Interventions to reduce the frequency of exacerbations of chronic obstructive pulmonary disease.

Frequent exacerbations of chronic obstructive pulmonary disease (COPD) are associated with impaired quality of life, and hospital admissions for exacerbations account for a large proportion of the expenditure of COPD. An important objective when treating COPD is to reduce the frequency of exacerbations. Studies published in the last few years have increased our knowledge on how to prevent exacerbations, but a number of questions remain unanswered. Tiotropium, inhaled steroids and long-acting inhaled beta agonists reduce the frequency of exacerbations, but further studies are necessary to determine if combining tiotropium with the other inhaled medicines is more effective than using them separately. There is evidence that mucolytics and prophylactic antibiotics reduce exacerbations, but there is uncertainty how these treatments should be used. Both influenza and pneumococcal vaccination are recommended in guidelines, although evidence for the latter remains controversial. Other interventions including oral bacterial extracts and self-management programmes warrant further study.