Worsening disability linked to depression risk in COPD
MedWire News: Increases in disability levels are significantly associated with the development of depression in patients with chronic obstructive pulmonary disease (COPD), research shows.
Writing in the journal Chest, Patricia Katz (University of California, San Francisco, USA) and team explain: “Both disability and depression are common in COPD, but limited information is available on the time-ordered relationship between increases in disability and depression onset.”
To investigate, the team studied data on 341 patients, aged 55–75 years at baseline, with COPD, emphysema, or chronic bronchitis who were interviewed in 2006 (T1), 2007 (T2), and 2008 (T3).
At all three interviews, the participants completed the Geriatric Depression Scale Short Form (S-GDS) and the Valued Life Activities (VLA) scale. Using the VLA scale, the team calculated three disability scores; the percentage of VLAs a patient was unable to perform (VLA percent unable), the percentage of VLAs a patient was unable to perform or to perform with some degree of difficulty (VLA percent affected), and a patients’ mean VLA difficulty rating.
Overall, around 30% of patients at each interview met the criteria for depression, defined as a score of at least 4 on the S-GDS.
Analysis revealed that a standard deviation increase of at least 0.5 on VLA percent unable, VLA percent affected, and mean VLA difficulty scores between T1 and T2 was associated with a significantly increased risk for depression at T3, at odds ratios (ORs) of 6.1, 3.6, and 3.6, respectively.
The risk for depression at T3 associated with T1–T2 increases in VLA percent unable and mean VLA difficulty scores increased further after excluding patients who were already depressed at the first two interviews, at ORs of 13.4 and 3.9, respectively.
Katz and team conclude: “Our results provide robust evidence that increases in VLA disability precede and play an important role in the onset of depressive symptoms in individuals with COPD.
“Future research should identify factors associated with the development and progression of VLA disability, as well as factors that may protect against or ameliorate such disability. The latter is especially important, because these may represent potential targets for intervention.”
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By Mark Cowen