Procedure-specific surgical site infection rates and postdischarge surveillance in Scotland

To investigate the impact of postdischarge surveillance (PDS) on surgical-site infection (SSI) rates for selected surgical procedures in acute care hospitals in Scotland.

Prospective surveillance of SSI after selected surgical procedures.

The Scottish Surveillance of Healthcare Associated Infection Programme (SSHAIP), which is based on the methodology of the Centers for Disease Control and Prevention (CDC) National Nosocomial Infections Surveillance system (NNIS). Thirty-two of 46 acute care hospitals throughout Scotland contributed data to SSHAIP for this study.

Data were from 21,710 operations that took place between April 1, 2002, and June 30, 2004; nine categories of surgical procedures were analyzed. CDC NNIS system definitions and methods were used for SSI PDS. PDS is a voluntary component of the mandatory SSI surveillance program in Scotland. PDS was categorized as none, passive, active without direct observation, and active with direct observation.

From our study information, PDS data were available for 12,885 operations (59%). A total of 2,793 procedures (13%) were associated with passive PDS and 10,092 (46%) with active PDS. The SSI rate among the 8,825 operations with no PDS was 2.61% (95% confidence interval [CI], 2.3%-3.0%), which was significantly lower than the SSI rate found among the 12,885 operations for which PDS was performed (6.34% [95% CI, 5.9%-6.8%]). For breast surgery, cesarean section, hip replacement, and abdominal hysterectomy, the rate of SSI when PDS was performed was significantly higher than that when PDS was not performed (P<.01 for each procedure). No differences in SSI rates were found for surgery to repair fractured neck of the femur or for knee replacement. SSI rates were examined according to procedure type, performance of PDS, and NNIS risk index; rates of SSI increased with NNIS risk index within procedure group and PDS group. Logistic regression analyses confirmed that procedure type, performance of PDS, and NNIS risk index were all statistically independent predictors of report of an SSI (P<.05).

This Scottish national data set incorporates a substantial amount of PDS data. We recommend a procedure-specific approach to PDS, with direct observation of patients after breast surgery, cesarean section, and hysterectomy, for which the length of stay is typically short. Readmission surveillance may be adequate to detect most SSIs after orthopedic surgery or vascular surgery, for which the length of stay is typically longer.