Objectives Renal replacement therapy (RRT) is increasingly adopted for critically ill patients diagnosed with acute kidney injury, but the optimal time for initiation remains unclear and prognosis is uncertain, leading to medical complexity, ethical conflicts, and decision dilemmas in intensive care unit (ICU) settings. This study aimed to develop a decision aid (DA) for the family surrogate of critically ill patients to support their engagement in shared decision-making process with clinicians.
Methods Development of DA employed a systematic process with user-centered design (UCD) principle, which included: (i) competitive analysis: searched, screened, and assessed the existing DAs to gather insights for design strategies, developmental techniques, and functionalities; (ii) user needs assessment: interviewed family surrogates in our hospital to explore target user group's decision-making experience and identify their unmet needs; (iii) evidence syntheses: integrate latest clinical evidence and pertinent information to inform the content development of DA.
Results The competitive analysis included 16 relevant DAs, from which we derived valuable insights using existing resources. User decision needs were explored among a cohort of 15 family surrogates, revealing four thematic issues in decision-making, including stuck into dilemmas, sense of uncertainty, limited capacity, and delayed decision confirmation. A total of 27 articles were included for evidence syntheses. Relevant decision-making knowledge on disease and treatment, as delineated in the literature sourced from decision support system or clinical guidelines, were formatted as the foundational knowledge base. Twenty-one items of evidence were extracted and integrated into the content panels of benefits and risks of RRT, possible outcomes, and reasons to choose. The DA was drafted into a web-based phototype using the elements of UCD. This platform could guide users in their preparation of decision-making through a sequential four-step process: identifying treatment options, weighing the benefits and risks, clarifying personal preferences and values, and formulating a schedule for formal shared decision-making with clinicians.
Conclusions We developed a rapid prototype of DA tailored for family surrogate decision makers of critically ill patients in need of RRT in ICU setting. Future studies are needed to evaluate its usability, feasibility, and clinical effects of this intervention.

Key words: decision aids, renal replacement therapy, intensive care units, shared decision-making, user-centered design, surrogate