OBJECTIVE: To assess the effects of depressive symptoms on asthma patients’ reports of functional status and health-related quality
of life.
DESIGN: Cross-sectional study.
SETTING: Primary care internal medicine practice at a tertiary care center in New York City.
PATIENTS: We studied 230 outpatients between the ages of 18 and 62 years with moderate asthma.
MEASUREMENTS AND MAIN RESULTS: Patients were interviewed in person in English or Spanish with two health-related quality-of-life measures, the disease-specific
Asthma Quality of Life Questionnaire (AQLQ) (possible score range, 1 to 7; higher scores reflect better function) and the
generic Medical Outcomes Study SF-36 (general population mean is 50 for both the Physical Component Summary [PCS] score and
Mental Component Summary [MCS] score). Patients also completed a screen for depressive symptoms, the Geriatric Depression
Scale (GDS), and a global question regarding current disease activity. Stepwise multivariate analyses were conducted with
the AQLQ and SF-36 scores as the dependent variables and depressive symptoms, comorbidity, asthma, and demographic characteristics
as independent variables. The mean age of patients was 41 ± SD 11 years and 83% were women. The mean GDS score was 11 ± SD
8 (possible range, 0 to 30; higher scores reflect more depressive symptoms), and a large percentage of patients, 45%, scored
above the threshold considered positive for depression screening. Compared with patients with a negative screen for depressive
symptoms, patients with a positive screen had worse composite AQLQ scores (3.9±SD 1.3 vs 2.8±SD 0.8, P<.0001) and worse PCS scores (40±SD 11 vs 34±SD 8, P<.0001) and worse MCS scores (48±SD 11 vs 32±SD 10, P<.0001) scores. In stepwise analyses, current asthma activity and GDS scores had the greatest effects on patient-reported
health-related quality of life, accounting for 36% and 11% of the variance, respectively, for the composite AQLQ, and 11%
and 38% of the variance, respectively, for the MCS in multivariate analyses.
CONCLUSIONS: Nearly half of asthma patients in this study had a positive screen for depressive symptoms. Asthma patients with more depressive
symptoms reported worse health-related quality of life than asthma patients with similar disease activity but fewer depressive
symptoms. Given the new emphasis on functional status and health-related quality of life measured by disease-specific and
general health scales, we conclude that psychological status indicators should also be considered when patient-derived measures
are used to assess outcomes in asthma.
Key words asthma - depressive symptoms - quality of life - global measure
This project was supported by a Robert Wood Johnson Foundation Generalist Physician Faculty Scholar’s Award to Dr. Mancuso.