Retrospective Analysis of Clinical and Cost Outcomes Associated with Methicillin-Resistant Staphylococcus aureus Complicated Skin and Skin Structure Infections Treated with Daptomycin, Vancomycin, or Linezolid

Cost-effectiveness and pricing of antibacterial drugs

Growing resistance to antibacterial agents has increased the need for the development of new drugs to treat bacterial infections. Given increasing pressure on limited health budgets, it is important to study the cost-effectiveness of these drugs, as well as their safety and efficacy, to find out whether or not they provide value for money and should be reimbursed. In this article, we systematically reviewed 38 cost-effectiveness analyses of new antibacterial agents. Most studies showed the new antibacterial drugs were cost-effective compared to older generation drugs. Drug pricing is a complicated process, involving different stakeholders, and has a large influence on cost-effectiveness. Value-based pricing is a method to determine the price of a drug at which it can be cost-effective. It is currently unclear what the influence of value-based pricing will be on the prices of new antibacterial agents, but an important factor will be the definition of ‘value’, which as well as the impact of the drug on patient health might also include other factors such as wider social impact and the health impact of disease.

Economic features of antibiotic resistance: the case of methicillin-resistant Staphylococcus aureus

This paper analyses and updates the economic information regarding methicillin-resistant Staphylococcus aureus (MRSA), including information that has been previously reviewed by other authors, and new information, for the purpose of facilitating health management and clinical decisions. The analysed articles reveal great disparity in the economic burden on MRSA patients; this is mainly due to the diversity of the designs of the studies, as well as the variability of the patients and the differences in health care systems. Regarding prophylactic strategies, the studies do not provide conclusive results that could unambiguously orientate health management. The studies addressing treatments noted that linezolid seems to be a cost-effective treatment for MRSA, mostly because it is associated with a shorter length of stay (LOS) in hospital. However, important variables such as antimicrobial susceptibility, infection type and resistance emergence should be included in these analyses before a conclusion is reached regarding which treatment is the best (most efficient). The reviewed studies found that rapid MRSA detection, using molecular techniques, is an efficient technique to control MRSA. As a general conclusion, the management of MRSA infections implicates important economic costs for hospitals, as they result in higher direct costs and longer LOS than those related to methicillin-susceptible S. aureus (MSSA) patients or MRSA-free patients; there is wide variability in those increased costs, depending on different variables. Moreover, the research reveals a lack of studies on other related topics, such as the economic implications of changes in MRSA epidemiology (community patients and lineages associated with farm animals).

Cost comparison of linezolid versus vancomycin for treatment of complicated skin and skin-structure infection caused by methicillin-resistant Staphylococcus aureus in Quebec

BACKGROUND

In Canada, complicated skin and skin-structure infection (cSSSI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

OBJECTIVES

To evaluate the potential treatment cost impact for the Quebec health care system of linezolid versus vancomycin for MRSA-related cSSSI therapy, using a net impact analysis approach.

METHODS

Health care resource use associated with linezolid and vancomycin therapy was estimated for patients in Quebec, based on expert opinion. Costs were assigned to health care resources (antibiotics, medical supplies, laboratory testing and health care professional time) based on unit prices. The base-case analysis assumed 14 days of antibiotic treatment for both agents; five days in hospital followed by nine days at home. Therapy duration, length of inpatient treatment and discharge rates were varied in sensitivity analyses.

RESULTS

Antibiotic costs were higher for linezolid than for vancomycin, for both inpatient ($874 versus $144, respectively) and outpatient therapy ($1,356 versus $1,242, respectively). Compared with vancomycin, lower costs for antibiotic preparation, administration and monitoring of linezolid offset drug acquisition costs. Total treatment costs were $3,850 for linezolid versus $5,189 for vancomycin. Results were sensitive to the number of treatment days spent at home and the discharge rate.

CONCLUSION

Using linezolid instead of vancomycin to treat MRSA-related cSSSI, for hospital and home courses combined, may reduce health care resource utilization and costs in Quebec.

Comparative analysis of empiric antimicrobial treatments for skin and soft tissue infections in newly hospitalized patients

PURPOSE

Intravenous vancomycin is the standard empiric treatment for complicated skin and soft tissue infections (SSTIs) due to its coverage against methicillin-resistant Staphylococcus aureus (MRSA). The objective of this study was to compare the hospital length of stay (LOS) between vancomycin-treated patients and patients receiving newer anti-MRSA agents. The study also aimed to identify factors associated with therapy change in patients receiving vancomycin on admission.

METHODS

Electronic medical records were used to conduct this retrospective cohort study. The LOS was compared among 5 groups of adult patients with admission diagnoses for SSTI who were initiated on linezolid, daptomycin, ceftaroline, tigecycline, or vancomycin. Survival analysis was used to identify factors associated with therapy change from vancomycin to another study medication.

RESULTS

Vancomycin was prescribed in 1046 (92%) admissions. Although none of the between-group differences in LOS reached statistical significance, there was a trend toward shorter LOS in vancomycin-treated patients compared to linezolid-treated patients (P = .059). Coagulopathy was independently associated with increased likelihood of therapy change from vancomycin (hazard ratio = 4.71; P <.001).

CONCLUSIONS

In the treatment of SSTI, newer agents result in LOS comparable to vancomycin. In patients initiated on vancomycin, therapy change was associated with longer LOS. Coagulopathy was independently associated with increased probability of therapy change.

Ceftaroline fosamil use in hospitalized patients with acute bacterial skin and skin structure infections: Budget impact analysis from a hospital perspective

PURPOSE

The budgetary impact of adding ceftaroline fosamil to a hospital formulary for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) was evaluated.

METHODS

A three-year hospital budget impact model was constructed with three initial treatment options for ABSSSIs: ceftaroline fosamil, vancomycin plus aztreonam, and other vancomycin-containing regimens. The target population was hospitalized adult patients with an ABSSSI. Clinical cure rates with initial treatment were assumed to be similar to those from ceftaroline fosamil clinical trials. Patients who did not respond to initial treatment were assumed to be treated successfully with second-line antimicrobial therapy. Length of stay and cost per hospital day (by success or failure with initial treatment) were estimated based on a large database from more than 100 U.S. hospitals. Other model inputs included the annual number of ABSSSI admissions, projected annual case growth rate, proportion of ABSSSI target population receiving vancomycin-containing regimen, expected proportion of ABSSSI target population to be treated with ceftaroline fosamil, drug acquisition cost, cost of antibiotic administration, and cost of vancomycin monitoring. Sensitivity analysis using 95% confidence limits of clinical cure rates was also performed.

RESULTS

The estimated total cost of care for treating a patient with an ABSSSI was $395 lower with ceftaroline fosamil ($15,087 versus $15,482) compared with vancomycin plus aztreonam and $72 lower ($15,087 versus $15,159) compared with other vancomycin-containing regimens.

CONCLUSION

Model estimates indicated that adding ceftaroline fosamil to the hospital formulary would not have a negative effect on a hospital's budget for ABSSSI treatment.

An evidence-based review of linezolid for the treatment of methicillin-resistant Staphylococcus aureus (MRSA): place in therapy

Methicillin-resistant Staphylococcus aureus (MRSA), including community-associated and hospital-associated strains, is a major cause of human morbidity and mortality. Treatment options have become limited due to the emergence of MRSA strains with decreased sensitivity to vancomycin, which has long been the first-line therapy for serious infections. This has prompted the search for novel antibiotics that are efficacious against MRSA. Linezolid, an oxazolidinone class of antibiotic, was approved by the Food and Drug Administration in 2000 for treatment of MRSA infections. Since then, there have been a multitude of clinical trials and research studies evaluating the effectiveness of linezolid against serious infections, including pneumonia (both community- and hospital-acquired), skin and soft-tissue infections such as diabetic foot ulcers, endocarditis, osteomyelitis, prosthetic devices, and others. The primary aim of this review is to provide an up-to-date evaluation of the clinical evidence for using linezolid to treat MRSA infections, with a focus on recently published studies, including those on nosocomial pneumonia. Other objectives are to analyze the cost-effectiveness of linezolid compared to other agents, and to review the pharmokinetics and pharmacodynamics of linezolid, emphasizing the most current concepts.