Table 4.

Estimated Differences (LSmean±SE, 95% Confidence Interval, p-value) in WOMAC Pain Levels (0–100%) Between Women and Men by KL Grade in Knees with PFOA and without PFOA.

KL Grade	Unadjusted*		Adjusted**		Adjusted***
+ PFOA
<2 n=160	6.2±2.6 (1.2–11.2)	0.0185	5.3±2.5 (0.4–10.1)	0.0408	3.9±2.5 (−0.9–8.7)	0.1282
2 n=248	9.3±2.7 (4.1–14.6)	0.0019	12.3±2.5 (7.5–17.2)	<0.0001	8.9±2.6 (3.8–14.0)	0.0019
3 n=238	9.8±2.9 (4.2–15.4)	0.0013	7.6±2.8 (2.2–13.0)	0.0075	6.3±2.8 (0.9–11.7)	0.0269
4 n=179	5.2±2.7 (−0.01–10.4)	0.0537	3.5±2.5 (−1.5–8.4)	0.1808	2.8±2.7 (−2.4–8.0)	0.3026
− PFOA
<2 n=3205	3.5±0.7 (2.2–4.7)	<0.0001	2.4±0.6 (1.2–3.6)	<0.0001	1.4±0.6 (0.2–2.5)	0.0214
2 n=604	3.1±1.6 (0.05–6.2)	0.0484	1.9±1.5 (−1.0–4.8)	0.2086	1.5±1.4 (−1.3–4.3)	0.2868
3 n=600	4.9±1.8 (1.4–8.4)	0.0064	2.4±1.6 (−0.7–5.6)	0.1384	1.4±1.6 (−1.7–4.5)	0.3681
4 n=190	3.2±2.8 (−2.4–8.7)	0.2716	0.5±2.6 (−4.6–5.6)	0.8460	0.1±2.5 (−4.9–5.0)	0.9836

BMI: Body Mass Index

KL: Kellgren-Lawrence

SE: Standard Error

PFOA: patellofemoral osteoarthritis

WOMAC: Western Ontario and McMaster Universities Osteoarthritis Index

^*Adjusted for contralateral knee KL grade and PFOA status

^**Adjusted for age, BMI, depression score, education, clinic site, race, comorbid conditions and analgesic medication use

^***Further adjusted for presence of widespread pain