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

Table 2 Comparison of preoperative and postoperative joint function scores between the two groups (mean ± SD, points)¹

Surgery type	Group	n	Preoperative	1 year postoperative	2 years postoperative	F time	P time	F between-groups	P between-groups	F interaction	P interaction
THA (Harris Score)	Exposed group	52	46.3 ± 8.5	78.4 ± 9.2	82.6 ± 8.7	486.32	< 0.001	18.74	< 0.001	6.85
	Non-exposed group	53	47.1 ± 8.2	85.7 ± 7.4	89.3 ± 6.9
	t-value		0.485	4.526	4.389
	P value		0.629	< 0.001	< 0.001
TKA (HSS Score)	Exposed group	40	48.6 ± 9.3	76.2 ± 8.6	80.8 ± 8.3	412.67	< 0.001	15.28	< 0.001	5.92	0.004
	Non-exposed group	39	49.2 ± 8.9	83.4 ± 7.2	87.1 ± 7.5
	t-value		0.295	4.058	3.546
	P value		0.769	< 0.001	0.001

¹P-values for between-group comparisons at postoperative time points have been Bonferroni-corrected (since two time points were compared - 1 year and 2 years postoperatively - the correction factor is 2, with adjusted α level of 0.025).

THA: Total hip arthroplasty; TKA: Total knee arthroplasty; HSS: Hospital for Special Surgery.