In-depth psychometric evaluation of the PsychQOL questionnaire: factor structure and ROC analysis

Abstract

Validated quality of life assessments that show strong structural validity and screening utility with a cut-off point for psychiatric patients remain scarce. The initial validation of the New Psychological Quality of Life (PsychQOL) revealed a five-factor model through Exploratory Factor Analysis (EFA). This study aimed to assess the construct validity of the New Psychological Quality of Life (PsychQOL) measure through Confirmatory Factor Analysis (CFA) and Receiver Operating Characteristic (ROC) curve analysis, and to establish the preliminary cut-off score that differentiates those with and without psychiatric disorders. A total of 571 participants (334 healthy adults and 237 psychiatric patients) were recruited face-to-face and via online platforms for this cross-sectional study. Participants provided demographic information and completed the PsychQOL questionnaire. CFA of the final model showed acceptable fit in both samples after two items were removed. Multigroup CFA was conducted to test measurement invariance. Configural and metric invariance were supported, while scalar invariance was not fully established. The final Cronbach’s α for the 22- item questionnaire was 0.95. The ROC curve analysis yielded the AUC value of 0.83, p  < 0.001, 95% CI = 0.80–0.87, suggesting that the questionnaire demonstrated an acceptable ability to distinguish those with and without psychiatric disorders. Overall, PsychQOL exhibits good reliability and acceptable construct validity, along with a preliminary cut-off point for distinguishing psychiatric from non- psychiatric populations.