Table 3

Differences in mean patient-reported outcome measures by arthroplasty group.

Patient-Reported Outcome Measure	No Arthroplasty (Mean ± SD)	P Value^{^a}	Arthroplasty (Mean ± SD)	P Value^{^a}	P Value^{^b}
Oswestry Disability Index
Preoperative	42.5 ± 16.8	-	39.8 ± 13.9	-	0.424
6 wk	35.8 ± 19.3	<0.001	35.4 ± 19.8	0.145	0.928
12 wk	29.6 ± 18.4	<0.001	25.2 ± 22.6	0.002	0.323
6 mo	24.9 ± 19.6	<0.001	19.2 ± 18.7	<0.001	0.226
1 y	23.3 ± 21.7	<0.001	25.4 ± 23.8	0.005	0.736
2 y	23.4 ± 22.0	<0.001	34.9 ± 33.8	0.177	0.167
12-Item Short Form Physical Component Summary
Preoperative	30.8 ± 8.9	-	30.4 ± 8.0	-	0.850
6 wk	31.6 ± 8.7	0.079	34.1 ± 9.7	0.149	0.238
12 wk	35.4 ± 10.1	<0.001	40.0 ± 11.0	0.005	0.063
6 mo	39.3 ± 11.7	<0.001	39.9 ± 11.3	<0.001	0.831
1 y	40.5 ± 12.0	<0.001	42.6 ± 12.0	0.001	0.484
2 y	41.6 ± 11.7	<0.001	37.0 ± 13.8	0.261	0.245
Patient-Reported Outcomes Measurement Information System Physical Function
Preoperative	35.1 ± 6.4	-	37.7 ± 6.5	-	0.171
6 wk	37.2 ± 6.4	0.001	40.1 ± 6.0	0.031	0.141
12 wk	40.8 ± 6.8	<0.001	42.8 ± 8.9	0.020	0.297
6 mo	44.3 ± 7.2	<0.001	41.7 ± 9.7	0.064	0.271
1 y	44.7 ± 9.1	<0.001	47.5 ± 11.7	0.009	0.302
2 y	45.0 ± 9.3	<0.001	47.7 ± 9.2	0.018	0.374
VAS back
Preoperative	6.6 ± 2.4	-	5.5 ± 2.5	-	0.029
6 wk	4.0 ± 2.5	<0.001	3.1 ± 2.2	0.003	0.132
12 wk	3.6 ± 2.6	<0.001	3.6 ± 3.0	0.172	0.991
6 mo	3.4 ± 2.7	<0.001	2.5 ± 2.7	0.001	0.133
1 y	3.2 ± 2.9	<0.001	2.6 ± 2.8	0.009	0.933
2 y	3.4 ± 2.8	<0.001	3.9 ± 3.5	0.099	0.781
VAS leg
Preoperative	5.8 ± 2.8	-	5.7 ± 2.1	-	0.780
6 wk	3.2 ± 2.9	<0.001	3.5 ± 2.8	0.003	0.706
12 wk	2.8 ± 2.7	<0.001	3.0 ± 3.2	0.002	0.703
6 mo	2.7 ± 2.8	<0.001	2.7 ± 2.9	0.001	0.992
1 y	2.7 ± 3.0	<0.001	3.4 ± 3.1	0.009	0.390
2 y	2.4 ± 2.8	<0.001	3.6 ± 3.6	0.104	0.262

Abbreviation: VAS, visual analog scale.
Note: Boldface indicates statistical significance.
↵a P values calculated using paired t test.
↵b P values calculated using linear regression.