Effects of anemia on the survival of patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

Anemia is often seen in chronic obstructive pulmonary disease (COPD) patients. However, the implications of anemia on the outcomes of patients with COPD is not clearly known. Therefore, we conducted a systematic review and meta-analysis to evaluate the effects of anemia on the morbidity and mortality of patients with COPD. We followed PRISMA guidelines to perform a systematic identification of relevant publications in the literature on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. Out of 1845 records, we included data from 15 articles including 420 970 participants in this review. Our systematic review presents a 2b level of evidence suggesting a higher duration of hospital stay, Charlson comorbidity index score, and mortality rate for patients with COPD and anemia than for patients with COPD without anemia. The meta-analysis revealed a <i>moderate</i> effect increase in the mean duration of hospital stay (Hedge’s <i>g</i>, 0.55), Charlson comorbidity index (0.68), and mortality rate (0.49) in patients with COPD and anemia as compared to those in patients with COPD without anemia. The current systematic review and meta-analysis provide evidence regarding the detrimental consequences of anemia on the morbidity and mortality of patients with COPD.