Development of A Quality of Life Assessment Scale in Patients with Inflammatory Bowel Disease

Abstract

Aims: This study aimed to develop a scale for quality of life (QOL) assessment in patients with inflammatory bowel disease.

Methods: Based on the results of our previous exploratory studies on factors associated with QOL, a survey was conducted among outpatients in two hospitals using a questionnaire. Reliability of the scale was verified by Cronbach’s coefficient alpha and retesting, construct validity by factor analysis, and criterion-related validity by correlation coefficient with the external criterion.

Results: A total of 460 questionnaires were distributed, and 319 participants (222 patients with Crohn’s disease and 97 patients with ulcerative colitis) were analyzed (69.3% effective response rate). Using item analysis and exploratory factor analysis, 19 items and five factors were extracted. Cronbach’s coefficient alpha for 300 participants with no missing values for the 19 items was .914, and it was within the range of .710 to .927 by factor. The intraclass correlation coefficient of retesting was .820. The correlation coefficient with the external criterion was .388 for the physical component summary and .711 for the mental component summary of the short-form 8. It was .731 for the 10-point scale life satisfaction ratings.

Conclusion: The results showed that overall reliability and validity of the scale were good; however, there were still unresolved issues with construct validity.