What cut-point in gait speed best discriminates community-dwelling older adults with mobility complaints from those without? A pooled analysis from the sarcopenia definitions and outcomes consortium

Authors: CAWTHON, PEGGY - California Pacific Medical Center Research Institute; PATEL, SHEENA - California Pacific Medical Center Research Institute; KRITCHEVSKY, STEPHEN - Wake Forest School Of Medicine; NEWMAN, ANNE - University Of Pittsburgh; SANTANASTO, ADAM - University Of Pittsburgh; KIEL, DOUGLAS - Beth Israel Deaconess Medical Center; TRAVISON, THOMAS - Beth Israel Deaconess Medical Center; LANE, NANCY - University Of California; CUMMINGS, STEVEN - California Pacific Medical Center Research Institute; ORWOLL, ERIC - Oregon Health & Science University; DUCHOWNY, KATE - University Of California San Francisco (UCSF); KWOK, TIMOTHY - The Chinese University Of Hong Kong (CUHK); HIRANI, VASANT - University Of Sydney; SCHOUSBOE, JOHN - University Of Minnesota; KARLSSON, MAGNUS - Lund University; MELLSTROM, DAN - University Of Gothenburg; OHLSSON, CLAES - University Of Gothenburg; LJUNGGREN, OSTEN - Uppsala University; XUE, QIAN-LI - Johns Hopkins University; SHARDELL, MICHELLE - University Of Maryland; JORDAN, JOANNE - University Of North Carolina; PENCINA, KAROL - Harvard Medical School; FIELDING, ROGER - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; MAGAZINER, JAY - University Of Maryland; CORREA-DE-ARAUJO, ROSALY - National Institute On Aging (NIA, NIH); BASHIN, SHALENDAR - Harvard Medical School; MANINI, TODD - University Of Florida

Submitted to: Journals of Gerontology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2021
Publication Date: 6/24/2021
Citation: Cawthon, P.M., Patel, S.M., Kritchevsky, S.B., Newman, A.B., Santanasto, A., Kiel, D.P., Travison, T.G., Lane, N., Cummings, S.R., Orwoll, E.S., Duchowny, K.A., Kwok, T., Hirani, V., Schousboe, J., Karlsson, M.K., Mellstrom, D., Ohlsson, C., Ljunggren, O., Xue, Q., Shardell, M., Jordan, J.M., Pencina, K.M., Fielding, R., Magaziner, J., Correa-De-Araujo, R., Bashin, S., Manini, T.M. 2021. What cut-point in gait speed best discriminates community-dwelling older adults with mobility complaints from those without? A pooled analysis from the sarcopenia definitions and outcomes consortium. Journals of Gerontology. https://doi.org/10.1093/gerona/glab183.
DOI: https://doi.org/10.1093/gerona/glab183

Interpretive Summary: The appropriate definition of "slow" walking speed has usually been determined by expert opinion. We examined walking speed in over 18,000 men and women greater than 65 years old. Using state of the art statistical techniques, we identified a walking speed of 0.6 meters per second as being "slow" and associated with an increased occurrence of difficulties with mobility and a walking speed of 0.75 meters per second as being "fast" and associated with a low occurence of difficulties with mobility. The walking speeds of 0.6 and 0.75 meters per second can discriminate older adults with self-reported mobility difficulties from those without.

Technical Abstract: Background: Cut-points to define slow walking speed have largely been derived from expert opinion. Methods: Study participants (13 589 men and 5043 women aged >/= 65years) had walking speed (m/s) measured over 4-6 m (mean +/- SD: 1.20 +/- 0.27 m/s in men and 0.94 +/- 0.24 m/s in women.) Mobility limitation was defined as any self-reported difficulty with walking approximately 1/4 mile (prevalence: 12.6% men, 26.4% women). Sex-stratified classification and regression tree (CART) models with 10-fold cross-validation identified walking speed cut-points that optimally discriminated those who reported mobility limitation from those who did not. Results: Among 5043 women, CART analysis identified 2 cut-points, classifying 4144 (82.2%) with walking speed >/= 0.75 m/s, which we labeled as "fast"; 478 (9.5%) as "intermediate" (walking speed >/= 0.62 m/s but <0.75 m/s); and 421 (8.3%) as "slow" (walking speed <0.62 m/s). Among 13 589 men, CART analysis identified 3 cut-points, classifying 10 001 (73.6%) with walking speed >/=1.00 m/s ("very fast"); 2901(21.3%) as "fast" (walking speed >/=0.74 m/s but <1.00 m/s); 497 (3.7%) as "intermediate" (walking speed >/=0.57 m/s but <0.74 m/s); and 190(1.4%) as "slow" (walking speed <0.57 m/s). Prevalence of self-reported mobility limitation was lowest in the "fast" or "very fast" (11% for men and 19% for women) and highest in the "slow" (60.5% in men and 71.0% in women). Rounding the 2 slower cut-points to 0.60 m/s and 0.75 m/s reclassified very few participants. Conclusions: Cut-points in walking speed of approximately 0.60 m/s and 0.75 m/s discriminate those with self-reported mobility limitation from those without.