Table 3. Physical activity and health-related quality of life measures across knee status categories.

	Non-OA (Pain-/ROA-) (Weighted n = 8,131,884)	Pain only (Pain+/ROA-) (Weighted n = 1,093,947)	ROA only (Pain-/ROA+) (Weighted n = 2,819,587)	Painful ROA (Pain+/ROA+) (Weighted n = 1,641,640)	P value
Activity limitation					< 0.001
Yes, %	11.7	28.9	13.3	36.9
No, %	88.9	71.1	86.7	63.1
Cause of activity limitation					< 0.001
Arthralgia	0.6	9.6	1.5	22.7
Other	99.4	90.4	98.5	77.3
Mobility					< 0.001
I have no problems walking	86.1	51.4	74.1	26.3
I have moderate problems walking	13.4	45.5	25.4	68.7
I am unable to walk	0.5	3.1	0.5	5.0
Self-care					< 0.001
I have no problems washing or dressing myself	95.1	85.1	94.6	77.4
I have moderate problems washing or dressing myself	4.7	13.6	5.2	20.6
I am unable to wash or dress myself	0.2	1.3	0.2	2.0
Usual activities					< 0.001
I have no problems doing my usual activities	91.1	66.1	98.6	53.3
I have moderate problems doing my usual activities	8.2	29.8	10.5	39.6
I am unable to do my usual activities	0.7	4.1	1.9	7.1
Pain/discomfort					< 0.001
I have no pain or discomfort	78.2	41.9	77.4	30.9
I have moderate pain or discomfort	20.1	47.2	20.3	52.1
I have extreme pain or discomfort	1.7	10.9	2.3	17.0
Anxiety/ depression					< 0.001
I am not anxious or depressed	88.4	70.2	89.6	74.5
I am moderately anxious or depressed	11.1	26.1	9.9	22.1
I am extremely anxious or depressed	0.6	3.7	0.5	3.4
EQ-VAS score	73.72 ± 0.35	60.99 ± 1.06	72.21 ± 0.56	59.70 ± 0.92	< 0.001
EQ-5D index	0.94 ± 0.00	0.82 ± 0.01	0.92 ± 0.00	0.76 ± 0.01	< 0.001

Overall P-values were provided for the overall effects of clinical characteristics on the OA categories.