Figure 2.

NHANES frequent knee pain and KOOS₄ at 2 years, according to radiographic osteoarthritis status

(A) NHANES frequent knee pain at 2 years in the 53 participants in the 2-year dataset also undergoing knee x-ray at 2 years. The percentage of patients reporting NHANES frequent knee pain for each category are printed above the relevant column. Fisher's exact test to test 2 × 2 contingency for no osteoarthritis versus new osteoarthritis, in the presence or absence of NHANES symptoms, showed no significant difference (two-sided test, p=0·20). Fisher's exact test to test 2 × 2 contingency for no progression versus progression or new osteoarthritis, in presence or absence of NHANES symptoms, showed no significant difference (two-sided test, p>0·99). (B) KOOS₄ at 2 years in the 52 study participants in the 2-year dataset also undergoing knee x-ray at 2 years. The Kruskal Wallis test to test for differences between groups showed no significant difference (p=0·69). KOOS₄=Knee Injury and Osteoarthritis Outcome Score based on a composite of four subscales (pain, symptoms, sports and recreation, and quality of life).NHANES=National Health and Nutrition Examination Survey. *No evidence of radiographic osteoarthritis at baseline or 2 years. †New radiographic osteoarthritis (Kellgren and Lawrence grade for osteoarthritis [KLG] ≥2) at 2 years (new osteoarthritis). ‡Evidence of KLG 1 or more at baseline with no progression (no progression). §This category includes new osteoarthritis (as previously defined) or progression (progression of at least 1 grade on KLG, where KLG is 1 or more at baseline).