Table 1:

Hospital, Patient, & Operation Characteristics

Hospital Characteristics (n=220)
SMR, mean (SD)	1.0 (0.3)
Teaching Hospital, n (%)	65 (29.6%)
Trauma L1 or L2, n (%)	48 (21.8%)
High tech capable, n (%)	152 (69.1%)
Rural Location, n (%)	20 (9.1%)
>=100 beds, n (%)	200 (90.9%)
Hospital EGS operative volume, mean (SD)	637.9 (368.8)
Patient Characteristics (n=140,333)++
Age in years, mean (SD) entire cohort	50.4 (19.8)
Age in years, mean (SD) by hospital	51.1 (4.9)
van Walraven score, mean (SD) entire cohort	2.3 (5.9)
van Walraven score, mean (SD) by hospital	2.5 (1.1)
Hospital length of stay in days, mean (SD) entire cohort	5.4 (7.9)
Hospital length of stay in days, mean (SD) by hospital	5.5 (1.1)
Male, n (%) entire cohort	58,960 (42.0%)
Proportion of male patients, mean (SD) by hospital	42.1% (4.4)
Operation Characteristics*
Appendectomy, hospital mean (SD); n=44,031	200.1 (125.2)
Cholecystectomy, hospital mean (SD); n=61,081	277.6 (177.5)
Colectomy, hospital mean (SD); n=11,469	52.1 (33.9)
Inguinal & Femoral Hernia, hospital mean (SD); n=3313	15.1 (10.2)
Lysis of Adhesion, hospital mean (SD); n=8403	38.2 (27.1)
Repair Perforated PUD, hospital mean (SD); n=2079	9.5 (5.6)
Small Bowel Resection, hospital mean (SD); n=6790	30.9 (19.8)
Ventral Hernia, hospital mean (SD); n=3167	14.4 (9.8)

⁺⁺Patient characteristics are listed two ways: First, for entire cohort, meaning at the individual level. Second, at the hospital level, which amounts to a mean of all hospital means. Of the 145,901 possible patients, 3 patients (0.002%) were excluded due to no hospital length of stay, and 5565 patients (3.8%) were excluded due to no gender specification.

^*Operative characteristics are average number of operations performed at a hospital over two years SMR, risk-standardized mortality ratio; SD, standard deviation; n, number; L1, level 1 trauma center; L2, level 2 trauma center; EGS, emergency general surgery; PUD, peptic ulcer disease (including gastric and duodenal perforations)