Frail hospitalized patients with chronic obstructive pulmonary disease (COPD) exacerbation may be mistakenly categorized as non-frail if the Hospital Frailty Risk Score (HFRS) was used to measure frailty compared with use of the beside Clinical Frailty Scale (CFS), suggests a study published in JAMA Network Open.¹

To examine if the Clinical Frailty Scale (CFS) and the Hospital Frailty Risk Score (HFRS) were in concurrence, a research team from Canada conducted a cross-sectional study of 99 patients, mean age 70.6 years, hospitalized due to COPD exacerbation at a tertiary hospital in Ottawa from December 2016 to June 2019. Nearly 60% of the participants were women and 40.4% had heart disease. The authors also aimed to determine the sensitivity and specificity of the HFRS in detecting frailty vis-à-vis CFS assessment, which were the primary outcomes of study.

Eighty-five percent COPD patients had coexisting frailty when CFS was used. Of these, 34 (34%) had moderate to severe frailty, 18 (18%) had mild frailty, 33 (33%) patients were found to be vulnerable, while 14 (14%) were not frail.

HFRS, compared with the use of CFS as the standard diagnostic measure, which is a bedside assessment of frailty, had 27% sensitivity and 93% specificity in making a distinction between frail and non-frail patients. The optimal probability threshold for HFRS, which was the secondary outcome of the study, was determined to be 1.4 points or greater. The sensitivity for HFRS values ≥1.4 in detecting frailty as classified by the CFS was 69% and the specificity was 57%.

Out of the 33 patients identified as vulnerable with CFS, just 5 were found to be in the intermediate-risk frailty group using the HFRS. Only 4 patients were considered in the intermediate-risk frailty group by HFRS out of the 18 patients detected as mildly frail with CFS. Fifty-nine percent of the 34 patients categorized as moderately or severely frail by the CFS were categorized as a low-risk frailty group with HFRS.

The increase in the degree of frailty increased as the mean age of the subjects increased; 66.9 years among patients who were well or managing alright vs 72.2 years among those who had moderate to severe frailty. Nearly 29% of those who were either well or managing well were women, whereas women comprised 73.5% of the moderate to severe frail patients.

Frailty is very prevalent in patients with COPD, which has an adverse impact on the disease course. This study has shown the inconsistencies between CFS and HFRS in detecting frailty. The percentage of COPD patients identified as frail was much less with HFRS compared to those detected using the CFS. HFRS was also less sensitive in detecting frailty vs CFS assessment. Hence, use of HFRS, which is calculated using hospital administrative data, could miss detection of frailty in COPD patients and categorize them as non-frail leading to poor clinical outcomes with deterioration in quality of life. All COPD patients should be measured for frailty. This would enable early initiation of measures such as pulmonary rehabilitation.

Reference

1. Chin M, et al. Comparing the Hospital Frailty Risk Score and the Clinical Frailty Scale among older adults with chronic obstructive pulmonary disease exacerbation. JAMA Netw Open. 2023 Feb 1;6(2):e2253692. doi: 10.1001/jamanetworkopen.2022.53692