1. Medical adverse events.

Event	Number of studies*	Routine‐testing group	No‐testing group	Odds ratio (95% confidence interval)
		Number of events (n)	Number of events (n)
Overall
Total	3	353	354	1.00 (0.86, 1.16)
Death	3	1	2	0.50 (0.05, 5.52)
Hospitalization	1	28	33	0.85 (0.51, 1.40)
Intraoperative: day of surgery, prior to discharge
Total	3	242	238	1.02 (0.85, 1.22)
Death	3	0	0	N/A
Hospitalization	1	3	5	0.60 (0.14, 2.51)
Postoperative: during study follow‐up period after discharge
Total	2	116	121	0.96 (0.74, 1.24)
Death	2	1	2	0.50 (0.05, 5.52)
Hospitalization	1	25	30	0.83 (0.49, 1.42)

*Event reported by three studies (routine‐testing group: n = 10,764; no‐testing group: n = 10,767); event reported by two studies: Cavallini 2004 and Schein 2000 (routine‐testing group: n = 10,262; no‐testing group: n = 10,264); event reported by one study: Schein 2000 (routine‐testing group: n = 9624; no‐testing group: n = 9626).