To investigate whether comparison by deep or adjusted deep surgical site infection (SSI) rates in orthopedic surgeries are a better basis for feedback to Finnish hospitals than overall SSI rates

Retrospective cohort study

Hospitals conducting surveillance of hip arthroplasties (HPROs) and knee arthroplasties (KPROs) in the Finnish Hospital Infection Program

We analyzed surveillance data for 73,227 HPROs and 56,860 KPROs performed in 18 hospitals during 1999–2014. For each hospital, the overall, deep, and adjusted deep SSI rates with 95% confidence intervals (CIs) were calculated, and the hospital ranks were simulated in the Bayesian framework. Adjustments were performed using relevant patient and hospital characteristics. The correlation between the median expected hospital ranks in overall versus deep SSI rates and deep vs adjusted deep SSI rates were assessed using Spearman’s correlation coefficient ρ.

For HPRO, the overall SSI rates ranged from 0.92 to 6.83, the deep SSI rates ranged from 0.34 to 1.86, and the adjusted deep hospital-specific SSI rates ranged from 0.37 to 1.85. For KPRO, the overall SSI rates ranged from 0.71 to 5.03, the deep SSI rates ranged from 0.42 to 1.60, and the adjusted deep hospital-specific SSI rates ranged from 0.56 to 1.55. For both procedures, the 95% CIs of the rates between hospitals largely overlapped; only single outliers were detected. Hospital rank did not correlate between overall and deep SSI rates (HPRO, ρ=0.03; KPRO, ρ=0.40), but a correlation was observed in hospital rank for deep and adjusted deep SSI rates (HPRO, ρ=0.85; KPRO, ρ=0.94).

Deep SSI rates may be a better tool for interhospital comparisons than overall SSI rates. Although the adjustment could lead to fairer hospital ranking, it is not always necessary for feedback.

Infect Control Hosp Epidemiol 2017;38:423–429

To create an affordable and accurate method for continuously monitoring bacterial transmission rates in healthcare settings.

We present a discrete simulation model that relies on the relationship between in-hospital transmission rates and strain diversity. We also present a proof of concept application of this model to a prospective molecular epidemiology data set to estimate transmission rates for Pseudomonas aeruginosa and Staphylococcus aureus.

Inpatient units of an academic referral center.

All inpatients with nosocomial infections.

Mathematical model to estimate transmission rates.

Maximum likelihood estimates for transmission rates of these two species on different hospital units ranged from 0 to 0.36 transmission event per colonized patient per day.

This approach is feasible, although estimates of transmission rates based solely on strain typed clinical cultures may be too imprecise for routine use in infection control. A modest level of surveillance sampling substantially improves the estimation accuracy. (Infect Control Hosp Epidemiol 2005;26:638-645)

The incidence of surgical site infections may be underreported if the data are not routinely validated for accuracy. Our goal was to investigate the communicated SSI rate from a large network of Swiss hospitals compared with the results from on-site surveillance quality audits.

Retrospective cohort study.

In total, 81,957 knee and hip prosthetic arthroplasties from 125 hospitals and 33,315 colorectal surgeries from 110 hospitals were included in the study.

Hospitals had at least 2 external audits to assess the surveillance quality. The 50-point standardized score per audit summarizes quantitative and qualitative information from both structured interviews and a random selection of patient records. We calculated the mean National Healthcare Safety Network (NHSN) risk index adjusted infection rates in both surgery groups.

The median NHSN adjusted infection rate per hospital was 1.0% (interquartile range [IQR], 0.6%–1.5%) with median audit score of 37 (IQR, 33–42) for knee and hip arthroplasty, and 12.7% (IQR, 9.0%–16.6%), with median audit score 38 (IQR, 35–42) for colorectal surgeries. We observed a wide range of SSI rates and surveillance quality, with discernible clustering for public and private hospitals, and both lower infection rates and audit scores for private hospitals. Infection rates increased with audit scores for knee and hip arthroplasty (P value for the slope = .002), and this was also the case for planned (P = .002), and unplanned (P = .02) colorectal surgeries.

Surveillance systems without routine evaluation of validity may underestimate the true incidence of SSIs. Audit quality should be taken into account when interpreting SSI rates, perhaps by adjusting infection rates for those hospitals with lower audit scores.

Few data are available to quantify the Clostridioides difficile infection (CDI) burden in US adults depending on Medicaid insurance status; thus, we sought to contribute to this body of information.

Retrospective cohort study to identify adults with codes for CDI from 2011 to 2017 in MarketScan commercial and Medicaid databases (for those aged 25–64 years) and the CMS Medicare database (for those aged ≥65 years). CDI was categorized as healthcare-facility–associated (HCA-CDI) and community-associated CDI (CA-CDI). CDI incidence rates were compared by year, insurer, and age group.

The overall CDI incidence in the elderly was 3.1-fold higher in persons insured by Medicare plus Medicaid than in those insured by Medicare only (1,935 vs 618 per 100,000 person years (PY)), and the CDI incidence was 2.7-fold higher in younger adults with Medicaid compared to commercial insurance (195 vs 73 per 100,000 PY). From 2011 to 2017, HCA-CDI rates declined in the younger Medicaid population (124.0 to 95.2 per 100,000 PY; P < .001) but were stable in those commercially insured (25.9 to 24.8 per 100,000 PY; P = .33). In the elderly HCA-CDI rates declined from 2011 to 2017 in the Medicare-only population (403 to 318 per 100,000 PY; P < .001) and the Medicare plus Medicaid population (1,770 to 1,163 per 100,000 PY; P < .002). Persons with chronic medical conditions and those with immunocompromising conditions insured by Medicaid had 2.8- and 2.7-fold higher CDI incidence compared to the commercially insured population, respectively. The incidence of CDI was lowest in Medicaid and commercially insured younger adults without chronic medical or immunosuppressive conditions (67.5 and 45.6 per 100,000 PY, respectively).

Although HCA-CDI incidence decreased from 2011 to 2017 in elderly and younger adults insured by Medicaid, the burden of CDI remains much higher in low-income adults insured by Medicaid.

To determine the longitudinal changes in viral load of hepatitis B virus (HBV)–infected healthcare workers (HCWs) and its consequences for exclusion of infected HCWs performing exposure-prone procedures, various HBV DNA safety thresholds, and the frequency of monitoring.

Retrospective cohort study June 1, 1996–January 31, 2013.

In the Netherlands, chronically HBV-infected HCWs performing exposure-prone procedures are notified to the Committee for Prevention of Iatrogenic Hepatitis B. Of the 126 notified HCWs, 45 had 2 or more HBV DNA levels determined without antiviral therapy.

A time-to-event analysis for HBV-infected HCWs categorized in various viremia levels surpassing a HBV DNA threshold level of 1×105 copies/mL, above which exposure-prone procedures are not allowed in the Netherlands.

Fluctuations of HBV DNA in follow-up samples ranged from −5.4 to +2.2 log10 copies/mL. A high correlation was seen for each HBV DNA level with the 3 previous levels. In a time-to-event analysis, after 6 months 7.2%, 6.5%, and 14.3% of individuals had surpassed the threshold of 1×105 copies/mL for viral load categories 4.8×103 to 1.5×104; 1.5×104 to 4.0×104; and 4.0×104 to 1.0×105, respectively.

We propose standard retesting every 6 months, with more frequent retesting just below the high threshold value (1×105 copies/mL), and prolonging this standard interval to 1 year after 3 consecutive levels below the threshold in policies with lower safety thresholds (1×103 or 1×104 copies/mL).

Infect Control Hosp Epidemiol 2016;37:655–660

Automated surveillance methods increasingly replace or support conventional (manual) surveillance; the latter is labor intensive and vulnerable to subjective interpretation. We sought to validate 2 previously developed semiautomated surveillance algorithms to identify deep surgical site infections (SSIs) in patients undergoing colorectal surgeries in Dutch hospitals.

Multicenter retrospective cohort study.

From 4 hospitals, we selected colorectal surgery patients between 2018 and 2019 based on procedure codes, and we extracted routine care data from electronic health records. Per hospital, a classification model and a regression model were applied independently to classify patients into low- or high probability of having developed deep SSI. High-probability patients need manual SSI confirmation; low-probability records are classified as no deep SSI. Sensitivity, positive predictive value (PPV), and workload reduction were calculated compared to conventional surveillance.

In total, 672 colorectal surgery patients were included, of whom 28 (4.1%) developed deep SSI. Both surveillance models achieved good performance. After adaptation to clinical practice, the classification model had 100% sensitivity and PPV ranged from 11.1% to 45.8% between hospitals. The regression model had 100% sensitivity and 9.0%–14.9% PPV. With both models, <25% of records needed review to confirm SSI. The regression model requires more complex data management skills, partly due to incomplete data.

In this independent external validation, both surveillance models performed well. The classification model is preferred above the regression model because of source-data availability and less complex data-management requirements. The next step is implementation in infection prevention practices and workflow processes.

To explore the frequency of hand hygiene opportunities (HHOs) in multiple units of an acute-care hospital.

Prospective observational study.

The adult intensive care unit (ICU), medical and surgical step-down units, medical and surgical units, and the postpartum mother–baby unit (MBU) of an academic acute-care hospital during May–August 2013, May–July 2014, and June–August 2015.

Healthcare workers (HCWs).

HHOs were recorded using direct observation in 1-hour intervals following Public Health Ontario guidelines. The frequency and distribution of HHOs per patient hour were determined for each unit according to time of day, indication, and profession.

In total, 3,422 HHOs were identified during 586 hours of observation. The mean numbers of HHOs per patient hour in the ICU were similar to those in the medical and surgical step-down units during the day and night, which were higher than the rates observed in medical and surgical units and the MBU. The rate of HHOs during the night significantly decreased compared with day (P<.0001). HHOs before an aseptic procedure comprised 13% of HHOs in the ICU compared with 4%–9% in other units. Nurses contributed >92% of HHOs on medical and surgical units, compared to 67% of HHOs on the MBU.

Assessment of hand hygiene compliance using product utilization data requires knowledge of the appropriate opportunities for hand hygiene. We have provided a detailed characterization of these estimates across a wide range of inpatient settings as well as an examination of temporal variations in HHOs.

Infect Control Hosp Epidemiol 2017;38:411–416