Purpose: How changes in depression and anxiety and well-being may fluctuate with changes in disease-specific quality of life (QOL), and further how changes in well-being may fluctuate with changes in depression and anxiety among patients with moderate and severe chronic obstructive pulmonary disease (COPD).
Methods: In a longitudinal study (as part of a randomized controlled trial), we investigated 150 patients with moderate and severe COPD at baseline, 143 at 4 weeks, and 130 at 4 months. Lung function was tested, and a questionnaire was completed at all appointments. The questions captured demographic variables, disease-specific QOL (St. George's Respiratory Questionnaire), anxiety and depression (Hospital Anxiety and Depression Scale), and well-being (World Health Organization-5 Well-being Index). Multiple regression analyses were performed.
Results: At 4 weeks and 4 months, changes in disease-specific QOL (st. β = -0.35, p < 0.001, partial (p) R (2) = 11-12 %), depression (st. β = -0.32 to -0.36, p < 0.001, pR (2) = 9-12 %), and anxiety (st. β = -0.21 to -0.40, p < 0.02-0.001, pR (2) = 4-15 %) were significantly associated with changes in well-being. Changes in disease-specific QOL were significantly associated with changes in anxiety at 4 months (st. β = 0.21, p = 0.02, pR (2) = 4 %), but not with changes in depression.
Conclusions: Changes in disease-specific QOL, depression, and anxiety were associated with changes in well-being. Changes in disease-specific QOL contributed slightly to changes in anxiety, but not to changes in depression. Well-being may capture some aspects of mental QOL in COPD patients better than depression and anxiety.
Keywords: Chronic obstructive pulmonary disease; Outcomes; Quality of life; Symptoms; Well-being.