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

ABSTRACT

Objectives

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.

Methods

We followed PRISMA guidelines to perform a systematic identification of relevant publications in the literature on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL.

Results

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 moderate effect increase in the mean duration of hospital stay (Hedge’s g, 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.

Conclusion

The current systematic review and meta-analysis provide evidence regarding the detrimental consequences of anemia on the morbidity and mortality of patients with COPD.

KEYWORDS:

• Hemoglobin
• anemia
• morbidity
• mortality

Article highlights

• We synthesized the evidence on the effects of anemia on the morbidity and mortality of patients with COPD following PRISMA guidelines.

• Our analyses included data from 420 970 individuals with COPD with or without anemia from 15 relevant publications.

• The results of our meta-analysis provide a 2b evidence level suggesting that anemia increases the hospital stay durations, the Charlson comorbidity index scores, and the mortality rates of patients with COPD.

Author contributions

Y Xu and R Chen conceived and designed the study. T Hu and H Ding collected the data and performed the literature search. Y Xu wrote the manuscript.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplemental material

Supplemental data for this article can be accessed here.

Additional information

Funding

This paper was funded by Jiangsu Province Science & Technology Department [grant number: BE2016710].