AS compared with placebo,antibiotics decrease the relative risk of treatment failure by approximately 50％when used for COPD exacerbations.Subgroup analysis suggests that antibiotics are most effective when cough and sputum purulence are present.Most trials suggesting the efficacy of antibiotics have compared the use of older antibiotics with placebo.It iS uncertain whether newer classes of antibiotics,such as macrolides and fluoroquinolones.are more effective.Initial outpatient treatment with antibiotics should be based on considerations of cost.safety,and locaI patterns of antibiotic resistance among the bacterial species commonly isolated from sputum during exacerbations.

If an exacerbation is associated with increased breathlessness,patients should be encouraged to increase their use of short-acting bronchodilators.Anticholinergic and β2-agonist bronchodilatorsappear to be equally effective,with little additive benefit from combined use.Areas of Uncertainty

It remains unclear whether spirometry is routinely warranted to diagnose COPD in persons atrisk who are asymptomatic.Whereas the National Lung Health Education Program has advocatedwidespread spirometric testing in medical offices(including testing in persons at risk who do nothave respiratory symptoms)to identify cases of COPD,an evidence-based report sponsored by theAgency for Healthcare Research and Quality concluded that screening persons who are at risk but are asymptomatic would raise overall costs,falsely label many of those tested as having clinically significant disease,and only marginally improve clinical outcomes.In randomized trials,smoking-cessation rates were not increased among patients with early COPD who underwent spirometrictesting and were informed of abnormal results,as compared with patients who did not undergo testing.However,in a recent trial comparing two approaches to informing patients of spirometric results-assigning a"lung age"versus simply reporting the FEV1--the former approch was associated with higher cessation rates at 1 year,which suggests that spirometry may facilitate smoking cessation if the results are presented to patients in an appropriate manner.

The role of disease-management programs for patients with COPD remains uncertain.Randomized.controlled trials of case management for COPD have shown promise in reducing hospitalization rates,but the evidence is insufficient to make specific recommendations.Pulmonary rehabilitation improves health status and exercise capability for selected patients,but national surveys indicate that few patients complete such programs.and it iS unclear how best to maintain the benefits achieved.