COPD Exacerbation Readmission Risk Higher in Men and Those With Comorbidities

Common risk factors for readmissions from acute exacerbations of chronic obstructive pulmonary disease (COPD) include male sex, comorbidities, number of hospitalizations in the previous year, and length of stay (LOS), according to a systematic review and meta-analysis published in Respiratory Medicine.

Readmission rates due to acute exacerbations of COPD are high, placing significant socioeconomic burdens on global health care. Reviewers sought to calculate readmission rates for acute exacerbations of COPD and to characterize the risk factors underlying these readmissions.

Reviewers searched for studies involving COPD, readmission, and risk factors in the Cochran Library, Embase, PubMed, and Web of Science databases through April 2022. The Newcastle-Ottawa Scale was used by 2 researchers to assess methodological quality. Pooled COPD readmission rates for acute exacerbations and underlying risk factors were estimated with fixed-effects or random effects models.

The meta-analysis, which included 46 studies, found that pooled readmission rates for COPD acute exacerbations were:

• within 30 days: 11% (range, 6% to 24%; 95% CI, 0.09-0.13; I²=99.94%; based on 24 studies);
• within 60 days: 17% (range, 7% to 39%; 95% CI, 0.10-0.25; I²=98.61%; based on 7 studies);
• within 90 days: 17% (range, 10% to 41%; 95% CI, 0.15–0.19; I²=98.60%; based on 17 studies);
• within 180 days: 30% (range, 18% to 50%; 95% CI, 0.25–0.35; I²=99.38%; based on 7 studies); and
• within 365 days: 37% (range, 18% to 76%; 95% CI, 0.34–0.40; I²=99.08%; based on 20 studies).

Sensitivity analysis revealed 1 study interfered by 5% with the pooled readmission rate within 180 days.

The 46 studies analyzed were published from 2001 to 2022 and were mostly conducted within various regions defined by the World Health Organization (WHO), including 21 studies conducted in the European region, 13 in the Americas region, 9 in the Western Pacific region, and 2 in the Eastern Mediterranean region, while 1 was conducted in a WHO nonmember observer country. Of the studies analyzed, 27 were retrospective (1 case-control study, 26 cohort studies) and 19 were prospective; sample sizes ranged from 79 to over 300,000. Patients’ average ages ranged from 54.0 to 76.8 years.

Potential risk factors for COPD readmission were identified as male sex, comorbidities (including diabetes, heart failure, and cancer), previous-year hospitalizations, and length of stay. Obesity was identified as a protective factor. Comorbidities of anemia, depression, and pneumonia were not statistically significant in pooled analysis.

Study limitations include the use of only studies that were published in English for the analysis; unaccounted for deaths outside of hospitals; high heterogeneity among the included studies; and lack of subgroup analyses of disease severity or pulmonary function classification.

“[T]his study is the first to systematically evaluate and summarize acute exacerbation readmission rates and risk factors for readmission in patients with COPD within 30, 60, 90, 180, and 365 days after discharge, respectively,” study authors noted. “Male

sex, number of hospitalizations in the previous year, LOS, and comorbidities were the most common risk factors for readmission,” said reviewers. They concluded that the readmission rate for acute exacerbations in patients with COPD is generally high, and that clinical interventions are needed to control avoidable risk factors for COPD readmission.