Background <p>A conceptually guided framework examining how family communication relates to advance directive completion rates among older adults may offer useful insights for improving end-of-life decision-making in aging societies. However, persistent inconsistencies across studies remain unresolved, coupled with limited mechanistic explanations.</p> Method <p>The data are derived from a field survey project conducted in August 2023, targeting older adults residing in a public elder care institution in Hangzhou, China. This project collected data from 571 participants regarding their inclination toward death taboo, attitudes toward advance directives, and decisions on advance directive formulation. Moderation modeling and marginal analysis are employed to examine the relationships among family communication, death taboo, and advance directive completion.</p> Results <p>A total of 25.09% of participants report avoiding discussions about death in family settings, while 57.27% perceive advance directives as beneficial, and 21.72% formulate a personal advance directive. Family communication is associated with an 11.44% higher probability of advance directive completion, whereas death taboo shows a significant interaction effect, with the positive association attenuated at higher levels of death taboo.</p> Conclusion <p>This study suggests that higher levels of death taboo are associated with a weaker relationship between family communication and advance directive completion. We interpret this pattern cautiously within a family protectionism framework, where death taboo may reflect protective information shielding within family networks and may also be linked to a “fear-of-fear” dynamic.</p>