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.