Preoperative anxiety and depression predict two-year outcomes after total hip or knee arthroplasty

Table 3 Comparison of preoperative and postoperative pain Visual Analogue Scale scores between the two groups (mean ± SD, points)¹

Pain state	Group	n	Preoperative	1 year postoperative	2 years postoperative
At rest	Exposed group	92	4.8 ± 1.6	1.8 ± 0.9	1.5 ± 0.8
	Non-exposed group	92	4.7 ± 1.5	1.2 ± 0.7	0.9 ± 0.6
	t-value		0.432	4.986	5.437
	P value		0.666	< 0.001	< 0.001
During activity	Exposed group	92	6.9 ± 1.8	2.6 ± 1.1	2.2 ± 1.0
	Non-exposed group	92	6.8 ± 1.7	1.7 ± 0.9	1.3 ± 0.8
	t-value		0.379	5.974	6.526
	P value		0.705	< 0.001	< 0.001

¹Simple effect analysis showed that between-group differences were mainly reflected at the 1-year and 2-year postoperative time points. Repeated measures ANOVA showed that the time effect, between-group effect, and interaction effect were all statistically significant.

VAS: Visual Analogue Scale.