Reported Surgical Site Infections Rates Research Articles

488 Surgical Site Infection After Hand Trauma Surgery in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Abstract Aim In low- and middle-income countries (LMICs) surgical site infections (SSIs) are the most common post-operative complication. Associated with increased morbidity and mortality, they impose a significant financial burden on patients. A recent meta-analysis found the overall SSI risk following hand trauma surgery is 5-10%. In this study a top-up-search and re-analysis was performed to establish SSI risk in the context of countries’ income classification. Method Our PRISMA-compliant systematic review searched MEDLINE, Embase, CINAHL, CENTRAL and clinicaltrials.gov to identify studies reporting SSI rates in adults undergoing hand or wrist surgeries for trauma. Studies were grouped by country-of-origin using World Bank income classifications. Meta-analysis of proportions was performed using R and risk of bias was evaluated. Results Of 11,056 screened s, 236 studies were included. None originated from low-income countries (LICs), 40 came from LMICs (16.9%), 48 from upper middle-income countries (UMICs) (20.3%) and 148 from high-income countries (HICs) (62.7%). Of LMIC studies, 70.0% were at high risk of bias, compared to 47.7% of UMIC and 31.1% of HIC studies. Meta-analysis demonstrated SSI risk in LMIC studies as 7.9% [95%CI 6.3-9.9], UMIC studies as 6.3% [95%CI 4.4-8.8] and HIC studies as 4.5% [95%CI 3.5-5.8]. Conclusions No studies were identified from LICs, perhaps indicative of the limited hand surgery capacity. Reduced research was found from MICs compared to HICs. We concluded that SSI risk following hand trauma appears lower in HICs compared to UMICs and LMICs but may be under-reported in MIC studies. Further research into hand trauma burden and outcomes in LMICs is required.

Outcomes of Two Different Negative Pressure Therapy Systems for Closed Incision Management in Knee and Hip Arthroplasty: A Systematic Review and Meta-Analysis.

Closed incision negative pressure therapy (ciNPT) has been adopted into practices of diverse surgical specialties to help reduce postsurgical complication risks. There are two primary commercially available systems that deliver ciNPT through different mechanisms. The purpose of this meta-analysis is to compare the potential effects of two different ciNPT systems on clinical outcomes following hip and knee arthroplasty. A systematic literature search was conducted to identify hip and knee arthroplasty studies comparing the incidence of surgical site infections (SSIs) and surgical site complications (SSCs) versus standard of care (SOC) following the use of two different ciNPT systems. Four meta-analyses were performed by calculating risk ratios (RR) to assess the effect of (1) ciNPT with foam dressing (ciNPT-F) versus SOC and (2) ciNPT with multilayer absorbent dressing (ciNPT-MLA) versus SOC. Comprehensive Meta-Analysis Version 3.0 (Biostat Inc., Englewood, NJ) software was used to perform the analyses. Twelve studies comparing ciNPT-F to SOC and six studies comparing ciNPT-MLAto SOC were analyzed. SSI rates were reported in seven of 12 studies involving ciNPT-F. In those, ciNPT-F significantly reduced the incidence of SSI (RR = .401, 95% confidence interval (CI) = .190, .844; p = .016). Across four of six studies that reported SSI rates, there was no significant difference in SSI rates between ciNPT-MLAvs SOC (RR = .580, 95% CI = .222, 1.513; p = .265). SSC rates were evaluated in eight of 12 ciNPT-F studies that reported SSC rates. This meta-analysis of the eight ciNPT-F studies showed significantly reduced SSC rates with ciNPT-F vs SOC (RR = .332, 95% CI = .236, .467; p < 0.001). For ciNPT-MLA, five of six studies reported SSC rates. In those, there was no significant difference in SSC rates between ciNPT-MLA vs SOC (RR = .798, 95% CI = .458, 1.398; p = .425). These meta-analyses results showed a significant reduction in SSI and SSC rates in the ciNPT-F group vs SOC and no difference in SSI and SSC rates in the ciNPT-MLA group vs SOC. The reasons for these observed differences were not evaluated as part of this study.Future controlled clinical studies comparing outcomes between different ciNPT systems over closed orthopedic incisions would help to validate these study results.

Irrigation techniques used in spine surgery for surgical site infection prophylaxis: a systematic review and meta-analysis

BackgroundThe greater likelihood of morbidity, mortality, length of hospital stays and poorer long-term outcomes as a result of surgical site infections secondary to spinal surgery makes prophylactic measures an imperative focus. Therefore, the aim of this review was to evaluate the available research related to the efficacy of different intraoperative irrigation techniques used in spinal surgery for surgical site infection (SSI) prophylaxis.MethodsWe performed a comprehensive search using Ovid Medline, EMBASE, Web of Science and the Cochrane library pertaining to this topic. Our meta-analysis was conducted according to PRISMA guidelines. The inclusion criteria consist of spine surgeries with intraoperative use of any wound irrigation technique, comparison groups with a different intraoperative irrigation technique or no irrigation, SSI identified with bacterial cultures or clinically in the postoperative period, reported SSI rates. Data extracted from eligible studies included, but was not limited to, SSI rates, irrigation technique and control technique. Exclusion criteria consist of articles with no human subjects, reviews, meta-analyses and case control studies and no details about SSI identification or rates. Pooled risk ratios were calculated. A meta-analysis was performed with a forest plot to determine risk estimates’ heterogeneity with I2 index, Q-statistic, and p value under a random-effects model. Funnel plot was used to assess publication bias. All databases were last checked on January, 2022. PROBAST tool was used to assess both risk of bias and applicability concerns.ResultsAfter reviewing 1494 titles and abstracts, 18 articles met inclusion criteria. They included three prospective randomized-controlled trials, 13 retrospective cohort studies, two prospective cohort studies. There were 54 (1.8%) cases of SSIs in the povidone-iodine irrigation group (N = 2944) compared to 159 (4.6%) in the control group (N = 3408). Using intraoperative povidone-iodine wound irrigation produced an absolute risk reduction of 2.8%. Overall risk ratio was 0.32 (95% CI 0.20–0.53, p < 0.00001). In a global analysis, study heterogeneity and synthesizing mostly retrospective data were primary limitations.ConclusionThe most evidence exists for povidone-iodine and has Level 2 evidence supporting SSI reduction during spinal surgery. Other antiseptic solutions such as dilute chlorhexidine lack published evidence in this patient population which limits the ability to draw conclusions related to its use in spinal surgery.Level of EvidenceII – Systematic Review with Meta-Analysis.

PIN155 Economic Burden of Surgical Site Infections in Turkey

Surgical site infections (SSI) are the most common hospital-acquired infection (HAI) and associated with increased morbidity, mortality and economic burden. The objective of this study was to estimate annual economic burden of SSIs for Turkish public and private hospitals. In the study 2 different SSI rates were considered: 4.3% (reported in the study of Leblebicioglu (2015), which are the findings of the International Nosocomial Infection Control Consortium (INICC)) and 0.7% (reported by National Health Service Related Infections Surveillance Network (USHIESA), Ministry of Health (MoH) (2018)). Annual surgery numbers reported by General Directorate of Healthcare Services, MoH were projected to 2020 by using compound annual growth rate between 2014-2018. Costs reported in the study of Çiftçi et al. (2005) were inflated to April 2020 by using consumer price index of Turkish Statistical Institute (TUIK). Overall number of SSI cases in Turkey was estimated to be 233,401 and 37,332 with INICC and USHIESA SSI rates respectively. Additional cost of SSI was estimated as 15,221 TL (2,220 USD). Overall economic burden of SSI for Turkey was estimated to be 3,552,593,239 TL (518,059,532 USD) and 568,234,186 TL (82,863,170 USD) with INICC and USHIESA SSI rates respectively in 2020. According to this study, economic burden of SSIs in Turkey was estimated for 2020. SSIs have significant economic burden on Turkish healthcare system as reported for Europe and USA. Given the discrepancies observed in reported SSI rates, it is proposed that more research on the topic is needed, as decision-makers need accurate and reliable data to generate insights and take appropriate action.

Using administrative data to determine rates of surgical site infections following spinal fusion and laminectomy procedures

Surgical site infections (SSIs) are a serious and costly post-op complication. Generating SSI rates often requires labor-intensive methods, but increasing numbers of publications reported SSI rates using administrative data. Index laminectomy and spinal fusion procedures were identified using Canadian Classification of Health Interventions (CCI) procedure codes for inpatients and outpatients in the province of Alberta, Canada between 2008 and 2015. SSIs occurring in the year postsurgery were identified using the International Classification of Diseases, 10th Revision, Canada (ICD-10-CA) diagnosis and CCI procedure codes indicative of post-op infection. Rates of SSIs and case characteristics were reported. Over the 8-year study period, 21,222 index spinal procedures were identified of which 12,027 (56.7%) were laminectomy procedures, with 322 SSIs identified, an SSI rate of 2.7 per 100 procedures. Of the 9,195 (43.3%) fusion procedures, 298 were identified as an SSI, an SSI rate of 3.2 per 100 procedures. This study found SSI rates increased from 2008 and 2015, and rates were the highest in the 0-18 year age group. The rates reported in this study were similar to published SSI rates using traditional surveillance methods, suggesting administrative data may be a viable method for reporting SSI rates following spinal procedures. Further work is needed to validate SSIs identified using administrative data by comparing to traditional surveillance.

Surgical Site Infections at a Level I Trauma Center in India: Data From an Indigenously Developed, e-SSI Surveillance System

Background: Globally, surgical site infections (SSIs) not only complicate the surgeries but also lead to $5–10 billion excess health expenditures, along with the increased length of hospital stay. SSI rates have become a universal measure of quality in hospital-based surgical practice because they are probably the most preventable of all healthcare-associated infections. Although, many national regulatory bodies have made it mandatory to report SSI rates, the burden of SSI is still likely to be significant underestimated due to truncated SSI surveillance as well as underestimated postdischarge SSIs. A WHO survey found that in low- to middle-income countries, the incidence of SSIs ranged from 1.2 to 23.6 per 100 surgical procedures. This contrasted with rates between 1.2% and 5.2% in high-income countries. Objectives: We aimed to leverage the existing surveillance capacities at our tertiary-care hospital to estimate the incidence of SSIs in a cohort of trauma patients and to develop and validate an indigenously developed, electronic SSI surveillance system. Methods: A prospective cohort study was conducted at a 248-bed apex trauma center for 18 months. This project was a part of an ongoing multicenter study. The demographic details were recorded, and all the patients who underwent surgery (n = 770) were followed up until 90 days after discharge. The associations of occurrence of SSI and various clinico-microbiological variables were studied. Results: In total, 32 (4.2%) patients developed SSI. S. aureus (28.6%) were the predominant pathogen causing SSI, followed by E. coli (14.3%) and K. pneumoniae (14.3%). Among the patients who had SSI, higher SSI rates were associated in patients who were referred from other facilities (P = .03), had wound class-CC (P &lt; .001), were on HBOT (P = .001), were not administered surgical antibiotics (P = .04), were not given antimicrobial coated sutures (P = .03) or advanced dressings (P = .02), had a resurgery (P &lt; .001), had a higher duration of stay in hospital from admission to discharge (P = .002), as well as from procedure to discharge (P = .002). SSI was cured in only 16 patients (50%) by 90 days. SSI data collection, validation, and analyses are essential in developing countries like India. Thus, it is very crucial to implement a surveillance system and a system for reporting SSI rates to surgeons and conduct a robust postdischarge surveillance using trained and committed personnel to generate, apply, and report accurate SSI data.Funding: NoneDisclosures: None

Postoperative Surgical Site Infections: Understanding the Discordance Between Surveillance Systems.

To characterize agreement in the ascertainment of surgical site infections (SSIs) between the National Surgical Quality Improvement Program (NSQIP), National Healthcare Safety Network (NHSN), and administrative data. The NSQIP, NHSN, and administrative data are the primary systems used to monitor and report SSIs for the purpose of quality control and benchmarking of hospitals and surgeons. These systems have different methods for identifying SSIs. We queried the NHSN, NSQIP, and administrative data systems for patients who had an operation at 1 of 4 hospitals within a single health system between January 2013 and September 2015. The detection of an SSI during a postoperative hospitalization was the outcome of analysis. Any SSI detected by one (or more) of these systems was analyzed by 2 reviewers to determine the presence of discrete elements of documentation constituting evidence of SSI. Concordance between the 3 systems (NHSN, NSQIP, and administrative data) was analyzed using Cohen's kappa. After application of appropriate exclusion criteria, a cohort of 9447 inpatient operations was analyzed. In total, 130 SSIs were detected by 1 or more of the 3 systems, with reported SSI rates of 0.5% (NHSN), 0.7% (administrative data), and 1.0% (NSQIP). Of these 130 SSIs, only 17 SSIs were reported by all 3 systems. The concordance between these 3 systems was moderate (kappa values NSQIP-NHSN = 0.50 [0.40-0.60], administrative-NHSN = 0.36 [0.24-0.47], and administrative-NSQIP = 0.47 [0.38-0.57]). Chart review found that reasons for discordance were related to issues of different criteria as well as inaccuracies. There is significant discordance in the determination of SSIs reported by the NHSN, NSQIP, and administrative data. The differences and limitations of each of these systems have to be recognized, especially when using these data for quality reports and pay for performance.

1235. A Survey of Surgical Site Infection (SSI) Surveillance Practices in US Hospitals, and their Association with SSI Rates

BackgroundCurrent US hospital reimbursement models rely on self-reported SSI rates. The impact of variability in SSI surveillance on publicly reported SSI rates is unknown.MethodsCross-sectional survey to US hospitals administered during November 18 – 2/19 through the Association for Professionals in Infection Control. We assessed SSI surveillance practices, and asked for self-reported facility standardized infection ratios (SIR) for hysterectomy and colon surgeries. We performed bivariate analysis and used Kendall’s ranks correlation for trend analysis.ResultsOf the 2,851 hospitals surveyed, 491 (17.2%) responded. Table 1 shows facility descriptors. Critical Access Hospitals (OR 6.11 [3.12 – 11.750, P < 0.005) and Ambulatory Surgical Centers (OR 3.92 [1.68 – 8.64], P < 0.001) were more likely to have less than one full-time ICP. University Hospitals were more likely to have ≥4 ICPs (OR 12.15 [6.73 – 22.04, P < 0.001). The majority (83%) of the 477 respondents reported electronic software for SSI surveillance, with Epic (23%), Theradoc (22%), and Cerner (11%) as the most common packages used. Manual surveillance was more likely for Critical Access Hospitals (OR 2.80 [1.47 – 5.19], P < 0.001). University Hospitals were more likely to have higher rates in 2016 for colon surgery (P = 0.02) and hysterectomy (P = 0.002). Table 2 shows characteristics of SSI surveillance practices reported by study participants. Ambulatory Surgical Center ICPs were more likely to use reports from surgeons and/or surgical staff as the initial trigger for SSI surveillance. University Hospital ICPs were significantly more likely to spend increased time (mean hours/month 69.77 vs. 28.99, P < 0.001), and to use more data sources for SSI review (mean 4.58 vs. 3.99, P = 0.001). In our trend analyses, we found the number of data sources used for SSI surveillance to be positively associated with higher SSI rates: (KT =0.14, P = 0.028 for colon SIR in 2017; KT = 0.20, P = 0.009; KT = 0.25, P = 0.001 for hysterectomy SIR in 2016 and 2017, respectively).ConclusionSSI surveillance practices across US hospitals vary significantly, and rigorous surveillance methods are associated with higher SSI rates. Standardizing SSI surveillance is necessary to accurately capture SSI burden of disease. Disclosures All authors: No reported disclosures.

Effects of Colorectal Surgery Classification on Reported Postoperative Surgical Site Infections

BackgroundCurrent procedural terminology (CPT) for colon and rectal surgery lacks procedural granularity and misclassification rates are unknown. However, they are used in performance measurement, for example, in surgical site infection (SSI). The objective of this study was to determine whether American College of Surgeons National Surgical Quality Improvement Program (NSQIP) abstraction methods accurately classify types of colorectal operations and, by extension, reported SSI rates. Materials and methodsThis was a retrospective study conducted at a single tertiary care center. The colectomy- and proctectomy-targeted NSQIP database from January 2011 to July 2016 was used to perform a semiautomated reclassification (SAR) of all colectomy and proctectomy cases performed by colorectal surgeons. The primary outcome was the difference in perioperative SSI rates by case classification method. ResultsThousand sixty-three patients underwent a colectomy or proctectomy during the study period with a mean age of 55.7 (SD = 16.7) years. Use of the NSQIP classification scheme resulted in 849 colectomy and 214 proctectomy cases. Use of the SAR method resulted in 650 colectomy cases and 413 proctectomy cases (P < 0.001), a 23.4% reclassification of colectomy cases. The group of cases classified as colectomy by SAR had a lower rate of deep/organ space infections than those classified as colectomy by NSQIP (4.5% versus 7.1%, P = 0.034). ConclusionsThese findings highlight the challenges of CPT code-based patient classification and subsequent outcomes analysis. Expanding the CPT system to more accurately represent colorectal operations would allow for more representative reported outcomes, thus enabling benchmarking and quality improvement.

Effectiveness of local vancomycin powder to decrease surgical site infections: a meta-analysis

Background contextSome surgeons use systemic vancomycin to prevent surgical site infections (SSIs), but patients who do not carry methicillin-resistant Staphylococcus aureus have an increased risk of SSIs when given vancomycin alone for intravenous prophylaxis. Applying vancomycin powder to the wound before closure could increase the local tissue vancomycin level without significant systemic levels. However, the effectiveness of local vancomycin powder application for preventing SSIs has not been established. PurposeOur objective was to systematically review and evaluate studies on the effectiveness of local vancomycin powder for decreasing SSIs. Study designMeta-analysis. SampleWe included observational studies, quasi-experimental studies, and randomized controlled trials of patients undergoing surgical procedures that involved vancomycin powder application to surgical wounds, reported SSI rates, and had a comparison group that did not use local vancomycin powder. Outcome measuresThe primary outcome was postoperative SSIs. The secondary outcomes included deep incisional SSIs and S. aureus SSIs. MethodsWe performed systematic literature searches in PubMed, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials via Wiley, Scopus (including EMBASE abstracts), Web of Science, ClinicalTrials.gov, BMC Proceedings, ProQuest Dissertation, and Thesis in Health and Medicine, and conference abstracts from IDWeek, the Interscience Conference on Antimicrobial Agents and Chemotherapy, the Society for Healthcare Epidemiology of America, and the American Academy of Orthopedic Surgeons annual meetings, and also the Scoliosis Research Society Annual Meeting and Course. We ran the searches from inception on May 9, 2013 with no limits on date or language. After reviewing 373 titles or abstracts and 22 articles in detail, we included 10 independent studies and used a random-effects model when pooling risk estimates to assess the effectiveness of local vancomycin powder application for preventing SSIs, the outcome of interest. We used the I2-index, Q-statistic, and corresponding p value to assess the heterogeneity of the risk estimates, and funnel plots to assess publication bias. ResultsWe included seven quasi-experimental studies, two cohort studies, and one randomized controlled trial, encompassing 5,888 surgical patients. The pooled effects showed that applying local vancomycin powder was significantly protective against SSIs (pooled odds ratio [pOR] 0.19; 95% confidence interval [CI] 0.09–0.38), deep incisional SSIs (pOR 0.23; 95% CI 0.09–0.57), and SSIs caused by S. aureus (pOR 0.22; 95% CI 0.08–0.58). However, significant heterogeneity was present for studies evaluating all SSIs or deep incisional SSIs. When we pooled the risk estimates from the eight studies that assessed patients undergoing spinal operations, vancomycin powder remained significantly protective against SSIs (pOR 0.16; 95% CI 0.09–0.30), deep incisional SSIs (pOR 0.18; 95% CI 0.09–0.36), and SSIs caused by S. aureus (pOR 0.11; 95% CI 0.03–0.36). The pooled ORs from studies of spinal operations were lower than those for all studies and the estimates from spinal operation studies were homogeneous. However, there was evidence of publication bias. ConclusionsLocal administration of vancomycin powder appears to protect against SSIs, deep incisional SSIs, and S. aureus SSIs after spinal operations. Large, high-quality studies should be performed to evaluate this intervention before it is used routinely.

A benchmark too far: findings from a national survey of surgical site infection surveillance

The national surgical site infection (SSI) surveillance service in England collates and publishes SSI rates that are used for benchmarking and to identify the prevalence of SSIs. However, research studies using high-quality SSI surveillance report rates that are much higher than those published by the national surveillance service. This variance questions the validity of data collected through the national service. To audit SSI definitions and data collection methods used by hospital trusts in England. All 156 hospital trusts in England were sent questionnaires that focused on aspects of SSI definitions and data collection methods. Completed questionnaires were received from 106 hospital trusts. There were considerable differences in data collection methods and data quality that caused wide variation in reported SSI rates. For example, the SSI rate for knee replacement surgery was 4.1% for trusts that used high-quality postdischarge surveillance (PDS) and 1.5% for trusts that used low-quality PDS. Contrary to national protocols and definitions, 10% of trusts did not provide data on superficial infections, 15% of trusts did not use the recommended SSI definition, and 8% of trusts used inpatient data alone. Thirty trusts did not submit a complete set of their data to the national surveillance service. Unsubmitted data included non-mandatory data, PDS data and continuous data. The national surveillance service underestimates the prevalence of SSIs and is not appropriate for benchmarking. Hospitals that conduct high-quality SSI surveillance will be penalized within the current surveillance service.

Developing a Risk Stratification Model for Surgical Site Infection after Abdominal Hysterectomy

The incidence of surgical site infection (SSI) after hysterectomy ranges widely from 2% to 21%. A specific risk stratification index could help to predict more accurately the risk of incisional SSI following abdominal hysterectomy and would help determine the reasons for the wide range of reported SSI rates in individual studies. To increase our understanding of the risk factors needed to build a specific risk stratification index, we performed a retrospective multihospital analysis of risk factors for SSI after abdominal hysterectomy. Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from July 1, 2003, to June 30, 2005, at 4 institutions. SSIs were defined by using Centers for Disease Control and Prevention/National Nosocomial Infections Surveillance criteria. Independent risk factors for abdominal hysterectomy were identified by using logistic regression. There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSIs after abdominal hysterectomy and 14 organ-space SSIs after vaginal hysterectomy. Because risk factors for organ-space SSI were different according to univariate analysis, we focused further analyses on incisional SSI after abdominal hysterectomy. The maximum serum glucose level 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 141 mg/dL, respectively; 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 greater than the 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. Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer duration of operation and lack of private health insurance were marginally associated with SSI.

Two years of surgical site infection surveillance in Western Australia: analysing variation between hospitals

Surgical site infections (SSIs) following hip and knee arthroplasty are significant adverse events. The aim of this study was to present the first 2 years of aggregated and hospital-based SSI rates from the Healthcare Infection Surveillance Western Australia (HISWA) surveillance system. HISWA collects risk-adjusted data based on standardised collection methodologies and definitions. In total, 4131 hip and 4858 knee procedures were monitored at 10 public and private hospitals. There were significant variations in reported SSI rates following arthroplasty at WA hospitals (mean 1.82, range 0.67–3.83 SSIs per 100 hip procedures; mean 1.5, range 0.47– 3.67 SSIs per 100 knee procedures). Funnel plots identified hospitals with significantly high and low SSI rates, in particular hospitals with high operative volumes and significantly better outcomes. Significant variation was observed when analysis was performed by operative volume, United States National Nosocomial Infection Surveillance (NNIS) risk group and infection type (deep/organ space v. superficial). Investigations did not reveal marked differences in surveillance methodology between sites, but other causes of variation, including patient factors that are not incorporated in NNIS risk indexation, surgeon procedure volume and differences in SSI prevention policy and practice, need further evaluation. The policy implications of the association between operative volume and SSI rate merits further discussion in Australia.

Surgical Volume and the Risk of Surgical Site Infection in Community Hospitals

To determine if surgical volume affects the risk of surgical site infections (SSI) in community hospitals. The utility of public reporting and the optimal methods to employ when reporting SSI rates remain controversial and contentious issues. Studies examining the association between surgical volume and SSI risk have included few community hospitals and have reported conflicting results. A prospective study of surgical procedures performed at 18 community hospitals from January 1, 2004 to December 31, 2005, was performed. Hospitals were separated based on average surgical volume per year: small (<1500 procedures), medium (1500 < or = procedures < 4000), and large (> or =4000 procedures). The risk of SSI for each category was determined using multivariable Poisson regression. Prospective surveillance identified 1434 SSIs after 132,111 surgical procedures (prevalence rate = 1.09/100 procedures). In unadjusted analysis, the risk of SSI was almost twice as high at small hospitals [prevalence rate ratio (PRR) = 1.9 (95% CI 1.78-2.05)] and large hospitals [PRR = 1.79 (95% CI 1.70-1.90)] compared with medium hospitals. After adjusting for differences between hospital category and important confounders, the risk of SSI at small hospitals was still 1.5 times higher than medium hospitals [adjusted PRR = 1.49 (95% CI 1.39-1.60)], whereas the risk at large hospitals was substantially decreased compared with medium hospitals [adjusted PRR = 1.29 (95% CI 1.22-1.36)]. The relationship between hospital surgical volume and rates of SSI in community hospitals is important and complex. As public reporting of SSI rates expands, improved methods for risk-adjusting infection rates are needed.

Surgical site infection (SSI) rates after pediatric spine (PS) surgery: Is underlying diagnosis (UD) a predictor of infection (POI)?

ISSUE: We have tracked SSI rates in PS patients at this university-affiliated hospital since 1995. From 1995 to 2000, we successfully decreased our overall infection rate 58.5% (from 12.23% to 5.11%). In 2001, we noted a small increase, and by 2002, our SSI rate had increased almost threefold to 13.8%. During 2003, traditional interventions only reduced the rate to 11.8%. PROJECT: Increased emphasis on patient safety led us to intensify our efforts during 2004. At the 1991 meeting of the Pediatric Orthopaedic Society of North America, Kretzler reported SSI rates of 11% in patients with cerebral palsy (CP) and spina bifida (SB) compared to 1% for those with idiopathic scoliosis (IS). We looked at our cases and infections based on UD with the intent of altering our interventions if indicated. Using discharge diagnosis (ICD-9) codes, we were able to divide our cases into the following categories: IS (including kyphosis), genetic disorders, neurological disorders (ND) (including CP, SB, and muscular dystrophy), and other. To facilitate decisions regarding interventions, we looked at depth of infection and infecting organism group as it related to UD. RESULTS: Of our cases, 62.2% had an underlying diagnosis of IS; 15.5% were ND; 3.5% were genetic, and 18.8% were other. The patients ranged in age from less than 1 year to 18 years; 66% were between ages 12 and 16. Our infection rates were 19% in our ND patients; 12.8% in our genetic patients, and 8.8% in our IS patients. We performed a multivariate analysis using logistic regression which showed that three variables were predictors of infection: being Black (versus Caucasian) (risk ratio [RR]=1.9, p=0.006) and having UD of either CP (RR 2.0, p=0.02) or SB (RR 4.2, p < 0.001). Our analysis showed that 37.5% of the deep SSIs occurred in our ND patients, 33.3% in IS, and 29.2% in other. SSI organisms in ND patients were 20.9% gut flora compared to IS patients which were 19.1% (p=0.05). LESSONS LEARNED: Our overall infection rate was higher for patients with underlying diagnosis of ND compared to those with IS. We were surprised to discover that race was a risk factor and further exploration of this variable is warranted. Based upon the findings related to infecting organisms, we will be looking at new interventions that address incontinence pre- and post-operatively as well as antibiotic prophylaxis that provides better coverage against enteric organisms such as a second-generation cephalosporin.

Six Years of Surgical Wound Infection Surveillance at a Tertiary Care Center

(1) Antibiotic restriction policies result in alteration of microbiologic features of surgical site infections (SSIs) and (2) reported SSI rates are underestimated when postdischarge surveillance is not included in SSI surveillance efforts. Retrospective analysis of prospectively collected SSI surveillance data. We compared initial microbial isolates from SSIs between (1) January 1, 1993, and December 31, 1995, and (2) January; 1, 1996, and December 31, 1998. Antibiotic restriction policies were implemented at Fairview-University Medical Center, Minneapolis, Minn, on March 1, 1995. For the combined periods (January 1, 1993, to December 31, 1998), we determined SSI rates for 20007 operations according to the extent of bacterial contamination at surgery (wound class). Then, we analyzed SSI rates for 10559 of these operations (selected based on availability of Anesthesia Society of America score and type of procedure) using the surgical wound risk index (wound class, Anesthesia Society of America score, and length of operation). We categorized SSI rates by 17 procedures for comparison with SSI rates reported by 286 hospitals that contributed data confidentially and voluntarily to the National Nosocomial Infections Surveillance System in 1998. We compared SSI rates with and without postdischarge surveillance. Coagulase-negative staphylococcus and group D enterococcus were the 2 most frequent isolates before and after antibiotic restriction policies were implemented. Candida albicans isolates decreased from 7.9% (1993-1995) to 6.5% (1996-1998; P=.46). Methicillin-resistant Staphylococcus aureus (1.8% of isolates) and vancomycin-resistant enterococcus (2.4% of isolates) organisms were first identified between 1996 and 1998. Our SSI rates were 2.6% for class I wounds, 3.6% for class II wounds, and 10.5% for class III/IV wounds; 53.9% of SSIs were identified after hospital discharge. Antibiotic restriction policies did not alter the microbial spectrum of SSIs during the observation period. Reporting SSI rates in the absence of postdischarge surveillance dramatically underestimates actual SSI rates, especially in tertiary care hospitals that provide care for large populations of elderly and immunosuppressed patients.

Outcomes of a postdischarge surveillance system for surgical site infections at a Midwestern regional referral center hospital

Background: Postdischarge surveillance has been reported in the literature as one method for detecting surgical site infections (SSIs) that more traditional methods of surveillance (review of readmission data, monitoring of microbiology, radiology, pharmacy antibiotic usage reports, and medical record review) fail to include. Methods: This article describes a postdischarge surveillance program that used surgeon questionnaires and was implemented at a 225-bed Midwestern regional referral center hospital. Evaluation of the postdischarge program was accomplished by review of infection control program data for calendar years 1995 through 1997. Results: Implementation of the postdischarge program resulted in an almost fourfold increase (in both 1995 and 1996) in SSI rates over the reported SSI rates if only traditional surveillance methods had been used. A majority of surgeons (79% in 1995 and 83% in 1996) had individual response rates of 80% or greater. In addition, implementation of the postdischarge program required only 3.5 to 4 additional hours per month. Conclusions: Results suggest that the postdischarge surveillance program identified SSIs missed by traditional surveillance methods, resulted in higher reported rates of SSI, was moderately to well accepted by surgeons, and was implemented with a minimum of organizational resources. (AJIC Am J Infect Control 1999;27:158-64)