Reproducibility, longitudinal validity and interpretability of the Disease Burden Morbidity assessment in people with chronic disease

Objective: To evaluate the reproducibility, longitudinal validity, and interpretability of the disease burden morbidity assessment in people with chronic conditions including multimorbidity. Methods: The study was conducted using a longitudinal cohort design. A large consecutive sample of adult patients at an Australian community-based rehabilitation service was included with testing at baseline and three-month follow-up (testing longitudinal validity and interpretability). A smaller subsample of patients completed a one-week test–retest (testing reproducibility). Outcome measures included the Disease Burden Morbidity Assessment and 36-item Short-Form Health Survey. Participants in the study received tailored, interdisciplinary intervention between baseline, and three-month follow-up but did not typically receive intervention between baseline and retest. Results: The longitudinal validity and interpretability sample included 351 participants and the reproducibility sample included 56 participants. Longitudinal validity and interpretability were generally supported with hypotheses supported or partly supported and a small percentage of lowest total scores for impact on daily activities (0.6% at baseline, 1.3% at three-month follow-up). Reproducibility parameters were acceptable for the total score measuring impact on daily activities (e.g. ICC = 0.76). Discussion: Reproducibility, longitudinal validity, and interpretability of the disease burden morbidity assessment were generally supported for community-based chronic disease patients.