Developing a risk stratification model for surgical site infection after abdominal hysterectomy

OBJECTIVE: The incidence of surgical site infection (SSI) ranges widely from 2-21% after hysterectomy. There is insufficient understanding of risk factors to build a specific risk stratification index. METHODS: Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from 7/1/03 - 6/30/05 at four institutions. SSIs were defined using CDC/NNIS criteria. Independent risk factors for abdominal hysterectomy were identified by logistic regression. RESULTS: There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSI after abdominal and 14 organ-space SSI after vaginal hysterectomy. Because risk factors for organ-space SSI were different in univariate analysis, further analyses focused on incisional SSI after abdominal hysterectomy. The maximum serum glucose within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI and lowest in uninfected patients (median 189, 156, and 141mg/dL, p = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio (OR) 2.4) and morbid obesity (body mass index (BMI) > 35, OR 5.7). Duration of operation > 75th percentile (OR 1.7), obesity (BMI 30-35, OR 3.0), and lack of private health insurance (OR 1.7) were marginally associated with increased odds of SSI. CONCLUSIONS: Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer operative time and lack of private health insurance were marginally associated with SSI. A specific risk stratification index could help to more accurately predict the risk of incisional SSI following abdominal hysterectomy

Enhanced surgical site infection surveillance following hysterectomy, vascular, and colorectal surgery

Objective.To evaluate the use of inpatient pharmacy and administrative data to detect surgical site infections (SSIs) following hysterectomy and colorectal and vascular surgery.Design.Retrospective cohort study.Setting.Five hospitals affiliated with academic medical centers.Patients.Adults who underwent abdominal or vaginal hysterectomy, colorectal surgery, or vascular surgery procedures between July 1, 2003, and June 30, 2005.Methods.We reviewed the medical records of weighted, random samples drawn from 3,079 abdominal and vaginal hysterectomy, 4,748 colorectal surgery, and 3,332 vascular surgery procedures. We compared routine surveillance with screening of inpatient pharmacy data and diagnosis codes and then performed medical record review to confirm SSI status.Results.Medical records from 823 hysterectomy, 736 colorectal surgery, and 680 vascular surgery procedures were reviewed. SSI rates determined by antimicrobial- and/or diagnosis code-based screening followed by medical record review (enhanced surveillance) were substantially higher than rates determined by routine surveillance (4.3% [95% confidence interval, 3.6%—5.1%] vs 2.7% for hysterectomies, 7.1% [95% confidence interval, 6.7%–8.2%] vs 2.0% for colorectal procedures, and 2.3% [95% confidence interval, 1.9%–2.9%] vs 1.4% for vascular procedures). Enhanced surveillance had substantially higher sensitivity than did routine surveillance to detect SSI (92% vs 59% for hysterectomies, 88% vs 22% for colorectal procedures, and 72% vs 43% for vascular procedures). A review of medical records confirmed SSI for 31% of hysterectomies, 20% of colorectal procedures, and 31% of vascular procedures that met the enhanced screening criteria.Conclusion.Antimicrobial- and diagnosis code-based screening may be a useful method for enhancing and streamlining SSI surveillance for a variety of surgical procedures, including those procedures targeted by the Centers for Medicare and Medicaid Services.</jats:sec

Use of Medicare claims to rank hospitals by surgical site infection risk following coronary artery bypass graft surgery

ObjectiveTo evaluate whether longitudinal insurer claims data allow reliable identification of elevated hospital surgical site infection (SSI) rates.DesignWe conducted a retrospective cohort study of Medicare beneficiaries who underwent coronary artery bypass grafting (CABG) in US hospitals performing at least 80 procedures in 2005. Hospitals were assigned to deciles by using case mix-adjusted probabilities of having an SSI-related inpatient or outpatient claim code within 60 days of surgery. We then reviewed medical records of randomly selected patients to assess whether chart-confirmed SSI risk was higher in hospitals in the worst deciles compared with the best deciles.ParticipantsFee-for-service Medicare beneficiaries who underwent CABG in these hospitals in 2005.ResultsWe evaluated 114,673 patients who underwent CABG in 671 hospitals. In the best decile, 7.8% (958/12,307) of patients had an SSI-related code, compared with 24.8% (2,747/11,068) in the worst decile ([Formula: see text]). Medical record review confirmed SSI in 40% (388/980) of those with SSI-related codes. In the best decile, the chart-confirmed annual SSI rate was 3.2%, compared with 9.4% in the worst decile, with an adjusted odds ratio of SSI of 2.7 (confidence interval, 2.2-3.3; [Formula: see text]) for CABG performed in a worst-decile hospital compared with a best-decile hospital.ConclusionsClaims data can identify groups of hospitals with unusually high or low post-CABG SSI rates. Assessment of claims is more reproducible and efficient than current surveillance methods. This example of secondary use of routinely recorded electronic health information to assess quality of care can identify hospitals that may benefit from prevention programs

Automated Detection of Infectious Disease Outbreaks in Hospitals: A Retrospective Cohort Study

Susan Huang and colleagues describe an automated statistical software, WHONET-SaTScan, its application in a hospital, and the potential it has to identify hospital infection clusters that had escaped routine detection

Graph showing survey-based Infection Control response by type of WHONET-SaTScan cluster.

<p>Significant differences among organism type and cluster size were noted when assessing the likelihood of triggering an intervention (Fisher exact tests). A trend toward a significant difference was found among cluster types. Among organism type, the likelihood of a cluster triggering an intervention was: gram-positive (43%), gram-negative (13%), fungal (14%). Among cluster size, the likelihood of a cluster triggering an intervention was: 2–5 (13%), 6–10 (45%), 10+ (44%). Among recurrence interval, the likelihood of a cluster triggering an intervention was: 365–999 (20%), 1,000–5,000 (20%), >5,000 (36%). Among cluster type, the likelihood of a cluster was: hospital (27%), antibiotic profile (12%), ward (38%), and service (50%).</p

Characteristics of detected clusters, 2002–2006.

a<p>Two clusters were identified by two different types of alerts.</p

Display of monthly nosocomial <i>A. baumanii</i> isolates.

<p>(A) Hospital-wide. (B) Restricted to isolates with an identical antibiotic susceptibility profile. Shaded area in gray indicates time period of cluster detection by WHONET-SaTScan.</p