應用醫護人員評估決策代理人醫療決策行為意向時，須考量代理人與重症病患的關係，分析重症病患年齡、住院天數、有無預立遺囑對代理人的影響，以協助重症病患達最大利益的醫療照護。
Background: The severity of diseases and high mortality rates that typify the intensive care unit often make it difficult for surrogate decision makers to make decisions for critically ill patients regarding whether to continue medical treatments or to accept palliative care. Purpose: To explore the behavioral intentions that underlie the medical decisions of surrogate decision makers of critically ill patients and the related factors. Methods: A cross-sectional, correlation study design was used. A total of 193 surrogate decision makers from six ICUs in a medical center in southern Taiwan were enrolled as participants. Three structured questionnaires were used, including a demographic datasheet, the Family Relationship Scale, and the Behavioral Intention of Medical Decisions Scale. Results: Significantly positive correlations were found between the behavioral intentions underlying medical decisions and the following variables: the relationship of the participant to the patient (Eta = .343, p = .020), the age of the patient (r = .295, p < .01), and whether the patient had signed a currently valid advance healthcare directive (Eta = .223, p = .002). Furthermore, a significantly negative correlation was found between these intentions and length of stay in the ICU (r = -.263, p < .01). Patient age, whether the patient had signed a currently valid advance healthcare directive, and length of stay in the ICU were all predictive factors for the behavioral intentions underlying the medical decisions of the surrogate decision makers, explaining 13.9% of the total variance. Conclusions/Implications for Practice: In assessing the behavioral intentions underlying the medical decisions of surrogate decision makers, health providers should consider the relationship between critical patients and their surrogate decision makers, patient age, the length of ICU stay, and whether the patient has a pre-signed advance healthcare directive in order to maximize the effectiveness of medical care provided to critically ill patients.