Table 4.

Associations Between Change in Symptoms and Tertiles of Averaged Daily Moderate-to-Vigorous Physical Activity Minutes.

Tertiles of daily moderate-to-vigorous physical activity
	Low (≤5 minutes)	Medium (6 – 19 minutes)	High (>19 minutes)	P-value for linear trend
Pain (Minimum clinically important difference: 1.2-4.6)**
Crude*	(Referent)	0.39 (−0.06 to 0.84)	0.56 (0.11 to 1.01)
Adjusted*§	(Referent)	0.51 (0.02 to 0.99)	0.71 (0.18 to 1.23)	0.01§
Stiffness (Minimum clinically important difference: 0.5-1.5)**
Crude*	(Referent)	0.04 (−0.19 to 0.26)	0.21 (−0.02 to 0.44)
Adjusted*¶	(Referent)	0.08 (−0.17 to 0.32)	0.22 (−0.05 to 0.49)	0.11¶
Physical Function (Minimum clinically important difference: 4.1-9.9)**
Crude*	(Referent)	1.41 (0.03 to 2.79)	1.65 (0.25 to 3.04)
Adjusted*┼	(Referent)	1.83 (0.32 to 3.34)	2.07 (0.38 to 3.76)	0.02┼

^*β coefficient (95% Confidence Interval (CI)).

^§Adjusted for age (linear term), gender, and SF-12 Physical Component Summary scores (estimates did not change if adjusted for individual items of PCS scores without physical functioning).

^¶Adjusted for age (linear term), gender, Kellgren-Lawrence grade, Charlson index, and SF-12 Physical Component Summary scores.

^┼Adjusted for age (linear term), gender, race/ethnicity, education, Body Mass Index, and SF-12 Physical Component Summary scores (estimates did not change if adjusted for individual items of PCS scores without physical functioning).

^**Positive beta coefficients corresponded to worsening symptoms and negative beta coefficients correspond to improved knee symptoms.