Risk factors for exacerbation in chronic obstructive pulmonary disease: a prospective study.

BACKGROUND

Although acute exacerbations are key events in the progression of chronic obstructive pulmonary disease (COPD), their frequency and the factors associated with acute exacerbation are not fully known.

OBJECTIVE

To determine the incidence and risk factors of very frequent exacerbations in COPD (⩾3 per year).

PATIENTS AND

METHODS

In a cohort study to analyse acute exacerbation and associated factors in 512 primary care patients during a 2-year follow-up, variables of interest were collected for each patient. Acute exacerbation was defined as an event that required antibiotics and/or systemic steroids (moderate) or hospital admission (severe). Odds ratios (OR) were used to determine factors associated with exacerbation.

RESULTS

Incidence of exacerbation was 61.7% in the first year of follow-up and 63.9% in the second year. During the first year, the factors associated with very frequent exacerbation were previous hospital admission (OR 1.69), dyspnoea (moderate [OR 2.86] and severe-very severe [OR 5.83]) and the Charlson Index (OR 1.19); during the second year, associated factors were female sex (OR 4.17), history of previous hospital admissions (OR 2.90), smoking (smoker/ex-smoker) (OR 2.00) and forced vital capacity (OR 0.98).

CONCLUSIONS

Incidence of exacerbation is high in COPD patients. Previous admission for exacerbation is a strong predictor and can identify patients at risk.