The investigators identified male and female patients, ages 40 and older, who were enrolled in the Lovelace and Kaiser Permanente-Georgia health plans during 1995 to 2000 and who had a diagnosis of COPD. In total, 1,685 patients were identified: the 'exposed groups' consisted of patients who had 90 days or more use of ICS (n= 786), ICS plus salmeterol (n=332) or salmeterol without ICS (n=170); the reference, or 'unexposed,' group (n=397) were patients who had not used ICS or a long-acting beta2-agonist but had been exposed to another respiratory drug for 90 days or more.
During the study period, 28 percent of patients in the unexposed group died compared to 14 percent of patients who had been exposed to ICS and/or salmeterol. In a statistical model that controlled for age, sex, comorbid conditions, COPD severity, and asthma status and severity, exposure to either ICS (Hazard Ratio [HR] 0.59, 95% Confidence Interval [CI]: 0.46, 0.78) or salmeterol (Hazard Ratio [HR] 0.55, 95% Confidence Interval [CI]: 0.34, 0.89) were associated with a decreased risk of death. In addition, exposure to ICS plus salmeterol also reduced the risk of death (HR 0.34, 95% CI: 0.21, 0.56). In a sensitivity analysis including only those COPD patients without a history of asthma (n=840), the reduction in risk of death associated with the use of ICS plus salmeterol remained significant (HR 0.35, 95% CI: 0.17, 0.71). Use of inhaled corticosteroids was associated with longer survival in COPD patients, independent of an asthma diagnosis, age, gender, or COPD severity.
According to the CDC, approximately 24 million Americans have evidence of impaired lung function consistent with a diagnosis of COPD, the f