Multimorbidity, frailty up risk of COPD readmission

Frailty and multimorbidity may increase the likelihood of being readmitted within 30 days following an index admmission among patients with chronic obstructive pulmonary disease (COPD), reveals a Singapore study. 

However, risk adjustment revealed significant improvements in readmission risk that were not evident in unadjusted analyses, according to the researchers. 

Administrative data from October 2017 to June 2023 from Changi General Hospital, Singapore, were analysed retrospectively in this study.  

The researchers estimated unadjusted and risk-adjusted 30-day readmission odds using multivariable mixed-effects logistic regression models, which included the following covariates: age, sex, race, Charlson Comorbidity Index (CCI), Hospital Frailty Risk Score (HFRS), and year. Finally, they compared temporal trends in readmission risk across adjusted and unadjusted models. 

A total of 2,774 admissions were documented, of which 749 (27 percent) resulted in 30-day readmissions. [Ann Acad Med Singap 2025;54:419-427] 

The higher readmission risk was independently predicted by higher CCI (CCI ≥4 vs CCI 1: adjusted odds ratio [aOR], 2.00, 95 percent confidence interval [CI], 1.33–2.99; p=0.003; CCI 2–3 vs CCI 1: aOR, 1.50, 95 percent CI, 1.15–1.96; p=0.001) and higher HFRS (≥5 vs <5: aOR, 1.29, 95 percent CI, 1.01–1.65; p=0.04). 

The unadjusted analyses did not show any significant temporal trends, but the risk-adjusted model exhibited a 32-percent to 35-percent reduction in readmission odds in 2021–2023 relative to baseline. 

“These findings underscore the importance of applying risk adjustments to ensure the validity and fairness of quality metrics,” the researchers said. 

Contributing factors 

Factors both related and unrelated to quality of care could have influenced the observed reduction in the risk of readmissions. For instance, coding practices (eg, coding more comorbidities) might artificially lower the readmission risk. [JAMA Intern Med 2018;178:290-292] 

Likewise, secular trends such as global declines in COPD admissions during the COVID-19 pandemic could have affected the readmission rates. [Am J Med 2021;134:1252-1259] 

“However, our study found no significant decrease in readmission risk in 2020 despite the stringent public health measures implemented that year, nor a rebound in readmission risk in 2022 when restrictions were eased, suggesting that pandemic-related factors were not the primary drivers of observed trends,” the researchers said. 

“Temporal improvements in readmission risk may also reflect enhancements in care quality driven by targeted clinical and population health interventions implemented at our hospital,” they added. 

Improved care 

One example was the routine tracking of COPD-specific quality indicators using a dashboard. These indicators included 30-day reamission rates, mortality rates, and length of stay. Process outcomes (eg, disease education, inhaler technique, smoking cessation, pulmonary rehabilitation uptake, vaccinations) were also monitored and shared with stakeholders, with a clear chain of accountability. 

"Multidisciplinary teams support the implementation of quality improvement initiatives, including adherence to best-practice guidelines through integrated clinical pathways within electronic health records,” the researchers said.  

“Specific quality improvement projects that have been undertaken at our hospital include interventions to increase the prescribing of inpatient influenza vaccination and a multidisciplinary health management unit that meets monthly to identify high-risk patients for discussion and provide clinical, behavioural, and social management plans with the aim of preventing readmissions,” they added.