Prognosis of Patients with Chronic Obstructive Pulmonary Disease Not Eligible for Major Clinical Trials.

Rationale: Randomized controlled trials only include a subset of patients with chronic obstructive pulmonary disease (COPD) fulfilling strict inclusion criteria. Thus, most patients with COPD in a real-world setting do not have the necessary evidence to support treatment effectiveness.

Objectives

To test the hypotheses that most individuals with COPD in the general population are not represented in major clinical trials despite clinically significant disease with exacerbations and early death.

Methods

In 105,630 adults from a Danish contemporary population-based cohort, we defined COPD as age 40 or more years, chronic respiratory symptoms, history of smoking exposure, and airflow limitation with FEV1/FVC < 0.70. Outcomes included acute exacerbations and all-cause mortality. Symptomatic smokers without COPD were used as a reference group. Measurements and Main

Results

Of all, 7,516 (7%) and 16,079 (15%) were symptomatic smokers with and without COPD. Only 44% of those with COPD were eligible for major clinical trials when applying FEV1 < 80% predicted, smoking history of 10 or more pack-years, and no comorbid asthma as common inclusion criteria. During the median 8.9 years of follow-up, we observed 2,130 acute exacerbations and 3,973 deaths in symptomatic smokers. Compared with symptomatic smokers without COPD, multivariable-adjusted hazard ratios for exacerbations were 7.45 (95% confidence interval, 5.41-10.3) and 29.0 (21.1-39.8) in those with COPD, respectively, excluded and eligible for clinical trials. Corresponding hazard ratios for all-cause mortality were 1.21 (1.11-1.31) and 1.67 (1.54-1.81), respectively.

Conclusions

More than half of individuals with COPD in the general population are excluded from major clinical trials; however, these individuals have a clinically significant disease with exacerbations and early death compared with symptomatic smokers without COPD.