Development and Validation of a Chinese Marital Intimacy Scale for Colorectal Cancer Survivors With an Ostomy (Ch-MIS-CRCO)

Background: Marital intimacy plays a significant role in patients’ quality of life. However, colorectal cancer (CRC) and ostomy surgery can disrupt this important aspect of life. Despite its significance, there is no specialized tool to assess marital intimacy in this population. Therefore, this study aims to develop and validate the Chinese Marital Intimacy Scale for CRC survivors with an ostomy (CRCO) (Ch-MIS-CRCO). Methods: An observational cross-sectional study was conducted following the instrument development procedures outlined by DeVellis, which include instrument formation and psychometric testing phase. Content validity was evaluated by content validity index (CVI), while construct validity was examined by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Convergent validity was assessed using correlations with the Lock and Wallace Marital Adjustment Test, Ostomy Adjustment Scale, and Stoma-QOL. Known-groups validity was evaluated across clinically relevant subgroups. Floor and ceiling effects were examined, and internal consistency reliability was assessed using Cronbach’s alpha. Results: The initial 52-item pool was refined through content validity assessment, pilot testing, item analysis, and EFA, resulting in a final 25-item scale across four dimensions, with eigenvalues ranging from 1.62 to 8.83, explaining 63.09% of the total variance. The scale demonstrated excellent model fit (χ²/df = 1.61; CFI = 0.95; TLI = 0.94; RMSEA = 0.05). Convergent validity was supported by significant correlations with the Lock and Wallace Marital Adjustment Test (r = 0.49), Ostomy Adjustment Scale (r = 0.55), and the Stoma-QOL (r = 0.59). Known-groups validity was confirmed, with higher scores observed among patients without ostomy complications, those with complete self-care ability, and those whose primary caregiver was their spouse (all p < 0.05). No floor or ceiling effects were detected. Internal consistency was high, with Cronbach’s α of 0.93 for the total scale and 0.85–0.90 for the subscales. Conclusion: The Ch-MIS-CRCO demonstrates strong psychometric properties and can be effectively used to evaluate marital intimacy among CRC survivors with an ostomy, further helping to predict and improve patients’ quality of life.