Predictive Value of Gait Speed and Grip Strength for All-cause Mortality and Falls in Geriatric Inpatients

Abstract

Background Gait speed and grip strength are simple markers of physical capability, which are associated with adverse outcomes in the elderly. However, there are few studies on the prediction of adverse outcomes in this population by the combination of the two markers. Objective To investigate the associations of gait speed and grip strength with adverse outcomes in geriatric inpatients. Methods A cohort design was used in this study. From August 2015 to December 2018, eligible geriatric inpatients aged≥65 years were recruited from Department of Geriatrics, Fuxing Hospital, Capital Medical University. We measured the gait speed and grip strength with 6-meter walking test and dynamometer, respectively. By the gait speed, the patients were divided into tertiles (T1 group: ≤ 0.6 m/s, T2 group: >0.6-0.8 m/s, T3 group: >0.8 m/s). By the grip strength, they were divided into L1, L2 and L3 tertiles (L1 group: ≤ 21.6 kg for males, ≤ 14.6 kg for females; L2 group: > 21.6 kg but ≤ 28.2 kg for males, >14.6 kg but ≤ 19.4 kg for females; L3 group: >28.2 kg for males, >19.4 kg for females). Follow-up was conducted by telephone once every three months within one year after discharge and once half a year after this until December 31, 2019. All-cause mortality and falls were recorded. Survival curves were constructed by the Kaplan-Meier method. Cox regression analysis was used to investigate the association of gait speed, grip strength, or their combination with all-cause mortality and falls. ROC curves for comparing the ability of the two makers or their combination on predicting all-cause mortality and falls. Results Among the 685 patients, 29 (4.2%) were lost to follow-up, and the other 656 cases who finished the follow-up with complete data were included for analysis. During the follow-up period, 130 patients (19.8%) died from all causes and 147 patients (22.4%) experienced falls. There were 222, 225 and 209 patients in the low, moderate and high tertiles of gait speed (T1, T2 and T3 groups), and 215, 229 and 212 patients in the low, moderate and high tertiles of grip strength (L1, L2 and L3 groups), respectively. Log-rank test showed that the cumulative survival curves of all-cause mortality and falls differed significantly among T1, T2 and T3 groups (P<0.01). The same results were obtained in L1, L2 and L3 groups (P≤0.01). Cox regression analysis with adjustment for potential confounders showed that compared to patients in high tertiles of both gait speed and grip strength, the risk of all-cause mortality significantly increased in those both in low gait speed and low or moderate tertiles grip strength〔HR=3.29, 95%CI (1.13, 9.55) ; HR=3.09, 95%CI (1.08, 8.85) ; P<0.05〕, and the risk of fall significantly increased in those in low tertiles of both gait speed and grip strength 〔HR=1.92, 95%CI (1.13, 4.27), P<0.05〕. The prediction probability of the joint diagnostic model of gait speed and grip strength was estimated by Logistic regression analysis, and the AUC of the combination of them for predicting all-cause mortality and falls was 0.756 〔95%CI (0.710, 0.801) 〕, and 0.700〔95%CI (0.659, 0.741) 〕, respectively. Conclusion In geriatric inpatients, the combination of gait speed and grip strength had higher predictive value for all-cause mortality and falls, which is helpful to optimize the health management.

Keywords

• aged|inpatients|gait speed|grip strength|death|accidental falls|forecasting|cohort studies