The Chinese Mandarin COMHON Index and Braden Scale to assess pressure injury risk in intensive care: An inter-rater reliability and convergent validity study

Background: The COMHON Index is an intensive-care-specific pressure injury risk assessment tool, which has demonstrated promising psychometric properties. It has been translated into Chinese Mandarin but requires inter-rater reliability testing and comparison to the standard care instrument (Braden Scale) before clinical use. Objectives: This study aimed to test and compare the inter-rater reliability and convergent validity of the Chinese Mandarin versions of the COMHON Index and Braden Scale. Methods: The study was conducted in a Chinese comprehensive intensive care unit. Based on a sample size calculation, five registered nurse raters with at least 6-months experience independently conducted risk assessments for 20 adult patients using both the COMHON Index and Braden Scale. Intraclass correlations (ICC) for inter-rater reliability, standard errors of measurement (SEM), and minimally detectable change (MDC) were calculated. Convergent validity was assessed using Pearson Product Moment Correlation for sum scores and Spearman's rho for subscales. Results: Inter-rater reliability of COMHON Index and Braden Scale sum scores was very high (ICC [1,1] = 0.973; [95% confidence interval 0.949–0.988]; SEM 0.54; MDC 1.50) and high (ICC [1,1] = 0.891; [95% confidence interval 0.793-0.951]; SEM 0.93; MDC 2.57), respectively. All COMHON-Index subscales demonstrated ICC values >0.6, whereas two Braden Scale subscales (Mobility, Activity) were below this threshold. Instrument sum scores were strongly correlated (Pearson's r = −0.76 [r² = 0.58]; p < 0.001), as were three subscale item pairs (mobility r_s = −0.56 [r² = 0.32]; nutrition r_s = −0.63 [r² = 0.39]; level of consciousness/sensory perception r_s = −0.67 [r² = 0.45] p < 0.001). Conclusion: Both the COMHON Index and Braden Scale demonstrated high levels of inter-rater reliability and measured similar constructs. However, the COMHON Index demonstrated superior inter-rater reliability and the results suggest that it better detects changes in patient condition and subsequently pressure injury risk. Further testing is recommended.