Background: Some investigations have revealed an association between depression and physical measurements of COPD patients in North America and Europe, but few related studies have been performed in Asia.
Methods: In this cross-sectional study, 84 consecutive, stable out-patients with COPD (mean ± SD age 72.0 ± 9.0 y, percent-of-predicted FEV1 46 ± 15%, 15 [17.9%] female) in a Japanese community hospital were recruited. "Probable depression" was defined as a score of ≥ 6 on the short-form Geriatric Depression Scale (SF-GDS). Relationships among commonly used physical measurements, SF-GDS raw score, and probable depression were evaluated with the Spearman rank correlation test, multiple linear regression analysis, logistic regression analysis, and receiver operating characteristic curves.
Results: Thirty-two subjects (38.1%) had probable depression. Body mass index, obstruction, dyspnea, exercise capacity index, percent-of-predicted FEV1, Modified Medical Research Council dyspnea score, 6-min walk distance, and SpO2 had: simple correlations (r 0.42-0.60, P < .001 for all) with the SF-GDS raw score; partial correlations (r 0.25-0.51, P < .05 for all) with the SF-GDS raw score after adjusting for demographic and social factors; association with probable depression in the logistic regression analysis after adjusting for demographic and social factors (P < .05 for all); and areas under the receiver operating characteristic curve of 0.72-0.84 (P < .001 for any) for probable depression.
Conclusions: Physical parameters were associated with depression in our Japanese COPD out-patients.
Keywords: COPD; Japan; depression; geriatric.