Background: Despite the extensive literature on facilitating advance care planning (ACP) with patients with serious illnesses, opportunities to include surrogates or family caregivers are overlooked. The research objective was to examine whether previous medical decision-making involvement for a loved one is associated with one's own ACP conversations with family and the potential mediating effect of knowledge of a loved one's end-of-life treatment preferences. Methods: This study employed a cross-sectional design using data from the 2016 Kaiser Family Foundation/The Economist Four-Country Survey on Aging and End-of-Life Medical Care. The sample included 627 US adults who completed the survey and were involved in making medical decisions for a loved one in the past. Multiple binary logistic regression and linear regression models were established for mediation analyses. Results: Participants in our nationally derived sample were largely confident in their knowledge of a deceased loved one's end-of-life treatment preferences. 66.8% of the sample had ACP conversations with family. The involvement in a loved one's medical decision making was significantly associated with higher odds of having ACP conversations with family (OR = 1.93, P = .01), but this relationship was significantly mediated by knowledge of one's end-of-life treatment preferences (b = .31, Boot CI = .12-.49). Conclusions: Previous experience in making medical decisions for a loved one may facilitate one's own ACP behavior through knowing a loved one's end-of-life treatment preferences. Clinicians in end-of-life settings are uniquely positioned to engage family members who were involved in medical decision-making for others before in ACP.
Keywords: advance care planning; end of life; knowledge of treatment preferences; mediation; medical decision making.