Disease burden morbidity assessment by self-report: Psychometric properties in older adults in Spain

Abstract

Aim: To carry out an analysis of the psychometric properties of the Disease Burden Morbidity Assessment (DBMA) according to the assumptions of the Classical Test Theory. Methods: A sample of 707 community-dwelling adults aged 65 years and older, living in Spain, completed the DBMA. Psychometric properties of the scale (feasibility, acceptability, scaling assumptions, reliability and construct validity) were analyzed. Results: The mean DBMA score was 6.8. Feasibility and acceptability were satisfactory, except for large floor effects (>50%), as well as a skewed distribution (1.8). Item-total corrected correlation ranged 0.10–0.49, item homogeneity index was 0.09 and Cronbach's alpha was 0.72. Disease burden correlated strongly with physical functioning (r = –0.56) and perceived health (r = –0.56), and moderately with depression (r = 0.41) and the Personal Wellbeing Index (r = –0.41). Exploratory factor analysis extracted five factors, explaining 44% of the variance. Conclusions: The DBMA is an acceptable and valid instrument for measuring disease burden in older adults. Future studies should include Rasch analysis to further assess dimensionality and explore other measurement properties.