Table 2.

Primary and secondary outcomes of surgical site infection prevalence rates.

	Control surveillance			Intervention surveillance				Adjusted estimatesc
	SSIsa	Procedures	Unadjusted PRb	SSIsa	Procedures	Unadjusted PRb		PRR (95% CI)	p value
All SSIs	1171	148,365	0.79	781	89,339	0.87		1.10 (0.94–1.30)	0.25
Complex SSIsd	739	148,365	0.50	472	89,339	0.53		1.09 (0.89–1.34)	0.40
Superficial SSIs	432	148,365	0.29	309	89,339	0.35		1.26 (1.00–1.58)	0.070

PR = prevalence rate. PRR = prevalence rate ratio. SSI = surgical site infection.

^a214 SSIs that met present at time of surgery criteria were excluded, including 102 SSIs on the control arm (PR 0•07) and 112 SSIs on the intervention arm (PR 0.13).

^bPrevalence rates are given per 100 procedures performed.

^cModels included effects for time period and intervention phase, and models were adjusted for hospital, median wound class, median American Society of Anesthesiology score, and operation time score.

^dComplex SSIs included deep-incisional and organ/space SSIs.