Table 3.

Site characteristics for the study period May 2013–January 2015

Site	No. of enrolled patients	No. of participating surgeons
1	56	2
2	63	7
3	79	5
4	96	5
5	99	8
6	109	5
7	113	5
8	136	10
9	172	8
10	188	4
11	213	5
12	214	9
13	226	11
14	277	9
15	434	9