Background: Chronic obstructive pulmonary disease (COPD) is usually assessed using FEV(1) to establish the diagnosis and the severity of the disease. However, COPD is now considered a systemic disease.
Aim: To evaluate the utility of the Health-Activity-Dyspnoea-Obstruction (HADO) score for classifying the severity of COPD and predicting outcomes.
Design: Prospective longitudinal clinical study.
Methods: We studied 611 consecutive patients with stable COPD in five out-patient clinics of a teaching hospital. We measured dyspnoea degree, pulmonary function (by spirometry), self-reported level of daily physical activity and overall health condition. Outcome measures included health-related quality of life (HRQoL) parameters (as measured by the generic SF-36 Health Survey and by two specific questionnaires, the St George Respiratory Questionnaire and the Chronic Respiratory Questionnaire) and mortality at 3 years follow-up.
Results: Based on the HADO score, COPD was classified as mild in 26.7% of patients, moderate in 53.3%, and severe in 20%. There were statistically significant correlations between these three levels of severity and HRQoL parameters and vital status. After adjustment for relevant covariates, the HADO score reliably predicted survival and vital status.
Discussion: The HADO score can be easily obtained in an out-patient clinic, and distinguishes groups of COPD patients by their disease severity. The HADO score is better than FEV(1%) alone for predicting mortality at 3 years.