Determining Cut Points in Gait Speed to Analyze Mobility Limitations

Recently published in the Journals of Gerontology, Series A, Biological Sciences and Medical Sciences, researchers, including UPMC’s Anne Newman, MD, MPH, completed a pooled analysis to determine what cut point in gait speed discriminates community dwelling older adults with mobility complaints from those without. 

Historically, cut points to define slow walking speed have been derived largely by expert opinion. Few, if any, analyses have utilized a data-driven approach to determine cut points that classify people as slow through self-reporting. There are implications for incorporating slowness into definitions of certain conditions such as sarcopenia and frailty, making a data-driven definition of slowness increasingly important. 

The research team used classification and regression tree analysis — with a subset of cross-sectional data from studies of older adults in the Sarcopenia Definitions and Outcomes Consortium — to determine cut points in gait speed that best differentiate those who report mobility limitations and those who do not. 

Mobility limitation was defined as self-reported difficulty with walking approximately 1/4 mile (prevalence: 12.6% men and 26.4% women).

In women, two cut points were identified, categorizing 82.2% of female participants as fast (≥0.75 m/s); 9.5% as intermediate (≥0.62 ms/s but <0.75 m/s); and 8.3% as slow (<0.62 m/s). In men, three cut points were identified, categorizing 73.6% of male participants as very fast (≥1.00 m/s); 21.3% as fast (≥0.74 m/s but <1.00 m/s); 3.7% as intermediate (≥0.57 m/s but <0.74 m/s); and 1.4% as slow (<0.57 m/s).

Overall, cut points of approximately 0.60 m/s and 0.75 m/s differentiate those with self-reported mobility limitation from those without for both men and women. Rounding the two slower cut points reclassified very few patients.

These cut points should be considered in situations where categorized values of walking speed are required – such as clinical trial eligibility or follow-up treatment determination.

Read the full study here.  

About Dr. Newman

Anne Newman, MD, MPH, is professor and chair of the Department of Epidemiology in the Graduate School of Public Health at the University of Pittsburgh with a secondary appointment in the Department of Medicine, Division of Geriatric Medicine and with the Clinical and Translational Science Institute at the University of Pittsburgh.
Her research interests include the relationships between aging and longevity, disability, sarcopenia, and atherosclerosis. 

Reference 

Cawthon PM, Patel SM, Kritchevsky SB, Newman AB, Santanasto A, Kiel DP, Travison TG, Lane N, Cummings SR, Orwoll ES, Kwok T, Hirani V, Schousboe J, Karlsson MK, Mellström D, Ohlsson C, Ljunggren Ö, Xue QL, Shardell M, Jordan JM, Pencina KM, Fielding RA, Magaziner J, Correa-de-Araujo R, Bhasin S, Manini TM. 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. J Gerontol A Biol Sci Med Sci. 2021 Jun 24:glab183. doi: 10.1093/gerona/glab183. Epub ahead of print. PMID: 34166490.