Objectives: To compare the effects of asthma and COPD on health status (HS) in elderly patients, and to assess the correlation between disease-specific and generic instruments assessing HS.
Design: Multicenter, cross-sectional, observational study.
Setting: The Salute Respiratoria nell'Anziano (respiratory health in the elderly) Study network of outpatient departments.
Patients: One hundred ninety-eight asthma patients and 230 COPD patients > or = 65 years old.
Measurements: HS was assessed by the Saint George's Respiratory Questionnaire (SGRQ) and five generic outcomes: Barthel's index, 6-min walk test, mini mental state examination, geriatric depression scale (GDS), and quality-of-sleep index. Independent correlates of SGRQ scores were assessed by logistic regression. Patients were considered to have a "good" HS or "poor" HS according to whether they did or did not perform worse than 75% of the corresponding population of asthma or COPD patients, on at least two of the five generic outcomes.
Results: On average, COPD patients had poorer HS than asthma patients on the SGRQ. Only polypharmacy (more than three respiratory drugs) and diagnosis of COPD qualified as independent correlates of the SGRQ score. The SGRQ "Activity" and "Impacts" scores shared the following independent correlates: polypharmacy, Barthel's index < 92, and GDS > 6. Further correlates were waist/hip ratio > 1 for the Activity score, and age and occiput-wall distance > 9 cm for the Impacts score. All sections of the SGRQ except for the Symptoms score could significantly distinguish patients with good HS and poor HS.
Conclusions: Individual dimensions of HS recognize different determinants. COPD outweighs asthma as a cause of distressing respiratory symptoms. A high degree of concordance exists between SGRQ and generic health outcomes, except for the Symptoms dimension in COPD patients.