Development and Content Validation of a Belgian Patient Decision Aid for Surgical Decision-making in Rectal Cancer: A Double-modified Delphi Study.

Abstract

This study aimed to adapt an existing Canadian patient decision aid (PDA) for rectal cancer surgery to the Belgian healthcare context and to evaluate its content validity for patients considering low anterior resection (LAR) or abdominoperineal resection (APR). The PDA was updated through a literature review addressing surgical techniques and quality-of-life outcomes. Two modified Delphi studies, each comprising two rounds, were conducted in Belgium. Phase 1 included clinical and research experts and rectal cancer survivors from one university hospital. Phase 2 involved clinical and research experts from one university hospital and two general hospitals. Participants rated each PDA section for relevance, understandability, completeness, and correctness using a four-point Likert scale. Item-level and scale-level Content Validity Indices were calculated. The Belgian-adapted PDA comprised nine sections covering rectal cancer, surgical options, quality-of-life consequences, costs, and personal considerations. In both phases, the overall PDA achieved an S-CVI/Ave of at least 0.90 for relevance, understandability, completeness, and correctness. The cost section was revised following changes in Belgian ostomy reimbursement criteria. The Belgian-adapted PDA demonstrated satisfactory content validity within the participating Belgian panels. It is intended to complement professional counselling and support shared decision-making. Further research should evaluate its feasibility, implementation, and effects in clinical practice. Adaptation and local validation are required before use outside Belgium. In nurse-led clinics, clinical nurse specialists may use the PDA to structure discussions and support patients in considering surgical options in relation to their preferences and values.