Burden of concomitant asthma and COPD in a Medicaid population.

Background: Asthma and COPD can significantly affect patients and pose a substantial economic burden for both patients and managed-care plans. This study compares utilization outcomes in patients with asthma, COPD, or co-occurring asthma and COPD in a Medicaid population, and assesses the incremental burden of COPD in patients with asthma.

Methods: We queried medical claims of Medicaid patients aged 40 to 64 years with asthma and/or COPD filed between January 1, 2001, and December 31, 2003, from encounter data. COPD patients were identified based on at least one claim with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes 491, 492, 496; and asthma patients were identified on the basis of ICD-9 code 493 as diagnosis. We analyzed annual utilization and cost of hospitalizations, physician, and outpatient services attributable to asthma and/or COPD.

Results: The analysis included a total of 3,072 asthma, 3,455 COPD, and 2,604 COPD/asthma patients. COPD/asthma co-occurring disease has higher utilization of any service type than either disease alone. Compared with asthma patients, COPD patients were 16% and 51% more likely to use physician (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.01 to 1.34) and inpatient services (OR, 1.51; 95% CI, 1.31 to 1.74), respectively; and 60% less likely to use outpatient services (OR, 0.40; 95% CI, 0.35 to 0.46). Compared with asthma patients, COPD patients and COPD/asthma co-occurring patients cost 50% (OR, 1.50; 95% CI, 1.3 to 1.74) and five times (OR, 5.25; 95% CI, 4.59 to 6.02) more for total medical services, respectively.

Conclusion: Our data suggest that patients with COPD and co-occurring COPD/asthma were sicker and used more medical services than asthma patients. The incremental burden of COPD to patients with asthma is significant.