The Bariatric Surgery Motivation Questionnaire: A Validated Tool for Preoperative Assessment in Persian Population

Introduction: Bariatric surgery represents a highly effective intervention for individuals with severe obesity, yet the preoperative motivational factors influencing adherence and long-term outcomes remain insufficiently explored, particularly in the context of mental health. This study aimed to develop and validate a culturally tailored questionnaire to assess preoperative motivations among bariatric surgery candidates, thereby enhancing personalized care. Methods: A mixed-methods study conducted from 2017 to 2019 at Rasool-e-Akram Hospital, Tehran, Iran, enrolled 448 adults with severe obesity (BMI ≥ 40 kg/m² or ≥35 kg/m² with at least one comorbidity) . Semi-structured interviews (n=200) generated an initial 158-item pool, which was refined into a 94-item pilot questionnaire (n=100) and subsequently a final 30-item version (n=148). The validation process encompassed evaluations of content validity (via Content Validity Ratio [CVR] and Content Validity Index [CVI]), construct validity (through Exploratory Factor Analysis [EFA]), reliability (using Cronbach’s alpha), and convergent/divergent validity (employing the Treatment Self-Regulation Questionnaire [TSRQ] and Patient Health Questionnaire-9 [PHQ-9]). Results: The 30-item Bariatric Surgery Motivation Questionnaire encompasses four domains: Health (8 items), Physical Discomfort (4 items), Psychosocial Factors (12 items), and Attitudes Toward Surgery (6 items). EFA confirmed the factorial structure, accounting for 63.4% of variance (KMO=0.739, p<0.001). Content validity was strong (S-CVI/Ave=0.87; CVR>0.49). Overall reliability was satisfactory (α=0.813), with domain-specific alphas ranging from 0.312 to 0.807. Convergent validity with TSRQ (r=0.78, p<0.001) and divergent validity with PHQ-9 (r=-0.02, p=0.032) were supported. Conclusion: The Bariatric Surgery Motivation Questionnaire is a potentially valid and reliable instrument for evaluating preoperative motivations among bariatric surgery candidates. It provides clinicians with a practical means to identify motivational factors that may affect surgical outcomes. Further refinement of domains with lower reliability and validation in larger multicenter samples could enhance its clinical utility.