For the last two decades, researchers have questioned the use of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD). For a study, investigators examined the following issues in the systematic literature review and meta-analysis: Should patients with COPD with blood eosinophil counts (EOS) of less than 150 cells/μl, 150-300 cells/μl, or more than 300 cells/μl continue ICS treatment? 

On July 22, 2020, they searched Medline, Embase, CINAHL, and Cochrane Central for randomized controlled trials (RCT) of ICS therapy in patients with COPD (≥40 years, no current asthma), analyzing outcomes by EOS count and were more than 50% of patients had previously taken ICS. The GRADE technique was employed. Meta-analyses for the outcomes were separated into EOS subgroups, and differences were examined. 

They found 11 randomized controlled trials with a total of 29,654 patients. There was a significant difference (P<0.00001) in the lowering of risk of moderate to severe exacerbation between the three categories. Rate ratios for EOS counts less than 150 cells/μL was 0.88 (95% CI: 0.83, 0.94); 150–300 cells/μL was 0.80 (95% CI: 0.69, 0.94); and for more than 300 cells/μL was 0.57 (95% CI: 0.49, 0.66). Because of the possibility of bias, unexplained heterogeneity, a lack of RCTs, and large CIs, the overall certainty of the impact estimates were low to very low.

The effect of continuing ICS medication (number of exacerbations, lung function, and quality of life) on growing EOS count was demonstrated. In addition, the meta-analyses revealed that ICS therapy appeared to be effective for everyone except individuals with EOS counts less than 150 cells/μl.