A 10-item frailty index based on a comprehensive geriatric assessment (FI-CGA-10) in older adults with cancer: Development and construct validation.

Abstract

e24011 Background: A frailty index based on domain-level deficits in a comprehensive geriatric assessment (FI-CGA) has been previously developed and validated in general geriatric patients (Jones D, Aging Clin Exp Res 2005). Our objectives were to construct an FI-CGA and to assess its construct validity in geriatric oncology setting. Methods: Consecutive older adults with cancer who underwent a CGA on a geriatric oncology service were included. We developed a 10-item frailty index based on deficits in 10 domains (FI-CGA-10): cognition, mood, communication, mobility, balance, nutrition, basic and instrumental activities of daily living, social support and comorbidity. Deficits in each domain were scored as 0 (no problem), 0.5 (minor problem) and 1.0 (major problem). Scores were calculated by dividing the sum of the score of each domain by 10, and categorized as fit ( < 0.2), pre-frail (0.2–0.35), and frail ( > 0.35). Construct validity was tested by comparing the FI-CGA-10 with the following established frailty measures: the Canadian Study of Health and Aging (CSHA) Clinical Frailty Scale (CFS), CSHA rules-based frailty definition and CSHA Function Scale. To evaluate the ability to predict mortality, we tested association between the FI-CGA-10 and validated prognostic indices for mortality: the Lee index and Schonberg index (higher scores reflect a higher risk of mortality). We also examined associations between the FI-CGA-10 and several features commonly seen in frail older adults such as function (Timed Up & Go (TUG) test), cognitive impairment (Mini-Cog), and high comorbidity burden (Charlson Comorbidity Index (CCI)). Results: Of 540 patients (median age 80 years, range 66–96 years), common cancer types were gastrointestinal tract in 37%, hepatobiliary and pancreatic in 22%, and head and neck in 12%. 406 (75%) patients had ECOG PS 0 to 1. The FI-CGA-10 had a right-skewed distribution and was well approximated by the gamma distribution. Overall, 20% of patients were fit, 41% were pre-frail, and 39% were frail. The FI-CGA-10 was highly correlated with CSHA CFS (Pearson's r = 0.83), CSHA rules-based frailty definition (r = 0.67) and CSHA Function Score (r = 0.77). People who were more frail had higher scores on the Lee index (fit: 7.3, prefrail: 8.8, frail: 12.0; p < .0001) and Schonberg index (fit: 10.1, prefrail: 13.1, frail: 15.7; p < .0001), suggesting an increased probability of death. Increasing levels of frailty were significantly associated with a longer TUG (seconds), fit: 11.3, prefrail: 13.0, frail: 26.3; p < .0001, poorer cognitive function (Mini-Cog score, fit: 4.7, prefrail: 4.0, frail: 3.1; p < .0001), and higher comorbidity burden (CCI, fit: 0.8, prefrail: 1.4, frail: 1.9; p < .0001). Conclusions: The FI-CGA-10 is a clinically sensible and construct-validated measure of quantifying frailty from a CGA.