Ferrante 2009.

Study characteristics
Methods	Retrospective cohort. Study period: 1998 to 2008
Participants	Country: Belgium. UC and unclassified IBD patients who underwent restorative proctocolectomy
Interventions	1. Preoperative infliximab (n= 22) within 12 weeks of surgery 2. Preoperative immunomodulators (n= 78) 3. Preoperative steroids(n= 64) 4. No preoperative infliximab (n= 119) 5. No preoperative immunomodulators (n= 63) 6. no preoperative steroids (n= 77)
Outcomes	Pouch sepcific complications, surgical site infections, and non‐surgical site infections within 30 days of surgery
Notes	NOS very high risk of bias overall Adjusted OR for preoperative steroids was obtained from multiv ariate model. Unadjusted ORs for preoperative infliximab and immunomodulators were obtained from univariate analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Representativeness of the exposed cohort	Low risk	Consecutive UC/IBDU patients who underwent restorative proctocolectomy from 1998 to 2008
Selection of the non exposed cohort	Low risk	Both groups obtained from the same hospital and time period
Ascertainment of exposure	Low risk	Clinical charts reviewed
Demonstration that outcome of interest was not present at start of study	Unclear risk	No information provided
Comparability of cohorts (Controlled for critical factor/other medications)	High risk	Univariate analysis
Comparability of cohorts (Controlled for additional factor)	High risk	Univariate analysis
Assessment of outcome	Low risk	Clinical charts reviewed
Was follow‐up long enough for outcomes to occur	Low risk	30 days
Adequacy of follow up of cohorts	Unclear risk	No information provided