Combining Gait Speed and Recall Memory to Predict Survival in Late Life: Population-Based Study

Objectives: To evaluate the relationship between gait speed, recall memory, and mortality. Design: A cohort study (last follow-up December 2009). Setting: Tuscany, Italy. Participants: Individual data from 1,014 community-dwelling older adults aged 60 years or older with baseline gait speed and recall memory measurements and follow-up for a median time of 9.10 (IQR 7.1;9.3) years. Participants were a mean (SD) age of 73.9 (7.3) years, and 55.8% women. Participants walking faster than 0.8 m/s were defined as fast walkers; good recall memory was defined as a score of 2 or 3 in the 3-word delayed recall section of the Mini-Mental State Examination. Measurements: All-cause mortality. Results: There were 302 deaths and the overall 100 person-year death rate was 3.77 (95% CI: 3.37-4.22). Both low gait speed and poor recall memory were associated with mortality when analysed separately (HR = 2.47; 95% CI: 1.87-3.27 and HR = 1.47; 95% CI: 1.16-1.87, respectively). When we grouped participants according to both recall and gait speed, death rates (100 person-years) progressively increased from those with both good gait speed and memory (2.0; 95% CI: 1.6-2.5), to those with fast walk but poor memory (3.4; 95% CI: 2.8-4.2), to those with slow walk and good memory (8.8; 95% CI: 6.4-12.1), to those with both slow walk and poor memory (13.0; 95% CI: 10.6-16.1). In multivariate analysis, poor memory significantly increases mortality risk among persons with fast gait speed (HR = 1.40; 95% CI: 1.04-1.89). Conclusion: In older persons, gait speed and recall memory are independent predictors of expected survival. Information on memory function might better stratify mortality risk among persons with fast gait speed.