Objective:To analyze the relationship between gait speed or grip strength and all-cause mortality in elderly inpatients over 75 years old, and to compare their predictive value for all-cause mortality.Methods:A prospective cohort study was conducted and enrolled elderly patients aged ≥75 years hospitalized from December 2016 to December 2019 at the Department of Integrated Medicine and Geriatrics, Fuxing Hospital, Capital Medical University.Gait speed(m/s)and grip strength(kg)were respectively measured via the 6-meter walk test and a dynamometer.The patients were followed up for more than 1 year after discharge, and the time of all-cause mortality was recorded.The Cox regression model was used to analyze the correlation between gait speed, grip strength or their combination and the risk of all-cause mortality.ROC curves were statistically analyzed using the DeLong test.Results:A total of 704 patients were enrolled, with an average age of(83.8±6.3)years; the median follow-up time was 33(24, 42)months.During the follow-up period, all-cause death occurred in 131 cases(18.6%).Compared with the high gait speed and high grip strength groups, the low gait speed and low grip strength groups had higher all-cause mortality(all P<0.05).The Cox regression model was used to analyze the relationships between gait speed, grip strength and all-cause mortality.The results showed that gait speed( HR=2.255, 95% CI: 1.462-3.477, P<0.001)and grip strength( HR=1.815, 95% CI: 1.232-2.673, P<0.001)were associated with the risk of all-cause mortality after adjustment for other factors; When gait speed slowed down and grip strength decreased, the risk of death reached the highest level( HR=3.156, 95% CI: 1.829-5.445, P<0.001).The AUC of the gait speed model(0.703, 95% CI: 0.667-0.736)was higher than the AUC of the grip strength model(0.648, 95% CI: 0.611-0.683), with a difference of 0.055(95% CI: 0.006-0.103, P=0.026). Conclusions:Decreased gait speed or grip strength is related to an increase of death risk.The risk of death is highest when the patient has both slowed gait speed and decreased grip strength.The predictive value of gait speed for death is better than grip strength.Together they can be used as simple, rapid and effective tools to predict all-cause mortality in this population.