Eosinophil Counts Determine COPD-Related Healthcare Resource Utlization

Evaluating the relationship between chronic obstructive pulmonary disease (COPD) characteristics and burden on the healthcare system, researchers found that patients with blood eosinophil (EOS) counts of 150 cells/mcL or greater had increased COPD-related healthcare resource utilization compared with patients with EOS counts less than 150 cells/mcL.

The study of more than 34,000 patients, which included patients receiving multiple inhaler triple therapy (MITT) and patients not receving MITT, demonstrated that EOS counts of 150 cells/mcL or greater were associated with increased healthcare resource utilization use regardless of MITT use. Patient data from between January 1, 2011, and December 31, 2016, were obtained from the US IBM Watson Explorys real-world database.

Among patients not receiving MITT, the number of emergency department (ED) visits (3.0 vs 2.5), outpatient visits (6.3 vs 6.1), and pharmacy prescriptions (11.1 vs 10.5) per patient per year were significantly higher among patients with EOS counts of 150 cells/mcL or greater compared with patients with EOS counts less than 150 cells/mcL. Similar patterns were seen among patients receiving MITT: Patients with EOS counts of 150 cells/mcL or greater had significantly higher rates of ED visits (3.4 vs 3.1) and pharmacy prescriptions (16.4 vs 16.1).

Utilization was highest among patients with EOS counts of 150 cells/mcL or greater who were receiving MITT, and these patients also had a higher proportion of COPD-related pharmacy encounters for all drug classes compared with patients not receiving MITT.

High levels of inflammatory eosinophil cells in the blood have previously been indicated as a potential indicator of poor symptom control despite adherence to recommended therapies.

“It is known that patients with COPD, particularly those with frequent exacerbations, may display signs of systemic inflammation, such as elevated blood EOS counts, circulating inflammatory cytokines, and acute-phase proteins,” wrote the researchers. “Systemic inflammation may, in turn, contribute to higher levels of comorbid disease and poor clinical outcomes.”

Looking at exacerbations, the authors observed moderate exacerbations were significantly more frequent in subgroups with EOS counts of 150 cells/mcL or greater, regardless of MITT use. However, there were no significant differences in severe exacerbations between those with the higher EOS counts and those with lower counts, with mean rates ranging between 0.65 and 0.85 per patient per year.

Patients with EOS counts of 150 cells/mcL or greater who were receiving MITT experienced the highest mean numbers of moderate exacerbations (2.26 per patient per year) compared with the other subgroups (1.82-2.16 per patient per year).

According to the researchers, both patients and the healthcare system will likely benefit from new treatment options targeted at reducing exacerbations in patients with elevated EOS levels who continue to experience exacerbations despite maximal inhaled therapy.

Reference

Mullerorva H, Hahn B, Simard E, Mu G, Hatipoglu U. Exacerbations and health care resource use among patients with COPD in relation to blood eosinophil counts [published online March 22, 2019]. Int J Chron Obstruct Pulmon Dis. doi: 10.2147/COPD.S194367.