Decline in walking speed predicts death risk in adults with knee OA

Adults with, or at risk of, knee osteoarthritis (OA) who walk slower than 1.22 m/s in the present face an increased mortality risk, regardless of decline over the previous year, suggest the results of a study.

The authors used data from the Osteoarthritis Initiative and defined slow vs adequate walking speed as walking <1.22 vs ≥1.22 m/s on a 20 m walk test during the 12-month follow-up visit. Meaningful decline (yes/no) was defined as slowing ≥0.8 m/s over the past year.

At the 12-month visit, adequate sustainers were classified as those with adequate walking speed and no meaningful decline, slow sustainers as slow walking speed and no meaningful decline, adequate decliners as adequate walking speed and meaningful decline, and slow decliners as slow walking spend and meaningful decline.

The authors recorded mortality over 11 years. They also examined the association of walking speed with mortality using Cox regression, adjusted for potential confounders.

A total of 4,229 participants (mean age, 62±9 years; body mass index, 29±5 kg/m²; 58 percent female) were included in the analysis. Of these, 6 percent (n=270) died over 11 years.

Slow sustainers (hazard ratio [HR], 1.96, 95 percent confidence interval [CI], 1.44–2.66) and slow decliners (HR, 2.08, 95 percent CI, 1.46–2.96) had a twofold higher risk of mortality than adequate sustainers. Compared with adequate sustainers, adequate decliners had 0.43 times risk of mortality (HR, 0.57, 95 percent CI, 0.32–1.01).