Objective: Depression is associated with poor outcomes among older adults with asthma, and the presence of multiple comorbidities may magnify this relationship. We sought to determine the association of comorbidities with depressive symptoms among older adults with asthma.
Methods: Secondary analysis of data from a randomized controlled trial of older adults with poorly controlled asthma and comorbidities. Comorbidities were measured in two ways: (1) as a count of all the patient's chronic diseases, and (2) as a count of chronic illnesses with self-management intensive needs (diabetes, hypertension, congestive heart failure). Depressive symptoms were measured using the PROMIS SF8a scale. Multiple regression analyses tested the relationship between comorbidities and depressive symptoms, adjusting for sociodemographic factors.
Results: Overall, 25% of participants had moderate-severe levels of depressive symptoms, 87% had ≥ two comorbidities, and 41% had ≥ one comorbidity with self-management intensive needs. The count of all comorbidities was significantly associated with depressive symptoms (F (8, 330) = 7.7, p < 0.0001, R2 = 0.158) in adjusted models, whereas the count of self-management intensive conditions was not significantly associated with depressive symptoms in adjusted analyses.
Conclusions: In older adults with asthma and multiple comorbidities, depressive symptoms increased with the overall count of comorbidities but not with the count of comorbidities with self-management intensive needs. Given the impact of depression on asthma outcomes for older adults, the mechanisms by which comorbid illness contributes to depressive symptoms in older asthmatics warrants further evaluation.
Keywords: Comorbidity; depression; multimorbidity; older adults; self-management.