Table 2.

The association between patterns of knee pain and self-reported symptomatic knee osteoarthritis on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscale summary scores.

KOOS Subscales	Patellofemoral Pain vs. Tibiofemoral Pain^†	Combined Pain vs. Tibiofemoral Pain^†	Combined Pain vs. Patellofemoral Pain^†

Pain
Odds Ratio (95% Cl)^a	0.89 (0.72, 1.11)	1.64 (1.25, 2.13)^*	1.82 (1.35, 2.44)^*
Group Percentages	57.5% vs. 61.0%	73.4% vs. 61.0%	73.4% vs.58.0%

Symptoms
Odds Ratio (95% Cl)^a	0.89 (0.71, 1.11)	1.54 (1.19, 2.00)^*	1.72 (1.28, 2.38)^*
Group Percentages	49.3% vs. 52.3%	64.4% vs. 52.3%	64.4% vs. 49.3%

Activities of Daily Living
Odds Ratio (95% Cl)^a	0.85 (0.22, 3.23)	2.56 (0.81, 8.33)	3.03 (0.72, 12.50)
Group Percentages	0.6% vs. 0.5%	1.8% vs. 0.5%	1.8% vs. 0.6%

Function, Sports, and Recreational Activities
Odds Ratio (95% Cl)^b	0.81 (0.61, 1.08)	1.56 (1.08, 2.22)^*	1.92 (1.27, 2.86)^*
Group Percentages	74.3% vs. 78.5%	86% vs. 78.5%	86.0% vs. 74.3%

Quality of Life
Odds Ratio (95% Cl)^b	1.15 (0.76, 1.75)	2.38 (1.28, 4.35)^*	2.08 (1.04, 4.17)^*
Group Percentages	91.6% vs. 91.0%	96% vs. 91.0%	96.0% vs. 91.6%

Generalized linear mixed models, adjusted for age, gender, race, body mass index, clinical center, and radiographic disease severity.

Generalized linear models, adjusted for age, gender, race, body mass index, clinical center, and radiographic disease severity.

^†

Reference group for comparisons

Significantly different than the reference group (P < 0.05)