Variability in infection surveillance methods and impact on surgical site infection rates

Background: The impact of variability in infection surveillance methodologies on publicly reported rates of surgical site infection (SSI) is not well defined.

Methods: We performed a cross-sectional study to assess infection preventionists' surveillance practices across acute care US hospitals. We collected self-reported annual facility standardized infection ratios for colon surgery and abdominal hysterectomy as provided by the National Healthcare Safety Network. Trend analysis using Kendall's rank correlation evaluated the association between surveillance rigor and SSI rates.

Results: Among 492 participating hospitals, 63%, 15%, 13%, and 8% were community, university-affiliated, critical access, and ambulatory surgical centers, respectively. Most critical access hospitals (82%) and ambulatory surgical centers (98%) reported less than one full time infection preventionists (P ≤ .001). University-affiliated medical centers spent significantly more time and used more data sources for monthly SSI review compared with other hospitals. Critical access hospitals and ambulatory surgical centers were more likely to rely on manual surveillance only (P < .001). The number of different data sources used for SSI surveillance was positively associated with higher SSI rates: (K_T 0.14, P = .028 for colon SSI in 2017; K_T 0.20, P = .009 for hysterectomy SSI in 2016; K_T 0.25, P = .001 for hysterectomy SSI in 2017).

Conclusions: Rigorous SSI surveillance using more data sources for case-finding is more likely to be associated with higher facility SSI rates for colon surgery and abdominal hysterectomy.