Hospital Frailty Risk Score May Misclassify Patients With COPD

In older adults with chronic obstructive pulmonary disease (COPD), use of the population-based Hospital Frailty Risk Score (HFRS) to screen for frailty was associated with poor detection of frailty among hospitalized patients with COPD, compared with use of the bedside Clinical Frailty Scale (CFS), according to findings from a study published in JAMA Network Open.

Although frailty among hospitalized older adults with COPD is associated with severe morbidity and mortality, frailty is not routinely measured in pulmonary practice — even though an intervention such as pulmonary rehabilitation might potentially treat and reverse this multidimensional syndrome of frailty. Researchers therefore sought to explore and compare frailty screening tools used in the hospital setting for patients with COPD, specifically comparing the HFRS, a population-based administrative data tool, and the CFS, a standard bedside evaluation.

The cross-sectional, observational study was conducted in the respiratory ward of a single tertiary care academic hospital — the Ottawa Hospital, in Ottawa, Ontario, Canada. Study participants comprised adult inpatients admitted with a diagnosis of acute COPD exacerbation between December 2016 and June 2019. The data analysis was carried out in March 2022.

The primary study outcomes included the sensitivity and the specificity of the HFRS to detect frail and nonfrail individuals based on CFS evaluations of frailty. The secondary study outcome was the optimal probability threshold of the HFRS to differentiate between frail and nonfrail participants. Hospital administrative data were used to calculate the HFRS.

Among a total of 99 patients with exacerbations of COPD, application of the CFS found that 14% were not frail, 33% were vulnerable, 18% were mildly frail, and 34% of them were moderately to severely frail. The mean (SD) participant age was 70.6 (9.5) years. Overall, 56 of the patients were women.

Results of the study showed that compared with the CFS, the HFRS had a sensitivity of 27% and a specificity of 93% for the detection of frail vs nonfrail individuals with COPD exacerbations. The optimal probability threshold for the HFRS was 1.4 points or more. The corresponding sensitivity to detect frailty was 69%, whereas the specificity was 57%.

Limitations of this study include selection bias; use of the HFRS on a population that is younger than the population for which the tool was intended (it was validated in a population of patients older than 75 years of age); and the study’s small sample size and use of a single tertiary center, which both limit the applicability of the findings.

“These findings suggest that use of the Hospital Frailty Risk Score, which relies on administrative health data to identify frailty among patients with COPD, may misclassify frail patients as nonfrail, thus missing important opportunities for early identification and intervention to improve frailty,” the study authors concluded.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

This article originally appeared on Pulmonology Advisor