Direct medical costs associated with using vancomycin in methicillin-resistant Staphylococcus aureus infections: an economic model

Preparation Times and Estimated Costs for Vancomycin Formulations: Does the Difference Matter?

Objective Infections from methicillin-resistant Staphylococcus aureus are increasingly treated in longterm care facilities, but long-term care pharmacies face high costs in the provision of sterile vancomycin for intravenous administration. This study compares pharmaceutical costs of outsourced, compounded, and room temperature premixed vancomycin formulations in a long-term care pharmacy. Design This retrospective observational study reviewed 124 orders of vancomycin. Means for total pharmacy preparation time, pharmacist labor time, and extrapolated time over complete course of treatment were compared for three vancomycin preparations: outsourced, compounded by pharmacy, and room temperature premixed vancomycin formulations. Cost calculations were generated using ingredient costs as reported by the pharmacy and median pharmacist labor costs as published from national sources. Results Mean total preparation times and pharmacist preparation times were shortest for premixed vancomycin. Over full courses of treatment, mean pharmacy preparation time for compounded was 5 hours 3 minutes (mean of 28 treatments) and 2 hours 8 minutes for premixed (mean of 54 treatments). Data on pharmacist time in outsourced orders were not available. Total pharmacy costs were $993.94 for compounded vancomycin, $2220.34 for outsourced, and $809.36 for room temperature premixed vancomycin. Conclusion There were reduced preparation times for room temperature premixed vancomycin compared with compounded and outsourced formulations for skilled nursing facilities. As multiple drug-resistant organism infections are increasingly treated in long-term care, finding cost-effective approaches to medication provision from pharmacies is critical.

The Potential Utility of Single-Dose Long-Acting Intravenous Antibiotics for Acute Bacterial Skin and Skin-Structure Infections in the Emergency Department

Acute bacterial skin and skin-structure infections (ABSSSIs) are frequent clinical presentations to emergency departments (EDs) across the nation that can require substantial resources to treat due to several factors. These include an increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) as the causative organism, limited availability of oral antibiotics that treat ABSSSIs secondary to MRSA, absorption and pharmacodynamic concerns with oral therapy, and regimen adherence. In patients who are unable to tolerate oral therapy, or are unable to adhere to prescribed antibiotics, inpatient admission for intravenous (IV) antibiotics may be necessary. Although inpatient IV antibiotics used to treat MRSA, such as vancomycin, are relatively inexpensive, hospital admission itself incurs significant associated costs. The introduction of the long-acting lipoglycopeptides, dalbavancin and oritavancin, has many potential advantages for the treatment of ABSSSIs including one- or two-dose regimens, allowing patients to receive their dose in the ED or infusion center and avoid inpatient admission altogether. Existing data have borne out these results, demonstrating that these agents can significantly reduce the length of hospital stay and the overall treatment cost of ABSSSIs. However, as these agents have nontraditional therapeutic regimens compared with alternative IV and oral agents that require consistent dosing, it is imperative to have decision support tools in place to ensure that this therapy is utilized in appropriate patients with ABSSSIs and that its true benefits can be realized for both the patient and the health care system.

Does prophylactic local tobramycin injection lower open fracture infection rates?

Objective: To determine whether local aqueous tobramycin injection in combination with systemic perioperative IV antibiotic prophylaxis will reduce the rate of fracture-related infection (FRI) after open fracture fixation. Other Outcomes of Interest: (1) To compare fracture nonunion rates and report differences between treatment and control groups and (2) compare bacterial speciation and antibiotic sensitivity among groups that develop FRI. Design: Phase 3 prospective, randomized clinical trial. Setting: Two level 1 trauma centers. Participants: Six hundred subjects (300 in study/tobramycin group and 300 in control/standard practice group) will be enrolled and assigned to the study group or control group using a randomization table. Patients with open extremity fractures that receive definitive internal surgical fixation will be considered. Intervention: Aqueous local tobramycin will be injected into the wound cavity (down to bone) after debridement, irrigation, and fixation, following closure. Main Outcome Measurements: Outcomes will look at the presence or absence of FRI, the rate of fracture nonunion, and determine speciation of gram-negative and Staph bacteria in each group with a FRI. Results: Not applicable. Conclusion: The proposed work will determine whether local tobramycin delivery plus perioperative standard antibiotic synergism will minimize the occurrence of open extremity FRI. Level of Evidence: Level 1.

Vancomycin or Daptomycin for Outpatient Parenteral Antibiotic Therapy: Does It Make a Difference in Patient Satisfaction?

A 5-question telephone survey was administered to compare satisfaction between patients receiving vancomycin vs daptomycin outpatient parenteral antimicrobial therapy (OPAT). Twenty-seven patients completed the survey (40%). Vancomycin had higher daily interference score than daptomycin (P = .03). All patients receiving daptomycin reported a satisfaction score ≥8/10, as compared to 67% of patients who received vancomycin (P < .03). OPAT antibiotics with less cumbersome administration regimens may translate into higher patient satisfaction and quicker return to life normalcy.

Review of health economic models exploring and evaluating treatment and management of hospital-acquired pneumonia and ventilator-associated pneumonia

BACKGROUND

Hospital-acquired pneumonia (HAP) is pneumonia that occurs ≥48 h after hospital admission; it is the most common hospital-acquired infection contributing to death. Ventilator-associated pneumonia (VAP) arises ≥48-72 h after intubation. Opinions differ on whether VAP is a subset of HAP; the same pathogens predominate in both. Compared with VAP-free controls, patients developing VAP are twice as likely to die and have significantly longer stays in intensive care units. Guidelines recommend that microbiological cultures should guide antibiotic treatment, but these lack sensitivity and take 48-72 h to process, meaning that initial therapy must be empiric, generally with broad-spectrum agents. Given increasing pressure to improve both antibiotic stewardship and patient outcomes, the National Institute for Health and Care Excellence and the Infectious Diseases Society of America recommend research into rapid molecular diagnostic tests to identify causative organisms and their antibiotic resistances. Ideally, these would supersede culture, being quicker and more sensitive. In the UK, the INHALE research programme, funded by the National Institute for Health Research, is exploring rapid molecular diagnostics to inform treatment of HAP/VAP and, given resource implications, incorporates a health economic component.

AIM

To identify previous economic modelling of HAP/VAP costs to inform this component.

METHODS

Literature review of HAP/VAP studies with economic modelling identified from three databases.

FINDINGS

Twenty studies were identified. Only one study specifically evaluated strategies to improve diagnosis; the remaining 19 studies omitted this important aspect.

CONCLUSION

HAP/VAP modelling would be improved by better awareness of long-term outcomes and treatment complexity. To the authors' knowledge, no similar literature reviews of economic modelling for HAP/VAP have been published.

Modeling operational quality metrics and costs of long-acting antibiotics for acute bacterial skin and skin structure infection treatment in the emergency department

Aims: To model implementation of a new treatment pathway leveraging long-acting antibiotics (LAs) for treatment of acute bacterial skin and skin structure infections (ABSSSIs) in a hospital emergency department (ED) with an observation unit, and to quantify health resource utilization and economic outcomes versus standard care (intravenous vancomycin). Materials and methods: Discrete-event simulation was used to model implementation of the LA treatment pathway in the ED versus standard care from the US Medicare perspective. Model inputs were derived from published sources to simulate a real-world hospital ED with an observation unit. Outcomes included key ED metrics such as patient throughput rate and length of stay (LOS) and cost (estimated through reimbursed amounts in 2017 USD). Results: Implementation of an LA pathway in the ED improved ABSSSI patient throughput rate by 350% (+5.8 dispositions/ED and observation unit day) and reduced LOS by 68% (-7.2 h/patient). These improvements in patient outcomes are driven by the reduced infusion time required for LA antibiotics and are greater for dalbavancin than oritavancin owing to the shorter infusion duration (30 min vs. 3 h). Limitations: External validity of the model was not assessed. The model was limited to care received in EDs; therefore, certain clinical variables outside the ED were not captured for this analysis. Conclusions: LA pathway implementation for ABSSSI treatment in the ED supported improved efficiency, which may translate to economic value. As EDs continue to focus on improving key metrics such as throughput rate and LOS, LA pathway implementation should be considered as a potential approach for abbreviated ABSSSI treatment in the ED.

Modeling economic implications of alternative treatment strategies for acute bacterial skin and skin structure infections

OBJECTIVE

The economic implications from the US Medicare perspective of adopting alternative treatment strategies for acute bacterial skin and skin structure infections (ABSSSIs) are substantial. The objective of this study is to describe a modeling framework that explores the impact of decisions related to both the location of care and switching to different antibiotics at discharge.

METHODS

A discrete event simulation (DES) was developed to model the treatment pathway of each patient through various locations (emergency department [ED], inpatient, and outpatient) and the treatments prescribed (empiric antibiotic, switching to a different antibiotic at discharge, or a second antibiotic). Costs are reported in 2012 USD.

RESULTS

The mean number of days on antibiotic in a cohort assigned to a full course of vancomycin was 11.2 days, with 64% of the treatment course being administered in the outpatient setting. Mean total costs per patient were $8671, with inpatient care accounting for 58% of the costs accrued. The majority of outpatient costs were associated with parenteral administration rather than drug acquisition or monitoring. Scenarios modifying the treatment pathway to increase the proportion of patients receiving the first dose in the ED, and then managing them in the outpatient setting or prescribing an oral antibiotic at discharge to avoid the cost associated with administering parenteral therapy, therefore have a major impact and lower the typical cost per patient by 11-20%. Since vancomycin is commonly used as empiric therapy in clinical practice, based on these analyses, a shift in treatment practice could result in substantial savings from the Medicare perspective.

CONCLUSIONS

The choice of antibiotic and location of care influence the costs and resource use associated with the management of ABSSSIs. The DES framework presented here can provide insight into the potential economic implications of decisions that modify the treatment pathway.

Medicare home infusion therapy reimbursement gap

This research seeks to address the home infusion therapy reimbursement gap found within Medicare Part D. In particular, the research explored the reimbursement gap's impact on home health utilization, its contribution to the national health expenditure growth, and the potential fix of the problem by restructuring Medicare Part B to include a home infusion therapy benefit under its coverage. Previous studies found that there is a great cost avoidance opportunity available through home health and home infusion treatment, because such treatment avoids the high costs associated with hospitalization and nursing home and other long-term care facilities. Future implications of this topic are unclear, as the Affordable Health Care for America Act is equipped to cut Medicare services and reimbursements, in spite of current bipartisan legislation in both houses to cover the home infusion reimbursement gap.

Economic burden of inpatient and outpatient antibiotic treatment for methicillin-resistant Staphylococcus aureus complicated skin and soft-tissue infections: a comparison of linezolid, vancomycin, and daptomycin

Background

Previous economic analyses evaluating treatment of methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft-tissue infections (cSSTI) failed to include all direct treatment costs such as outpatient parenteral antibiotic therapy (OPAT). Our objective was to develop an economic model from a US payer perspective that includes all direct inpatient and outpatient costs incurred by patients with MRSA cSSTI receiving linezolid, vancomycin, or daptomycin.

Methods

A 4-week decision model was developed for this economic analysis. Published literature and database analyses with validation by experts provided clinical, resource use, and cost inputs on data such as efficacy rate, length of stay, adverse events, and OPAT services. Base-case analysis assumed equal efficacy and equal length of stay for treatments. We conducted several sensitivity analyses where assumptions on resource use or efficacy were varied. Costs were reported in year-end 2011 US dollars.

Results

Total treatment costs in the base-case were lower for linezolid ($10,571) than vancomycin ($11,096), and daptomycin ($13,612). Inpatient treatment costs were $740 more, but outpatient costs, $1,266 less with linezolid than vancomycin therapy due to a switch to oral linezolid when the patient was discharged. Compared with daptomycin, both inpatient and outpatient treatment costs were lower with linezolid by $87 and $2,954 respectively. In sensitivity analyses, linezolid had lower costs compared with vancomycin and daptomycin when using differential length of stay data from a clinical trial, and using success rates from a meta-analysis. In a scenario without peripherally inserted central catheter line costs, linezolid became slightly more expensive than vancomycin (by $285), but remained less costly than daptomycin (by $2,316).

Conclusion

Outpatient costs of managing MRSA cSSTI may be reduced by 30%–50% with oral linezolid compared with vancomycin or daptomycin. Results from this analysis support potential economic benefit and cost savings of using linezolid versus traditional OPAT when total inpatient and outpatient medical costs are evaluated.

Optimizing delivery of care for patients with MRSA infection: focus on transitions of care

Staphylococcus aureus is among the most prevalent pathogens isolated from hospitalized patients; those infected with methicillin-resistant strains have longer hospital stays and higher total costs compared with those infected by methicillin-susceptible strains. A multidisciplinary team of health care providers, including hospitalists and other hospital-based physicians, clinical pharmacists, infectious disease specialists, infection control professionals, and case managers, is key to improving treatment and outcomes in these patients. Optimizing transitions of care for hospitalized patients with S aureus infections can improve quality and reduce total costs of care. Hospital length of stay can be shortened by initiating timely, appropriate empiric therapy and by transitioning suitable patients to outpatient antimicrobial therapy. The number of hospitalizations can be reduced by identifying patients who are suitable candidates for initial outpatient antimicrobial therapy. Consistent with good antimicrobial stewardship, the risk of resistance can be minimized by de-escalating empiric therapy to a more narrow-spectrum agent once culture and susceptibility testing results are known. There are several antimicrobial agents available for the management of S aureus infections, including methicillin-resistant S aureus. Consideration of these agents' characteristics may facilitate optimal transition of patients through health care settings.

Efficacy and safety of linezolid in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft tissue infection (cSSTI): a meta-analysis

OBJECTIVE

To evaluate the clinical and microbiological outcomes of linezolid versus vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) complicated skin and soft-tissue infection (cSSTI) using a meta-analysis.

RESEARCH DESIGN AND METHODS

Clinical trials were identified using PubMed, the Cochrane Central Register of Controlled Trials, and the International Pharmaceutical Abstracts from inception to March 2009. Primary outcomes evaluated resolution of signs and symptoms of infection in clinically evaluable (CE) patients, and microbiological eradication in both the modified intent-to-treat (MITT) and MRSA evaluable (MRSA ME) patients. MITT patients had a culture-confirmed Gram-positive pathogen (S. aureus) at baseline. Secondary outcomes included mortality, adverse drug reactions (ADR), and discontinuation due to ADRs. The Mantel-Haenszel odds ratios (OR) with 95% confidence intervals (CI) were calculated using the fixed effects model based on the assumption that there was little to no heterogeneity between the studies in the primary analysis. Sensitivity analyses were performed for each outcome by removing the most weighted study.

RESULTS

Five studies with a total of 2652 patients (1361/linezolid; 1291/vancomycin) were identified. Resolution of infection in CE patients (OR = 1.41; 95% CI: 1.03, 1.95) and MITT patients (OR = 1.91; 95% CI: 1.33, 2.76) favored the use of linezolid over vancomycin, but did not remain significant after sensitivity analyses (CE: OR = 1.29; 95% CI: 0.81, 2.05; MITT: OR = 1.73; 95% CI: 0.87, 3.41). Microbiological eradication in MRSA ME patients consistently favored the use of linezolid over vancomycin (OR = 2.90; 95% CI: 1.90, 4.41). No difference in mortality was observed between the two groups (OR = 1.17; 95% CI: 0.85, 1.62). Higher proportions of linezolid patients were found to have diarrhea (119/1361 vs. 52/1291), nausea (102/1361 vs. 46/1291) and thrombocytopenia (54/1121 vs. 8/1071), whereas a higher proportion of vancomycin patients were found to have renal insufficiency compared to linezolid (16/634 vs. 4/703). Inconsistent results were seen with the incidence of anemia and rash between the base-case (anemia: OR = 1.36; 95% CI: 0.90, 2.08; rash: OR = 0.26; 95% CI: 0.10, 0.68) and sensitivity analyses (anemia: OR = 2.33; 95% CI: 1.24, 4.37; rash: OR = 0.57; 95% CI: 0.12, 2.71). Discontinuation due to ADRs was not statistically different between linezolid and vancomycin (OR = 1.06; 95% CI: 0.75, 1.51).

CONCLUSION

Resolution of infection in CE and MITT patients were inconsistent; however, a sub-analysis revealed that linezolid was more likely to consistently achieve microbiologic eradication in MRSA ME patients. Apparent risks of thrombocytopenia, nausea, diarrhea, and possibly anemia may limit linezolid use in treating MRSA cSSTI. This study was limited due to an inability to assess for the effects of hetero-resistance and appropriate vancomycin dosing on outcomes. Moreover, the small number of studies made controlling for heterogeneity challenging.

Institutional Experience with Daptomycin Treatment in Patients with Gram-Positive Infections

Purpose

Daptomycin was originally approved for the treatment of complicated skin and skin-structure infections caused by gram-positive bacteria, and recently, its indications were expanded to include bacteremia and right-sided infective endocarditis caused by Staphylococcus aureus. This retrospective chart review examines outcomes and costs for individuals treated with daptomycin at a tertiary care medical center.

Methods

During an 11-month period, records of patients treated with daptomycin at the institution were reviewed. Cases for which complete cost data were available were included in the analysis. Outcomes were assigned to 4 categories: cured, improved, failed, or unevaluable. Hospital stay details were recorded, and antibiotic and total hospital treatment costs were calculated.

Results

Thirty-five patients representing 37 cases were included in the review. Of those cases, 89% (33 of 37) involved documented infections with gram-positive bacteria, 22% involved confirmed methicillin-resistant S. aureus infections, and 32% involved confirmed vancomycin-resistant enterococcus infections. Most cases (27 of 37; 73%) involved infections with multiple bacterial isolates for which previous therapy had failed. Of all clinically evaluable cases, 54% were classified as cured and 42% as improved after daptomycin therapy. Median and mean ± standard deviation (SD) total cost of hospitalization were $46,730 and $111,604 ± $137,138, respectively. Overall median duration of therapy for all 37 cases was 14 days (range, 1 to 143; mean ± SD duration, 25.5 ± 32 days).

Conclusion

Daptomycin cured or improved most evaluable gram-positive infections. The results of this study suggest that daptomycin may be considered a therapeutic option for treatment of drug-resistant gram-positive infections.

Cost-effectiveness analysis of linezolid vs. vancomycin in treating methicillin-resistant Staphylococcus aureus complicated skin and soft tissue infections using a decision analytic model

PURPOSE

To evaluate the cost-effectiveness of vancomycin vs. linezolid in complicated skin and soft tissue infections (cSSTIs) with methicillin-resistant Staphylococcus aureus (MRSA) using a decision analytic (DA) model.

METHODS

A DA model was created to evaluate the cost-effectiveness of four treatment strategies in the treatment of MRSA cSSTIs: linezolid intravenous (i.v.) to oral (LIN), vancomycin i.v. inpatient treatment (VAN-1), vancomycin i.v. switch to oral linezolid (VAN-2) and vancomycin i.v. switch to outpatient vancomycin i.v. (VAN-3). Probabilities were determined from published clinical trials. Incremental cost-effectiveness ratios for the various strategies were the primary outcome. Univariate (one-way) sensitivity analysis and second-order Monte Carlo simulation (using 10,000 trials) were conducted for all parameters used in the model.

RESULTS

The DA model predicted that VAN-3 was the most cost-effective strategy from the base-case analysis. Average cost-effectiveness ratio for this strategy was $26,831.42/cure. Univariate sensitivity analysis revealed that the model was sensitive to linezolid duration of inpatient stay and duration of i.v. vancomycin before switching to an oral agent or discharged with outpatient i.v. administration with vancomycin. Probabilistic sensitivity analysis showed that VAN-1 was dominated by LIN, but LIN was only 30% cost-effective compared with VAN-3. Acceptability curve showed that the probability of choosing LIN as a cost-effective strategy compared with VAN-1, VAN-2 and VAN-3 increased as the willingness-to-pay (WTP) increased.

CONCLUSION

Alternative vancomycin strategies (VAN-2 and VAN-3) that take advantage of early discharge opportunities were cost-effective compared with LIN. However, LIN's higher efficacy would make it cost-effective for payers with a high WTP threshold.

Outcomes associated with initial versus later vancomycin use in patients with complicated skin and skin-structure infections

BACKGROUND

Delayed coverage of pathogens including meticillin-resistant Staphylococcus aureus (MRSA) in pneumonia and bacteraemia has been associated with increased mortality and length of hospital stay (LOS). However, less is known about the impact of delayed appropriate coverage in complicated skin and skin-structure infections (cSSSIs).

OBJECTIVE

To evaluate the clinical and economic outcomes associated with early versus late use of vancomycin in the management of patients hospitalized for cSSSIs.

METHODS

Retrospective analysis was performed using an inpatient claims database of >500 US hospitals in 2005. Using prescription claims, patients with primary or secondary cSSSI admissions were classified into three groups: 1 = early vancomycin monotherapy; 2 = early vancomycin combination therapy; 3 = late vancomycin therapy. Outcomes studied included LOS and inpatient hospital costs. One-way analysis of variance was used for unadjusted analysis and multivariate regression methods were used to control for co-variates.

RESULTS

A total of 34,942 patients (27.78% of all patients with cSSSIs) were treated with vancomycin. Mean age was 54.7 years and 54.3% of the patients were males. Mean unadjusted total LOS was 8.46, 9.44 and 13.2 days, and hospital costs in 2005 values were USD10 211.94, USD12 361.94 and USD18 344.00 for groups 1, 2 and 3, respectively. In-hospital mortality rate was highest in group 3 (4.18%) and lowest in group 1 (1.75%). Generalized linear models used to control for potential confounding variables between early versus late vancomycin use suggest that among cSSSI patients late vancomycin use is an independent predictor of higher LOS and costs.

CONCLUSION

In this large inpatient database, later vancomycin use in patients with cSSSIs appears to be significantly associated with higher LOS and total costs.

Observations on vancomycin use in U.S. hospitals

PURPOSE

Current knowledge and policies regarding vancomycin use and the clinical performance of vancomycin in U.S. hospitals were assessed.

METHODS

A questionnaire was sent to interested hospital pharmacists. An observational study of hospitalized adults who received at least 72 hours of i.v. vancomycin for a culture-confirmed gram-positive infection followed. Hospital antibiograms were obtained for gram-positive susceptibility data.

RESULTS

A total of 59 respondents completed the survey. Survey results revealed that vancomycin is rarely restricted. Investigators from 24 hospitals, 16 (67%) of which were teaching facilities, collected retrospective data from the records of 200 patients. Infection sites included blood, lower respiratory tract, and skin and soft tissue. Staphylococcus aureus was isolated from 52% of positive cultures; 75% of these were methicillin-resistant S. aureus (MRSA). Serum vancomycin concentrations were monitored in 95% of patients; results from 22 hospitals were evaluable. Trough serum vancomycin concentrations were higher in teaching versus nonteaching hospitals (p < 0.001). Peak serum vancomycin concentrations were also higher in teaching versus nonteaching hospitals (p < 0.05). Clinical responses from 22 hospitals were evaluable; the mean success rate of 82% did not significantly differ between teaching and nonteaching hospitals. Vancomycin- associated adverse events occurred in 13 patients (6.5%) and were reported more frequently for patients in teaching versus nonteaching hospitals (p = 0.02).

CONCLUSION

Observational data suggest that vancomycin remains an effective antibiotic with infrequent discontinuations due to adverse events, and trough serum vancomycin concentrations are monitored routinely. Antibiogram data revealed that the prevalence of MRSA continues to increase.

Direct costs in patients hospitalised with community-acquired pneumonia after non-response to outpatient treatment with macrolide antibacterials in the US

INTRODUCTION

Antibacterial cost-containment programmes emphasise the use of narrow-spectrum generic agents whenever possible. The use of these agents is driven by their lower purchase prices; the consequences of treatment failure are rarely considered. This study was conducted to identify the costs of treating patients hospitalised with community-acquired pneumonia (CAP) associated with Streptococcus pneumoniae following failure to respond to outpatient treatment with macrolide antibacterials.

METHODS

A multicentre, retrospective, observational study was performed in patients with CAP due to S. pneumoniae who were admitted to 31 North American hospitals following a lack of response to >or=2 days of outpatient treatment with a macrolide antibacterial. Direct medical costs (year 2004 values) of infection-related hospital resources, including antibacterials (purchase, preparation, dispensing, administration and monitoring), diagnostic tests, therapeutic procedures, treatment of adverse events and therapeutic failures, and hospitalisation per diem (ward, critical care and ventilator days), were analysed. Total hospital costs were then compared with standard diagnosis-related group (DRG) reimbursement.

RESULTS

A total of 122 patients were enrolled. Patients were frequently bacteraemic (52%) and infected with macrolide-resistant strains of S. pneumoniae (71%). Initial inpatient antibacterial treatment was not successful in 17 patients (14%) and seven patients (5.7%) died. The mean length of stay was 8.7 days (SD 7) including 1.3 days (SD 2.9) in a critical care unit and 1.4 days (SD 4.4) of mechanical ventilation. The mean cost of hospitalisation was US dollars 12,678 (SD 13 346) but standard DRG reimbursement averaged only US dollars 8,634.

CONCLUSIONS

Patients who do not respond to outpatient treatment with a macrolide antibacterial and who are subsequently hospitalised with CAP caused by S. pneumoniae are likely to be infected with a non-susceptible strain, are frequently bacteraemic, are at an increased risk for mortality compared with previously published estimates in patients with CAP due to S. pneumoniae, and incur hospital costs that far exceed standard DRG reimbursement for CAP.

Epidemiology and economic impact of meticillin-resistant Staphylococcus aureus: review and analysis of the literature

In the past 2 decades, meticillin-resistant Staphylococcus aureus (MRSA) has become an increasingly prevalent problem in healthcare, both in acute care institutions and in the community. MRSA is associated with worse outcomes and higher costs for care than meticillin sensitive S. aureus (MSSA). MRSA is a particular problem in several conditions, including hospital-acquired pneumonia (including ventilator-associated pneumonia), skin and soft tissue infections, and diabetic foot infections. Hospitalisation costs associated with MRSA infection are substantially greater than those associated with MSSA infection, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In several countries, infection control programmes have shown potential economic benefits, as savings accruing from strict and effective control have been shown to outweigh the cost of policy implementation. Standard therapy is based on glycopeptide treatment, usually with vancomycin, although resistance to this agent has emerged. Alternative available treatments for MRSA include teicoplanin, tigecycline, daptomycin, quinupristin-dalfopristin and the oxazolidinone, linezolid, which has a higher acquisition cost than vancomycin but is available as intravenous and oral formulations. Despite some limitations of analyses to date, linezolid has been shown to be cost effective in the treatment of MRSA and appears to be related, in part, to the drug's potential for facilitating earlier discharge from hospital. Current opinion favours rational prescribing to maximise therapeutic benefit and minimise the risk of further antibacterial resistance.

Methicillin-resistant Staphylococcus aureus: A public health issue with economic consequences

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) has become endemic worldwide in hospitals, and community-associated MRSA is spreading into the community at large.

OBJECTIVES

To estimate the current cost of MRSA in Canada and to assess the magnitude of this public health issue.

METHODS

An extensive review of the literature was conducted to gather epidemiology, health care resource utilization and cost data for MRSA in Canadian settings. The current MRSA burden was estimated using available cost data and the most recent epidemiology data.

RESULTS

The rate of MRSA in Canadian hospitals increased from 0.46 to 5.90 per 1000 admissions between 1995 and 2004, while community-associated MRSA continued to spread into the community. Patients harbouring MRSA required prolonged hospitalization (average 26 days of isolation per patient), special control measures, expensive treatments and extensive surveillance. Total cost per infected MRSA patient averaged $12,216, with hospitalization being the major cost driver (81%), followed by barrier precautions (13%), antimicrobial therapy (4%) and laboratory investigations (2%). The most recent epidemiological data, combined with available cost data, suggest that direct health care cost attributable to MRSA in Canada, including cost for management of MRSA-infected and-colonized patients and MRSA infrastructure, averaged $82 million in 2004 and could reach $129 million in 2010.

CONCLUSION

MRSA is a costly public health issue that needs to be tackled if the growing burden of this disease in Canadian hospitals and in the community is to be limited.

Gram-positive cocci infections in intensive care: guide to antibacterial selection

The incidence of multiresistance in Gram-positive cocci causing infections in critically ill patients admitted to the intensive care unit (ICU) has increased notably in recent years. Thus, therapeutic proposals have been modified according to the emergence of multiresistant cocci and adapted to epidemiological markers of individual infectious processes, geographical variations of these markers, the availability of new antibacterials, and advances in the knowledge of pharmacokinetic and pharmacodynamic aspects of their use. The current management of critically ill patients should consider new therapeutic approaches, such as the "de-escalating strategy", which includes the administration of empirical antibacterials active against multiresistant pathogens followed by directed treatment based on unequivocal data from antibacterial-susceptibility testing. Optimisation of antibacterial treatment should be viewed in the context of the need to determine plasma drug concentrations, pharmacoeconomic considerations and control of drug-related adverse events. Therapeutic proposals should be developed within the framework of the antibacterial policy of each hospital. The present review is focused on the description of the therapeutic strategies for the main infectious processes caused by Gram-positive cocci in severely ill patients admitted to the ICU according to a review of the pertinent literature and the clinical experience of the authors.

Daptomycin for treating infected diabetic foot ulcers: evidence from a randomized, controlled trial comparing daptomycin with vancomycin or semi-synthetic penicillins for complicated skin and skin-structure infections

OBJECTIVES

The predominant pathogens causing diabetic foot infections are Gram-positive cocci, many of which are now resistant to commonly prescribed antibiotics. Daptomycin is a new agent that is active against most Gram-positive pathogens. To compare the effectiveness of daptomycin against semi-synthetic penicillins or vancomycin, we analysed the subset of diabetic patients with an infected ulcer enrolled in two randomized, controlled investigator-blind trials of patients with complicated skin and soft-tissue infections presumptively caused by Gram-positive organisms.

PATIENTS AND METHODS

Patients with a diabetic ulcer infection were prospectively stratified to ensure they were equally represented in the treatment groups, then randomized to either daptomycin [4 mg/kg every 24 h intravenously (iv)] or a pre-selected comparator (vancomycin or a semi-synthetic penicillin) for 7-14 days.

RESULTS

Among 133 patients with a diabetic ulcer infection, 103 were clinically evaluable; 47 received daptomycin and 56 received a comparator. Most infections were monomicrobial, and Staphylococcus aureus was the predominant pathogen. Success rates for patients treated with daptomycin or the comparators were not statistically different for clinical (66% versus 70%, respectively; 95% CI, -14.4, 21.8) or microbiological (overall or by pathogen) outcomes. Both treatments were generally well tolerated, with most adverse events of mild to moderate severity.

CONCLUSIONS

The clinical and microbiological efficacy and safety of daptomycin were similar to those of commonly used comparator antibiotics for treating infected diabetic foot ulcers caused by Gram-positive pathogens. Daptomycin should be considered for treating these infections, especially those caused by resistant Gram-positive pathogens.