In between exacerbations, chronic obstructive pulmonary disease (COPD) is usually regarded as a stable condition, but there is increasing recognition of variability in this state. This cross-sectional study assessed patients' perception of symptom variability. Participants were outpatients > 45 yrs old with COPD, current or ex-smokers, forced expiratory volume in 1 s (FEV₁) <50% predicted, FEV₁/forced vital capacity < 0.7 and no exacerbation leading to therapeutic intervention in the previous 3 months. Patients' perceptions of COPD symptoms and their impact on daily life activities were recorded. Alterations in therapy use in response to COPD worsening were also recorded. COPD symptoms were experienced by 2,258 (92.5%) out of 2,441 patients during the 7 days before interview. Breathlessness was the most common symptom (72.5%). Daily and/or weekly symptom variability was reported by 62.7% of symptomatic patients; the morning was the worst time of day. Factors associated with perception of variability of breathlessness included younger age, symptom severity and recruitment to the study by general practitioners. The perception of variability was significantly different between European countries or regions. Patient-perceived COPD symptoms vary over the day and the week, and impact on daily activities; morning being the worst time of day. The majority of patients appear not to adjust treatment when symptoms worsen.
Trial registration: ClinicalTrials.gov NCT00722267.