Aim: There is emerging evidence for using the Frailty Index as an objective measure of frailty. This is likely to have utility in the management of older cancer patients. We constructed a Frailty Index from patient derived outcome measures (PROM), as well as self-reported comorbidity data and tested its correlation with survival.
Method: Data from 464 patients with lung, breast and colorectal cancer were obtained from the Continuous Improvement in Care - Cancer Project database and a 42-variable Frailty Index was generated. It was calculated by dividing the total number of deficits present by the total number assessed and expressed as a ratio between 0 and 1. Frailty was defined as a Frailty Index of >0.2. Its association with survival was assessed using Cox Proportional Hazard Models.
Results: Frailty index scores ranged from 0.00 to 0.58 (mean = 0.16, standard deviation = 0.12) and approximated a gamma distribution. Each year of patient age was associated with a small but significant increase in scores (0.001 points, P = .035). Among patients with lung cancer or colorectal cancer, women had significantly higher scores than men (mean difference = 0.06, P = .003). For every 0.1 increase in Frailty Index, there was a statistically significant increased risk of death. The probability of mortality was higher in the frail cohort compared to the non-frail cohort (HR 1.96, P = .027).
Conclusion: Our data suggests that a self-reported PROM and comorbidity-derived Frailty Index is feasible and a valid measure of frailty in oncology patients.