Costs and resource utilization patterns in surgical site infections: a pre-COVID-19 perspective from France, Germany, Spain, and the UK.

BACKGROUND: Surgical site infections (SSIs), mainly caused by Staphylococcus aureus, pose a significant economic burden in Europe, leading to increased hospitalization duration, mortality, and treatment costs, particularly with drug-resistant strains such as meticillin-resistant S. aureus. AIM: To conduct a case-control study on the economic impact of S. aureus SSI in adult surgical patients across high-volume centres in France, Germany, Spain, and the UK, aiming to assess the overall and procedure-specific burden across Europe. METHODS: The SALT study is a multinational, retrospective cohort study with a nested case-control analysis focused on S. aureus SSI in Europe. The study included participants from France, Germany, Italy, Spain, and the UK who underwent invasive surgery in 2016 and employed a micro-costing approach to evaluate health economic factors, matching S. aureus SSI cases with controls. FINDINGS: In 2016, among 178,904 surgical patients in five European countries, 764 developed S. aureus SSI. Matching 744 cases to controls, the study revealed that S. aureus SSI cases incurred higher immediate hospitalization costs (€8,810), compared to controls (€6,032). Additionally, S. aureus SSI cases exhibited increased costs for readmissions within the first year post surgery (€7,961.6 versus €5,298.6), with significant differences observed. Factors associated with increased surgery-related costs included the cost of hospitalization immediately after surgery, first intensive care unit (ICU) admission within 12 months, and hospital readmission within 12 months, as identified through multivariable analysis. CONCLUSION: The higher rates of hospitalization, ICU admissions, and readmissions among S. aureus SSI cases highlight the severity of these infections and their impact on healthcare costs, emphasizing the potential benefits of evidence-based infection control measures and improved patient care to mitigate the economic burden.

Trends of the Use of Anti-methicillin-Resistant Staphylococcus aureus Agents in Japan Based on Sales Data from 2006 to 2015.

Patterns of the use of anti-methicillin-resistant Staphylococcus aureus (MRSA) agents in Japan might be influenced by the launch of new anti-MRSA agents, the publication of relevant guidelines, and the increase in the number of generic medicines. However, as anti-MRSA agents are included in multiple anatomical therapeutic chemical classifications, such as glycopeptides and aminoglycosides, the trends of the use of individual anti-MRSA agents remain unclear. Here, we aimed to clarify the trends of anti-MRSA agent use in Japan from 2006 to 2015 based on sales data. Total anti-MRSA agent use was found to have significantly increased from 2006 to 2015 (Pfor trend = 0.027, r = 0.00022). Individual trends for vancomycin (VCM), daptomycin, and linezolid (LZD) use showed significant increases, while those for arbekacin (ABK) and teicoplanin (TEIC) showed decreases. In addition, oral LZD use significantly increased, while there was no significant change in intravenous LZD use. The ratio of oral LZD use to total LZD use increased from 25.5% in 2006 to 39.9% in 2015. Meanwhile, TEIC and ABK use decreased, while VCM use increased, following the launch of generic medicines. These results might reflect the status of guideline compliance, the launch of new anti-MRSA agents, and the decline in the sales promotion of the original medicines. It is extremely important to investigate trends for the use of not only different antibiotic groups but also individual antibiotics to develop and implement antimicrobial resistance countermeasures.

Device associated -health care associated infections monitoring, prevention and cost assessment at intensive care unit of University Hospital in Poland (2015-2017).

BACKGROUND: Device-associated health care-associated infections (DA-HAIs) in intensive care unit (ICU) patients constitute a major therapeutic issue complicating the regular hospitalisation process and having influence on patients' condition, length of hospitalisation, mortality and therapy cost. METHODS: The study involved all patients treated > 48 h at ICU of the Medical University Teaching Hospital (Poland) from 1.01.2015 to 31.12.2017. The study showed the surveillance and prevention of DA-HAIs on International Nosocomial Infection Control Consortium (INICC) Surveillance Online System (ISOS) 3 online platform according to methodology of the INICC multidimensional approach (IMA). RESULTS: During study period 252 HAIs were found in 1353 (549F/804M) patients and 14,700 patient-days of hospitalisation. The crude infections rate and incidence density of DA-HAIs was 18.69% and 17.49 ± 2.56 /1000 patient-days. Incidence density of ventilator-associated pneumonia (VAP), central line-associated bloodstream infection (CLA-BSI) and catheter-associated urinary tract infection (CA-UTI) per 1000 device-days were 12.63 ± 1.49, 1.83 ± 0.65 and 6.5 ± 1.2, respectively. VAP(137) constituted 54.4% of HAIs, whereas CA-UTI(91) 36%, CLA-BSI(24) 9.6%.The most common pathogens in VAP and CA-UTI was multidrug-resistant (MDR) Acinetobacter baumannii (57 and 31%), and methicillin-resistant Staphylococcus epidermidis (MRSE) in CLA-BSI (45%). MDR Gram negative bacteria (GNB) 159 were responsible for 63.09% of HAIs. The length of hospitalisation of patients with a single DA-HAI at ICU was 21(14-33) days, while without infections it was 6.0 (3-11) days; p = 0.0001. The mortality rates in the hospital-acquired infection group and no infection group were 26.1% vs 26.9%; p = 0.838; OR 0.9633;95% CI (0.6733-1.3782). Extra cost of therapy caused by one ICU acquired HAI was US$ 11,475/Euro 10,035. Hand hygiene standards compliance rate was 64.7%, while VAP, CLA-BSI bundles compliance ranges were 96.2-76.8 and 29-100, respectively. CONCLUSIONS: DA-HAIs was diagnosed at nearly 1/5 of patients. They were more frequent than in European Centre Disease Control report (except for CLA-BSI), more frequent than the USA CDC report, yet less frequent than in limited-resource countries (except for CA-UTI). They prolonged the hospitalisation period at ICU and generated substantial additional costs of treatment with no influence on mortality. The Acinetobacter baumannii MDR infections were the most problematic therapeutic issue. DA-HAIs preventive methods compliance rate needs improvement.

Increased financial burdens and lengths of stay in patients with healthcare-associated infections due to multidrug-resistant bacteria in intensive care units: A propensity-matched case-control study.

BACKGROUND AND OBJECTIVES: Incidence rates of healthcare-associated infections (HAIs) depend upon infection control policy and practices, and the effectiveness of the implementation of antibiotic stewardship. Amongst intensive care unit (ICU) patients with HAIs, a substantial number of pathogens were reported to be multidrug-resistant bacteria (MDRB). However, impacts of ICU HAIs due to MDRB (MDRB-HAIs) remain understudied. Our study aimed to evaluate the negative impacts of MRDB-HAIs versus HAIs due to non-MDRB (non-MRDB-HAIs). METHODS: Among 60,317 adult patients admitted at ICUs of a 2680-bed medical centre in Taiwan between January 2010 and December 2017, 279 pairs of propensity-score matched MRDB-HAI and non-MRDB-HAI were analyzed. PRINCIPAL FINDINGS: Between the MDRB-HAI group and the non-MDRB-HAI group, significant differences were found in overall hospital costs, costs of medical and nursing services, medication, and rooms/beds, and in ICU length-of-stay (LOS). As compared with the non-MDRB-HAI group, the mean of the overall hospital costs of patients in the MDRB-HAI group was increased by 26%; for categorized expenditures, the mean of costs of medical and nursing services of patients in the MDRB-HAI group was increased by 8%, of medication by 26.9%, of rooms/beds by 10.3%. The mean ICU LOS in the MDRB-HAI group was increased by 13%. Mortality rates in both groups did not significantly differ. CONCLUSIONS: These data clearly demonstrate more negative impacts of MDRB-HAIs in ICUs. The quantified financial burdens will be helpful for hospital/government policymakers in allocating resources to mitigate MDRB-HAIs in ICUs; in case of need for clarification/verification of the medico-economic burdens of MDRB-HAIs in different healthcare systems, this study provides a model to facilitate the evaluations.

Clinical and economic impact of methicillin-resistant Staphylococcus aureus: a multicentre study in China.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious threat to global health. In China, the proportion of S. aureus isolates that were MRSA was 44.6% in 2014. The clinical and economic impact of MRSA in China remains largely uninvestigated. This study aims to compare the differences in hospital costs, length of hospital stay, and hospital mortality rate between MRSA and methicillin-susceptible S. aureus (MSSA) colonization or infection and between MRSA cases and those without an S. aureus infection. A retrospective and multicentre study was conducted in four tertiary hospitals in China between 2013 and 2015. Inpatient characteristics and hospital costs were collected from electronic medical records. We conducted propensity score matching (PSM) to eliminate selection bias by balancing the potential confounding variables between the two groups. The main indicators included hospital costs, length of hospital stay, and hospital mortality rate. A total of 1,335 inpatients with MRSA, 1,397 with MSSA, and 33,606 without an S. aureus infection were included. PSM obtained 954 and 1,313 pairs between the MRSA and MSSA groups and between the MRSA and S. aureus-free groups, respectively. After PSM, MRSA colonization or infection is associated with an increased total hospital cost ranging from $3,220 to $9,606, an excess length of hospital stay of 6 days-14 days, and an attributable hospital mortality rate of 0-3.58%. Between the MRSA and MSSA groups, MRSA colonization or infection was significantly associated with a higher total hospital cost and longer length of hospital stay among survivors but not among non-survivors; however, there were no differences in the hospital mortality rate between these two groups. Between the MRSA and the S. aureus-free groups, MRSA colonization or infection was significantly associated with an increased total hospital cost, a prolonged length of hospital stay and a higher hospital mortality rate among both survivors and non-survivors. It is critical to quantify the clinical and economic impact of MRSA to justify resource allocation for the development of strategies to improve clinical outcomes and to reduce the economic burden.

Burden of Staphylococcus aureus infections after orthopedic surgery in Germany.

BACKGROUND: This study assessed incidence, risk factors, and outcomes of Staphylococcus aureus infections (SAI) following endoprosthetic hip or knee, or spine surgeries. METHODS: Adult patients with at least one of the selected surgeries from 2012 to 2015 captured in a German sickness fund database were included. SAI were identified using S. aureus-specific ICD-10 codes. Patients with certain prior surgeries and infections were excluded. Cumulative incidence and incidence density of post-surgical SAI were assessed. Risk factors, mortality, healthcare resource utilization and direct costs were compared between SAI and non-SAI groups using multivariable analyses over the 1 year follow-up. RESULTS: Overall, 74,327 patients who underwent a knee (28.6%), hip (39.6%), or spine surgery (31.8%) were included. The majority were female (61.58%), with a mean age of 69.59 years and a mean Charlson Comorbidity Index (CCI) of 2.3. Overall, 1.92% of observed patients (20.20 SAI per 1000 person-years (PY)) experienced a SAI within 1 year of index hospitalization. Knee surgeries were associated with lower SAI risk compared with hip surgeries (Hazard Ratio (HR) = 0.8; p = 0.024), whereas spine surgeries did not differ significantly from hip surgeries. Compared with non-SAI group, the SAI group had on average 4.4 times the number of hospitalizations (3.1 vs. 0.7) and 7.7 times the number of hospital days (53.5 vs. 6.9) excluding the index hospitalization (p < 0.001). One year post-orthopedic mortality was 22.38% in the SAI and 5.31% in the non-SAI group (p < 0.001). The total medical costs were significantly higher in the SAI group compared to non-SAI group (42,834€ vs. 13,781€; p < 0.001). Adjusting for confounders, the SAI group had nearly 2 times the all-cause direct healthcare costs (exp(b) = 1.9; p < 0.001); and 1.72 times higher risk of death (HR = 1.72; p < 0.001). CONCLUSIONS: SAI risk after orthopedic surgeries persists and is associated with significant economic burden and risk of mortality. Hence, risk reduction and prevention methods are of utmost importance.

Costs and Benefits of Alternative Strategies to Control the Spread of Livestock-Acquired Methicillin-Resistant Staphylococcus Aureus From Pig Production.

BACKGROUND: Livestock-acquired methicillin-resistant Staphylococcus aureus (LA-MRSA) is a concern in healthcare and a political priority in some countries. OBJECTIVE: This study investigates the net societal costs of 2 alternative strategies for controlling LA-MRSA in Denmark: (1) eradicating LA-MRSA in all pig housing units, and (2) containing LA-MRSA within the units. METHODS: Benefits and costs are considered for affected economic sectors: healthcare, pig production, pig-related industries, and public administration. RESULTS: The cost to society of eradication is estimated at €2.3 to €2.5 billion (present value). Containment will cost €55 to €93 million. For both strategies, the main cost lies in primary pig production-for containment this is mainly due to establishing and operating anterooms and shower rooms, and for eradication it is due to production losses, loss of genetic resources, and costs of cleaning and disinfection. CONCLUSION: Compared with these costs, health economic benefits are moderate for both strategies. Containment is superior to eradication when measured by a benefit-cost ratio.

Impact of infection control measures on the related costs and the amount of broad-spectrum antimicrobial agents used in a hospital: A time-series analysis.

Health care-associated infections (HAIs) worsen patient prognoses and increase medical costs. Antimicrobial stewardship (AMS), which involves appropriate use of antimicrobial agents and antiseptics, may be beneficial for addressing the issue of HAIs. In hospitals, an infection control team (ICT) plays an important role on the appropriate use of antimicrobial agents and antiseptics based on AMS. We aimed to conduct a time-series analysis of the efficacies of infection control measures in terms of related costs, amount of broad-spectrum antimicrobial agents used (carbapenems and quinolones), and methicillin-resistant Staphylococcus aureus (MRSA) detection rates. This retrospective cross-sectional study included in-hospital patients treated at a single institute between January 2012 and December 2015. The intervention start point (initiation of infection control measures) was January 2014. All survey items were subjected to segmented regression analysis using an autoregressive integrated moving average (ARIMA) model. Differences between pre-intervention and postintervention levels and their trends were assessed, using a statistical significance cutoff of P < .05. The infection control costs demonstrated a significantly increasing trend, despite significant decreases in the amount of carbapenems used. Accordingly, the implementation of infection control measures was associated with increased costs, whereas carbapenem use decreased immediately after intervention. Postintervention levels, trends of quinolone use, or MRSA detection rates did not reveal significant changes. Although implementation of infection control measures induced gradual increases in related costs, these measures led to immediate reductions in carbapenem use. Our study findings will support the establishment of more effective and economical infection control measures.

Core genome multi-locus sequence typing as an essential tool in a high-cost livestock-associated meticillin-resistant Staphylococcus aureus CC398 hospital outbreak.

BACKGROUND: Livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex (CC) 398 may be transmitted and cause morbidity and mortality in hospitals. The economic cost of stopping hospital transmission of LA-MRSA CC398 is poorly described. Early detection of transmission may limit the extent of the intervention. AIM: To evaluate core genome multi-locus sequence typing (cgMLST) for detecting transmission chains and to estimate the costs for interventions to prevent further spread after discovery of hospital transmission of LA-MRSA CC398. METHODS: Five patients were involved in two episodes of transmission of LA-MRSA CC398 in a hospital. Standard interventions including MRSA screening of patients and healthcare workers were initiated. Whole genome sequences of the five isolates and 17 epidemiologically unrelated MRSA CC398 isolates from other hospitalized patients were analysed by single nucleotide polymorphism (SNP) comparisons and cgMLST. The economic costs of constraining transmission were calculated from relevant sources. FINDINGS: The five isolates suspected to be involved in hospital transmission clustered with ≤2 SNPs in the draft genome sequences with some distance to other isolates. cgMLST allocated the five isolates to the same type, which was different from all but two of the sporadic isolates. Furthermore, cgMLST separated the five transmission isolates from all other isolates. The economic costs of the outbreak interventions exceeded €11,000 per patient. CONCLUSION: LA-MRSA CC398 is transmittable in hospitals, and intervention against transmission may reach considerable costs. cgMLST is useful in surveillance of hospital transmission of LA-MRSA.

Culture-Confirmed Staphylococcus aureus Infection after Elective Hysterectomy: Burden of Disease and Risk Factors.

Background: Our study sought to describe the incidence of culture-confirmed postsurgical Staphylococcus aureus infection after elective hysterectomy and evaluate patient characteristics, risk factors, and economic consequences associated with Staphylococcus aureus infection. Methods: This was a retrospective cohort study of patients in the United States (≥18 years old; Kaiser Permanente health plan members) who underwent elective hysterectomy from 2007 to 2013. Hysterectomies were categorized by surgical setting (inpatient vs. outpatient) and procedure (abdominal, laparoscopic, or vaginal). We estimated the cumulative incidence of culture-confirmed Staphylococcus aureus infection (90 days post-surgery) and compared healthcare resource utilization and costs (within 120 days post-surgery) among patients with/without Staphylococcus aureus infection or with other infection. Results: Among 30,960 patients identified, 20,675 underwent inpatient hysterectomy (abdominal: 47.8%; laparoscopic: 24.8%; vaginal: 27.3%), and 10,285 underwent outpatient hysterectomy (laparoscopic: 86.1%; vaginal: 13.9%). The incidence of culture-confirmed Staphylococcus aureus infection was 0.8% and 0.4% for inpatient (abdominal: 1.2%; laparoscopic: 0.5%; vaginal: 0.2%) and outpatient (laparoscopic: 0.5%; vaginal: 0.1%) surgery, respectively. Patients with Staphylococcus aureus infection had more emergency department visits, hospitalizations, and re-operations compared with patients without infection or with non-Staphylococcus aureus infection. Mean total costs for patients with Staphylococcus aureus infection were higher (inpatient: $18,261; outpatient: $4,422) compared with patients without infection (inpatient: $6,171; p < 0.0001; outpatient: $905; p = 0.0023) or non-Staphylococcus aureus infection (inpatient: $11,207; p = 0.0117; outpatient: $3,005; p = 0.2117). Conclusions: Culture-confirmed postsurgical Staphylococcus aureus infection incidence was predominately associated with procedure type rather than surgical setting. Patients with post-surgical Staphylococcus aureus infection had higher health care utilization and costs than those without infection or with other infection types. Additional effective infection control strategies are needed to reduce the morbidity and costs associated with Staphylococcus aureus infection.

Comparing methods to estimate incremental inpatient costs and length of stay due to methicillin-resistant Staphylococcus aureus in Alberta, Canada.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic bacterial organism resistant to first line antibiotics. Acquisition of MRSA is often classified as either healthcare-associated or community-acquired. It has been shown that both healthcare-associated and community-acquired infections contribute to the spread of MRSA within healthcare facilities. The objective of this study was to estimate the incremental inpatient cost and length of stay for individuals colonized or infected with MRSA. Common analytical methods were compared to ensure the quality of the estimate generated. This study was performed at Alberta Ministry of Health (Edmonton, Alberta), with access to clinical MRSA data collected at two Edmonton hospitals, and ministerial administrative data holdings. METHODS: A retrospective cohort study of patients with MRSA was identified using a provincial infection prevention and control database. A coarsened exact matching algorithm, and two regression models (semilogarithmic ordinary least squares model and log linked generalized linear model) were evaluated. A MRSA-free cohort from the same facilities and care units was identified for the matched method; all records were used for the regression models. Records span from January 1, 2011 to December 31, 2015, for individuals 18 or older at discharge. RESULTS: Of the models evaluated, the generalized linear model was found to perform the best. Based on this model, the incremental inpatient costs associated with hospital-acquired cases were the most costly at $31,686 (14,169 - 60,158) and $47,016 (23,125 - 86,332) for colonization and infection, respectively. Community-acquired MRSA cases also represent a significant burden, with incremental inpatient costs of $7397 (2924 - 13,180) and $14,847 (8445 - 23,207) for colonization and infection, respectively. All costs are adjusted to 2016 Canadian dollars. Incremental length of stay followed a similar pattern, where hospital-acquired infections had the longest incremental stays of 35.2 (16.3-69.5) days and community-acquired colonization had the shortest incremental stays of 3.0 (0.6-6.3) days. CONCLUSIONS: MRSA, and in particular, hospital-acquired MRSA, places a significant but preventable cost burden on the Alberta healthcare system. Estimates of cost and length of stay varied by the method of analysis and source of infection, highlighting the importance of selecting the most appropriate method.

A cost-effectiveness analysis of mupirocin and chlorhexidine gluconate for Staphylococcus aureus decolonization prior to hip and knee arthroplasty in Alberta, Canada compared to standard of care.

Background: While decolonization of Staphylococcus aureus reduces surgical site infection (SSI) rates following hip and knee arthroplasty, its cost-effectiveness is uncertain. We sought to examine the cost-effectiveness of a decolonization protocol for Staphylococcus aureus prior to hip and knee replacement in Alberta compared to standard care - no decolonization. Methods: Decision analytic models and a probabilistic sensitivity analysis were used for a cost-effectiveness analysis, with the effectiveness of decolonization based on a large published pre- and post- intervention trial. The primary outcomes of the models were infections prevented and health care costs. We modelled the cost-effectiveness of decolonization in a hypothetical cohort of adult patients undergoing hip and knee replacement in Alberta, Canada. Information on the incidence of complex surgical site infections (SSIs), as well as the cost of care for patients with and without SSIs was taken from a provincial infection control database, and health administrative data. Results: Use of the decolonization bundle was cost saving compared to usual care ($153/person), and resulted in 16 complex Staphylococcus aureus SSIs annually as opposed to 32 (with approximately 8000 hip or knee arthroplasties performed). The probabilistic sensitivity analysis demonstrated that the majority (84%) of the time the decolonization bundle was cost saving. The model was robust to one-way sensitivity analyses conducted within plausible ranges. There were small upfront costs associated with using a decolonization protocol, however, this model demonstrated cost savings over one year. In a Markov model that considered the impact of a decolonization bundle over a lifetime as it pertained to the need for subsequent joint replacements and patient quality of life, the bundle still resulted in cost savings ($161/person). Conclusions: Decolonization for Staphylococcus aureus prior to hip and knee replacements resulted in cost savings and fewer SSIs, and should be considered prior to these procedures.

Economic and epidemiological impact of different intervention strategies for subclinical and clinical mastitis.

The objective of this study was to evaluate and compare different combinations of intervention strategies for contagious or opportunistic subclinical and clinical intramammary infections (IMI). We simulated two different Danish dairy cattle herds with ten different intervention strategies focusing on cow-specific treatment or culling, including three baseline strategies without subclinical interventions. In one herd, the main causative pathogen of IMI was Staphylococcus (S.) aureus. In the other herd, Streptococcus (St.) agalactiae was the main causative agent. For both herds, we investigated costs and effectiveness of all ten intervention strategies. Intervention strategies consisted of measures against clinical and subclinical IMI, with baselines given by purely clinical intervention strategies. Our results showed that strategies including subclinical interventions were more cost-effective than the respective baseline strategies. Increase in income and reduction of IMI cases came at the cost of increased antibiotic usage and an increased culling rate in relation to IMI. However, there were differences between the herds. In the St. agalactiae herd, the clinical intervention strategy did not seem to have a big impact on income and number of cases. However, intervention strategies which included cow-specific clinical interventions led to a higher income and lower number of cases in the S. aureus herd. The results show that intervention strategies including interventions against contagious or opportunistic clinical and subclinical IMI can be highly cost-effective, but should be herd-specific.

Patterns of Health Care Costs Due to External Ventricular Drain Infections.

BACKGROUND: External ventricular drain (EVD) infections are a significant cause of morbidity among neurosurgical patients and have been correlated with increased length of hospital stay and longer requirements for intensive care. To date, no studies have examined the financial impact of EVD infections. METHODS: Patients who underwent EVD placement between December 2010 and January 2016 were included in the study. Clinical records were retrospectively reviewed and health care cost data were obtained from the hospital's finance department. Clinical information included patient demographics, details from the hospital course, and outcomes. Total costs, direct/indirect, and fixed/variable costs were analyzed for every patient. RESULTS: Over the 5-year study period, 246 EVDs were placed in 243 patients with an overall infection rate of 9.9% (N = 24). The median EVD duration for infected versus noninfected patients was 19 and 9 days, respectively (P < 0.0001). Median length of intensive care unit stay also was increased for patients with EVD infection (30 days vs. 13 days, P < 0.0001). Total health care costs were significantly greater for infected patients (US$ 168,692 vs. US$ 83,919, P < 0.0001). This trend was comparable for all other cost subtypes, including fixed-direct costs, fixed-indirect costs, variable direct costs, and variable-indirect costs. CONCLUSIONS: EVD infection has a substantial effect on clinical morbidity and healthcare costs. These results demonstrate the imperative need to improve EVD infection prevention, particularly in the setting of a value-based health care system.

Health state utilities associated with post-surgical Staphylococcus aureus infections.

INTRODUCTION: Surgical site infections (SSIs) are among the most common and potentially serious complications after surgery. Staphylococcus aureus is a virulent pathogen frequently identified as a cause of SSI. As vaccines and other infection control measures are developed to reduce SSI risk, cost-utility analyses (CUA) of these interventions are needed to inform resource allocation decisions. A recent systematic review found that available SSI utilities are of "questionable quality." Therefore, the purpose of this study was to estimate the disutility (i.e., utility decrease) associated with SSIs. METHODS: In time trade-off interviews, general population participants in the UK (London, Edinburgh) valued health states drafted based on literature and clinician interviews. Health states described either joint or spine surgery, with or without an SSI. The utility difference between otherwise identical health states with and without the SSI represented the disutility associated with the SSI. RESULTS: A total of 201 participants completed interviews (50.2% female; mean age = 46.2 years). Mean (SD) utilities of health states describing joint and spine surgery without infections were 0.79 (0.23) and 0.78 (0.23). Disutilities of SSIs ranged from - 0.03 to - 0.32, depending on severity of the infection and subsequent medical interventions. All differences between corresponding health with and without SSIs were statistically significant (all p < 0.001). CONCLUSION: The preference-based SSI disutilities derived in this study may be used to represent mild and serious SSIs in CUAs assessing and comparing the value of vaccinations that may reduce the risk of SSIs.

Would hemodialysis patients benefit from a Staphylococcus aureus vaccine?

Staphylococcus aureus bloodstream infection can have potentially catastrophic consequences for patients on hemodialysis. Consequently, an effective vaccine to prevent S aureus infection would have a significant influence on morbidity and mortality in this group. To date, however, efforts to develop a vaccine have been unsuccessful. Previous antibody-inducing vaccine candidates did not prevent or attenuate S aureus infection in clinical trials. Recent advances have helped to elucidate the role of specific T-cell subsets, notably T-helper cell 1 and T-helper cell 17, in the immune response to S aureus. These cells are essential for coordinating an effective phagocytic response via cytokine production, indirectly leading to destruction of the organism. It is now widely accepted that next-generation S aureus vaccines must also induce effective T-cell-mediated immunity. However, there remains a gap in our knowledge: how will an S aureus vaccine drive these responses in those patients most at risk? Given that patients on hemodialysis are an immunocompromised population, in particular with specific T-cell defects, including defects in T-helper cell subsets, this is likely to affect their ability to respond to an S aureus vaccine. We urgently need a better understanding of T-cell-mediated immunity in this cohort if an efficacious vaccine is ever to be realized for these patients.

Economic and epidemiological impact of different intervention strategies for clinical contagious mastitis.

The overall aim of this study was to compare different intervention strategies for clinical intramammary infections (IMI). We conducted a simulation study to represent a Danish dairy cattle herd with IMI caused mostly by Staphylococcus aureus and 9 different intervention strategies for clinical IMI. A standard intervention of 3 d of treatment consisting of intramammary injections for all clinical cases was used. Two of the strategies reflected the use of more antibiotics and 6 strategies reflected cow-specific treatment or culling decisions. For these strategies, we assessed the cost and effectiveness of culling as an IMI intervention. Our results showed that nearly all strategies could reduce the number of IMI cases [e.g., a median of 37 clinical cases with the extended intramammary treatment over 5 d strategy (Basic5) and 30 clinical cases with the cow culled with recovery probability below 50% (Before50)] compared with the standard intervention (median of 42 clinical cases). This happened alongside either increased antibiotic usage (e.g., from a median of 123 treatment days up to 179 treatment days with strategy Basic5) or an increased number of cows culled in relation to IMI (e.g., from a median of 16 up to 24 cows with strategy Before50). Strategies with more antibiotics or reactive culling had a slightly higher net income (e.g., €190,014 median net income with strategy Basic5 or €196,995 with strategy Before50 compared with €187,666 with the standard strategy). This shows that a cow-specific clinical intervention approach can be cost-effective in reducing IMI incidence.

National Costs Associated With Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus Hospitalizations in the United States, 2010-2014.

Background: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have been associated with worse patient outcomes and higher costs of care than methicillin-susceptible (MSSA) infections. However, since prior studies found these differences, the healthcare landscape has changed, including widespread dissemination of community-associated strains of MRSA. We sought to provide updated estimates of the excess costs of MRSA infections. Methods: We conducted a retrospective analysis using data from the National Inpatient Sample from the Agency for Healthcare Research and Quality for the years 2010-2014. We calculated costs for hospitalizations, including MRSA- and MSSA-related septicemia and pneumonia infections, as well as MRSA- and MSSA-related infections from conditions classified elsewhere and of an unspecified site ("other infections"). Differences in the costs of hospitalization were estimated using propensity score-adjusted mortality outcomes for 2010-2014. Results: In 2014, estimated costs were highest for pneumonia and sepsis-related hospitalizations. Propensity score-adjusted costs were significantly higher for MSSA-related pneumonia ($40725 vs $38561; P = .045) and other hospitalizations ($15578 vs $14792; P < .001) than for MRSA-related hospitalizations. Similar patterns were observed from 2010 to 2013, although crude cost differences between MSSA- and MRSA-related pneumonia hospitalizations rose from 25.8% in 2010 to 31.0% in 2014. Compared with MSSA-related hospitalizations, MRSA-related hospitalizations had a higher adjusted mortality rate. Conclusions: Although MRSA infections had been previously associated with higher hospitalization costs, our results suggest that, in recent years, costs associated with MSSA-related infections have converged with and may surpass costs of similar MRSA-related hospitalizations.

Reevaluation of the impact of methicillin-resistance on outcomes in patients with Staphylococcus aureus bacteremia and endocarditis.

BACKGROUND/AIMS: Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent in hospitals, and has recently emerged in the community. The impact of methicillin-resistance on mortality and medical costs for patients with S. aureus bacteremia (SAB) requires reevaluation. METHODS: We searched studies with SAB or endocarditis using electronic databases including Ovid-Medline, Embase-Medline, and Cochrane Library, as well as five local databases for published studies during the period January 2000 to September 2011. RESULTS: A total of 2,841 studies were identified, 62 of which involved 17,563 adult subjects and were selected as eligible. A significant increase in overall mortality associated with MRSA, compared to that with methicillin-susceptible S. aureus (MSSA), was evidenced by an odds ratio (OR) of 1.95 (95% confidence interval [CI], 1.73 to 2.21; p < 0.01). In 13 endocarditis studies, MRSA increased the risk of mortality, with an OR of 2.65 (95% CI, 1.46 to 4.80). When three studies, which compared mortality rates between CA-MRSA and CA-MSSA, were combined, the risk of methicillin-resistance increased 3.23-fold compared to MSSA (95% CI, 1.25 to 8.34). The length of hospital stay in the MRSA group was 10 days longer than that in the MSSA group (95% CI, 3.36 to 16.70). Of six studies that reported medical costs, two were included in the analysis, which estimated medical costs to be $9,954.58 (95% CI, 8,951.99 to 10,957.17). CONCLUSION: MRSA is still associated with increased mortality, longer hospital stays and medical costs, compared with MSSA in SAB in studies published since the year 2000.

Cost and Hospital Resource Utilization of Staphylococcus aureus Infection Post Elective Posterior Instrumented Spinal Fusion Surgeries in U.S. Hospitals: A Retrospective Cohort Study.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The aim of this study was to assess hospital resource utilization and costs associated with Staphylococcus aureus infection within 180 days post elective posterior instrumented spinal fusion surgeries (index surgery) between 2010 and 2015. SUMMARY OF BACKGROUND DATA: Surgical site infections (SSIs) and blood stream infections (BSIs) post spinal fusion surgeries are associated with worse clinical outcomes and increased costs. Economic data specific to the most common pathogen of infections post spinal fusion surgeries, S. aureus, are limited. METHODS: We analyzed hospital discharge and microbiology data from 129 U.S. hospitals in Premier Healthcare Database. Selection criteria included age ≥ 18 years; had a primary/secondary ICD-9-CM procedure code for index surgery; and had microbiology data during study period. Outcomes included total hospitalization cost, length of stay, and risk of all-cause readmission. Infection status was classified as culture-confirmed invasive (i.e., BSIs, deep or organ/space SSIs), any, and no S. aureus infection. Multivariable regression analyses were used to compare outcome variables between infection groups controlling for known confounders. RESULTS: Two hundred ninety-four patients had any S. aureus infection (151 had invasive infection) and 12,918 had no infection. Compared with no infection group, invasive and any infection groups had higher total hospitalization cost (adjusted mean in 2015 U.S. dollars: $88,353 and $64,356 vs. $47,366, P < 0.001), longer length of stay (adjusted mean: 20.98 and 13.15 vs. 6.77 days, P < 0.001), and higher risk of all-cause readmission [adjusted risk ratio: 2.15 (95% confidence interval: 2.06-2.25) for invasive and 1.70 (95% confidence interval: 1.61-1.80) for any infection groups]. CONCLUSION: S. aureus infections post elective posterior instrumented spinal fusion surgeries are associated with significantly higher hospitalization cost, length of stay, and 180-day risk of readmission than those with no such infection, which presents substantial burden to hospitals and patients. Reducing such infections may cut costs and hospital resource utilization. LEVEL OF EVIDENCE: 3.