Psychometric Properties and Hidden Dimensionality of the Sinhala Version of End Stage Renal Disease Adherence Questionnaire (SINESRD-AQ) Among Patients Receiving Haemodialysis in a Selected Hospital in Sri Lanka

Abstract Objective The purpose of this study was to evaluate the psychometric properties of Sinhala translated version of End Stage Renal Disease Adherence Questionnaire (SINESRD-AQ). Results A total of 150 patients with mean age of 54.08±10.78 (±SD) years were included. Majority were males (72.7%). Excellent face and content validity of SINESRD-AQ was reported with an average I-CVI of 0.93. The Confirmatory Factor Analysis of two subscales of ESRD-AQ demonstrated barely acceptable model fit (SRMR=0.120, CFI=0.913, GFI=0.997, AGFI=0.996, NNFI=0.896). Subsequent Non-linear Principal Component Analysis (CATPCA), O’Connor parallel analysis and Cattell’s Scree plot revealed new dimensionality with five components of SINESRD-AQ explaining 74% of the total variance. Acceptable level of Cronbach’s Alpha and composite reliability confirmed the internal consistency reliability of new dimensionality. Convergent validity of new dimensionality was confirmed with Composite Reliability (CR) and Average Variance Extracted (AVE) with the values greater than 0.7 and 0.5 respectively. According to the Fornell Larcker criterion (1971), the square root of AVEs of components were greater than the inter component correlations and heterotrait-monotrait values were less than the threshold of 0.85 demonstrated the discriminant validity of new dimensionality.