Aim: Modified-Krishnan's frailty index (FI) is an FI calculation method developed by Krishnan et al. in 2014. This study aimed to compare the effectiveness and correlation of the FIs from Krishnan and the Canadian study of health and aging (CSHA) in predicting postoperative outcomes of elderly patients with hip fracture.
Methods: Based on clinical follow-up and observation, we utilized these two instruments to predict 3-month mortality, hip function, and recovery of daily activities. The area under the curve (AUC) and the Pearson correlation coefficient were used to compare the two scales' predictive validities for postoperative outcomes.
Results: A total of 130 patients were included; 67% female and mean age 77.5 ± 8.5 years. The AUCs of modified-Krishnan's FI (AUC = 0.856; 95% confidence interval (CI) = 0.767-0.945) and the CSHA-FI (AUC = 0.793; 95% CI = 0.652-0.934) were used to compare the effectiveness in predicting patient mortality. The optimal predictive scores were 0.335 and 0.28, respectively. The Pearson correlation analysis showed that the modified-Krishnan's FI correlated with the Japanese Orthopaedic Association hip score (pain, activity, walking ability, and ability for daily living; R = -0.249, p = 0.005), while the CSHA-FI was not correlated (R = -0.125, p = 0.170). The modified-Krishnan's FI (R = -0.415, p < 0.001) and the CSHA-FI (R = -0.332, p < 0.001) were both significantly correlated with the functional recovery scale score.
Conclusions: The modified-Krishnan's FI and the CSHA-FI were effective in the prediction of postoperative mortality. But the modified-Krishnan's FI was more consistently associated with the recovery of hip function and daily activities at 3 months after the operation than that of the CSHA-FI. The modified-Krishnan's FI was more suitable to utilize for risk stratification, identifying deficits, and predicting recovery capacity in hip fracture patients.
Keywords: aged; forecasting; frailty; hip fractures; prognosis.