Table 2.

Summary of findings

Outcome	Studies	Hips	Risk ratio	Significance
Postoperative surgical site infection	8	200,950	1.25 CI [1.01, 1.55]	0.04
Cost of surgery	6	129,893	3.44 CI [2.57, 4.30]	< 0.00001
Postoperative length of hospital Stay	9	232,691	0.83 CI [0.48, 1.18]	< 0.00001
Complications during index hospitalization	5	36,159	0.90 CI [0.49, 1.64]	0.73
Complication within 90 days post-op	3	74,409	1.80 CI [1.50, 2.17]	< 0.00001
Revision arthroplasty within 1 year post-op	5	361,440	1.27 CI [0.98, 1.65]	0.07
Long-term revision arthroplasty	5	509,155	1.18 CI [0.86, 1.62]	0.31
30-day mortality	3	140,656	2.33 CI [1.27, 4.28]	0.006
90-day mortality	4	58,688	1.26 CI [1.05, 1.51]	0.01
1-year mortality	4	13,203	2.26 CI [1.32, 3.88]	0.003
Postoperative thromboembolic events	5	147,015	1.28 CI [0.92, 1.77]	0.15

CI confidence interval

*Risk ratio for low-volume hospitals in comparison to high-volume hospitals