The economic impact of methicillin-resistant Staphylococcus aureus in Canadian hospitals

OBJECTIVES

To determine the costs associated with the management of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA), and to estimate the economic burden associated with MRSA in Canadian hospitals.

DESIGN

Patient-specific costs were used to determine the attributable cost of MRSA associated with excess hospitalization and concurrent treatment. Excess hospitalization for infected patients was identified using the Appropriateness Evaluation Protocol, a criterion-based chart review process to determine the need for each day of hospitalization. Concurrent treatment costs were identified through chart review for days in isolation, antimicrobial therapy, and MRSA screening tests. The economic burden to Canadian hospitals was estimated based on 3,167,521 hospital discharges for 1996 and 1997 and an incidence of 4.12 MRSA cases per 1,000 admissions.

SETTING

A tertiary-care, university-affiliated teaching hospital in Toronto, Ontario, Canada.

PATIENTS

Inpatients with at least one culture yielding MRSA between April 1996 and March 1998.

RESULTS

A total of 20 patients with MRSA infections and 79 colonized patients (with 94 admissions) were identified. This represented a rate of 2.9 MRSA cases per 1,000 admissions. The mean number of additional hospital days attributable to MRSA infection was 14, with 11 admissions having at least 1 attributable day. The total attributable cost to treat MRSA infections was $287,200, or $14,360 per patient The cost for isolation and management of colonized patients was $128,095, or $1,363 per admission. Costs for MRSA screening in the hospital were $109,813. Assuming an infection rate of 10% to 20%, we determined the costs associated with MRSA in Canadian hospitals to be $42 million to $59 million annually.

CONCLUSIONS

These results indicate that there is a substantial economic burden associated with MRSA in Canadian hospitals. These costs will continue to rise if the incidence of MRSA increases further.

Clinical effectiveness and cost-effectiveness of 2 management strategies for infected total hip arthroplasty in the elderly

Optimal management of infected total hip arthroplasty poses a major challenge to clinicians. Exchange arthroplasty is usually advocated but has high rates of surgical morbidity and is expensive. Debridement with prosthesis retention is associated with less morbidity, but high rates of relapsed infection have been described. To estimate the effectiveness and cost-effectiveness of these 2 strategies among older patients, we used a Markov model to simulate patients' projected lifetime clinical course in hypothetical cohorts of 65-year-old and frail 80-year-old men and women. Initial debridement and retention increased life expectancy 2.2-2.6 quality-adjusted life months and had a favorable cost-effectiveness ratio in all cohorts. Results were most sensitive to the annual rate of relapse after debridement and age at initial diagnosis of infection. In the absence of prospective clinical trials, debridement and retention is a reasonable strategy for treatment of older persons with staphylococcal or streptococcal infection and a nonloosened prosthesis.

Clinical consequences and cost of limiting use of vancomycin for perioperative prophylaxis: example of coronary artery bypass surgery

Routine us of vancomycin for perioperative prophylaxis is discouraged, principally to minimize microbial resistance to it. However, outcomes and costs of this recommendation have not been assessed. We used decision-analytic models to compare clinical results and cost-effectiveness of no prophylaxis, cefazolin, and vancomycin, in coronary artery bypass graft surgery. In the base case, vancomycin resulted in 7% fewer surgical site infections and 1% lower all-cause mortality and saved $117 per procedure, compared with cefazolin. Cefazolin, in turn, resulted in substantially fewer infections and deaths and lower costs than no prophylaxis. We conclude that perioperative antibiotic prophylaxis with vancomycin is usually more effective and less expensive than cefazolin. Data on vancomycin's impact on resistance are needed to quantify the trade-off between individual patients' improved clinical outcomes and lower costs and the future long-term consequences to society.

Methicillin-resistant Staphylococcus aureus (MRSA): is there a need to change clinical practice?

Methicillin-resistant Staphylococcus aureus (MRSA) is a virulent organism that causes significant mortality and morbidity especially to patients in critical care areas (CCAs). MRSA can (and does in some cases) also contribute to an increased length of hospital stay and higher health care costs. The literature proposes that routine screening of patients in CCAs is an effective strategy to control MRSA. Furthermore, placing patients in contact isolation until screening results are confirmed can prevent the spread of MRSA. The policies for management of MRSA patients and the incidence of MRSA infection vary widely. The preliminary findings from this review suggest that a uniform policy regarding routine screening and infection control management for all CCA patients should be recommended. A uniform policy has the potential to reduce rates of infection, cross-contamination and associated health costs attributed to MRSA management. However, further research is required before changes to infection control policy can be recommended. The outcomes from this review will be used to increase staff awareness of current infection control practices for MRSA patients in critical care areas and encourage further research.

Diagnosis of MRSA with neural networks and logistic regression approach

Antibiotic-resistant pathogens are increasingly prevalent in the hospitals and community. A timely and accurate diagnosis of the infection would greatly help physicians effectively treat patients. In this research we investigate the potential of using neural networks (NN) and logistic regression (LR) approach in diagnosing methicillin-resistant Staphylococcus aureus (MRSA). Receiver-Operating Characteristic (ROC) curve and the cross-validation method are used to compare the performances of both systems. We found that NN is better than the logistic regression approach, in terms of both the discriminatory power and the robustness. With modeling flexibility inherent in its techniques, NN is effective in dealing with MRSA and other classification problems involving large numbers of variables and interaction complexity. On the other hand, logistic regression in our case is slightly inferior, offers more clarity and less perplexity. It could be a method of choice when fewer variables are involved and/or justification of the results is desired.

The clinical and economic impact of deep chest surgical site infections following coronary artery bypass graft surgery

STUDY OBJECTIVES

To examine how deep chest surgical site infections following coronary artery bypass graft (CABG) surgery impact hospital inpatient length of stay (LOS), costs, and mortality.

SETTING

A large, Midwestern community medical center.

DESIGN

All CABG patients who developed deep chest infection (n = 41) were compared to a set of control subjects (n = 160) systematically selected as every tenth uninfected CABG patient. Clinical data were abstracted from patient records, and cost information was obtained from the cost accounting database of the hospital.

RESULTS

Variables that significantly increased the risk of deep chest surgical site infection included obesity (odds ratio [OR], 11; p = 0. 0001), renal insufficiency (OR, 8.9; p = 0.0001), connective tissue disease (OR, 25.4; p = 0.0003), reexploration for bleeding (OR, 8.2; p = 0.0015), and the timing of antibiotic prophylaxis (> 60 min before incision; OR, 5.3; p = 0.0128). Within 1 year postoperatively, patients with deep chest surgical site infection had a mortality rate of 22%, vs 0.6% for uninfected patients (p = 0.0001). Infected patients also incurred an average of 20 additional hospital days (p = 0.0001). Univariate analysis indicated that patients who developed deep chest surgical site infection incurred $20,012 in additional costs in the first year (p = 0.0001). Infected patients who died incurred on average $60,547 more than infected patients who survived (p = 0.034). Multivariate analysis confirmed the magnitude of the estimate of the cost for deep chest surgical site infection ($18, 938; p = 0.0001).

CONCLUSIONS

Deep chest surgical site infections following CABG surgery are associated with significant increases in LOS, hospitalization costs, and mortality. These results suggest the need for improved infection control measures to reduce deep chest surgical site infection rates.

Corrigendum to "A linear programming assessment of the profit from strategies to reduce the prevalence of Staphylococcus aureus mastitis" [Prev. Vet. Med. 33 (1998) 183-193]

We used a linear programming model to estimate the financial returns to a Staphylococcus aureus testing and control program over a 1-year period for a 100-cow herd, with a 8636kg rolling-herd average. Six tests, which vary in sensitivity from 0.80 to 0.98 and specificity of 0.99, were examined in simulated herds with 10, 20, and 30% prevalence of S. aureus infection. Sensitivity of these results to a range of assumptions regarding rolling-herd average, milk price, somatic cell-count premium, and cost and cure rate of dry treatment were examined to determine the profits from the program. The profits of a control program are most dependent upon prevalence and cell-count premium. In our simulation for a 100-cow herd, a testing and control program results in a profit ranging from US$1.50 to US$20 per cow per year, except under the lowest prevalence and most-adverse conditions (low yield or low SCC premium).

Urinary tract infections, antibiotic resistance and sales of antimicrobial drugs--an observational study of uncomplicated urinary tract infections in Icelandic women

OBJECTIVES

To analyse the antimicrobial susceptibility pattern of bacteria causing symptomatic but otherwise uncomplicated lower urinary tract infections (UTI) in primary health care and the sales of antimicrobial drugs.

SETTING

Primary health care in Akureyri District, Northern Iceland, with about 17400 inhabitants.

PATIENTS

A total of 516 episodes of symptomatic but otherwise uncomplicated lower UTI in women 10 to 69 years of age.

MAIN OUTCOME MEASURES

Number of verified UTI, bacterial species, antimicrobial susceptibility pattern, and total sales of antimicrobial drugs.

RESULTS

Escherichia coli was by far the most common cause of UTI (83%), followed by Staphylococcus saprophyticus (7%). Infections caused by E. coli resistant to ampicillin accounted for 36% of cases, with the corresponding figures for sulfafurazol being 37%, cephalothin 45%, trimethoprim 13% and mecillinam 14%. Only 1% of the strains were resistant to nitrofurantoin. The total use of antimicrobial drugs was 17.4 DDD/1000 inhabitants/day.

CONCLUSIONS

The resistance of bacteria causing uncomplicated UTI to common antimicrobials is high and must be taken into account when selecting treatment strategies. High consumption of antibiotics in the community indicates possible association.

Control of endemic methicillin-resistant Staphylococcus aureus: a cost-benefit analysis in an intensive care unit

CONTEXT

Despite the success of some countries in controlling endemic methicillin-resistant Staphylococcus aureus (MRSA), such programs have not been implemented for some hospitals with endemic infection because of concerns that these programs would be costly and of limited benefit.

OBJECTIVE

To compare the costs and benefits of an MRSA control program in an endemic setting.

DESIGN AND SETTING

Case-control study conducted at a medical intensive care unit (ICU) of a French university hospital with a 4% prevalence of MRSA carriage at ICU admission.

PATIENTS

Twenty-seven randomly selected patients who had ICU-acquired MRSA infection between January 1993 and June 1997, matched to 27 controls hospitalized during the same period without MRSA infection.

MAIN OUTCOME MEASURES

Intensive care unit costs attributable to MRSA infection, computed from excess therapeutic intensity in cases using estimates from a cost model derived in the same ICU, were compared with costs of the control program, derived from time-motion study of nurses and physicians. The threshold for MRSA carriage that would make the control strategy dominant was determined; sensitivity analyses varied rates of MRSA transmission and ratio of infection to transmission, length of ICU stay, and costs of isolation precautions.

RESULTS

The mean cost attributable to MRSA infection was US $9275 (median, $5885; interquartile range, $1400-$16,720). Total costs of the control program ranged from $340 to $1480 per patient. A 14% reduction in MRSA infection rate resulted in the control program being beneficial. In sensitivity analyses, the control strategy was dominant for a prevalence of MRSA carriage on ICU admission ranging from 1% to 7%, depending on costs of control measures and MRSA transmission, for infection rates greater than 50% following transmission.

CONCLUSIONS

In this example of a hospital with endemic MRSA infection, selective screening and isolation of carriers on ICU admission are beneficial compared with no isolation.

[Cost analysis concerning MRSA-infection in ICU]

OBJECTIVE

MRSA-infection incidences are still rising, because of unreflected use of antibiotic drugs in man and animals. Although some European countries already have an incidence as high as 30% of MRSA infection in ICU-patients, there is no additional financial support for the treatment of MRSA infected patients.

METHODS

We investigated all MRSA infected patients of the operative ICU ward of the department of anaesthesia at the university Ulm within the last three years. We calculated all costs for decontamination and special treatment of the MRSA infection as well as the costs for closing beds, because of MRSA precaution and isolation reasons.

RESULTS

The average monthly costs for MRSA infected patients is about 3848 EURO for decontamination and treatment, and another 5560 EURO fix costs. The average monthly ICU duration for MRSA patients was 5.8 days, which means a financial loss of 1622 EURO per "MRSA-patient day". This loss is more than two times the price the social security system pays for an ICU-patient.

CONCLUSION

These extra costs should be calculated and additionally paid for patients with MRSA-infection in order to obtain a certain quality standard. By achieving this standard the total economy costs for MRSA infection treatment could be reduced.

Nosocomial methicillin-resistant and methicillin-susceptible Staphylococcus aureus primary bacteremia: at what costs?

OBJECTIVE

To determine the attributable hospital stay and costs for nosocomial methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) primary bloodstream infections (BSIs).

DESIGN

Pairwise-matched (1:1) nested case-control study.

SETTING

University-based tertiary-care medical center.

PATIENTS

Patients admitted between December 1993 and March 1995 were eligible. Cases were defined as patients with a primary nosocomial S. aureus BSI; controls were selected according to a priori matching criteria.

MEASUREMENTS

Length of hospital stay and total and variable direct costs of hospitalization.

RESULTS

The median hospital stay attributable to primary nosocomial MSSA BSI was 4 days, compared with 12 days for MRSA (P=.023). Attributable median total cost for MSSA primary nosocomial BSIs was $9,661 versus $27,083 for MRSA nosocomial infections (P=.043).

CONCLUSION

Nosocomial primary BSI due to S. aureus significantly prolongs the hospital stay. Primary nosocomial BSIs due to MRSA result in an approximate threefold increase in direct cost, compared with those due to MSSA.

Head-injured patients who are nasal carriers of Staphylococcus aureus are at high risk for Staphylococcus aureus pneumonia

OBJECTIVE

To determine if head-injured patients with premorbid nasal colonization with Staphylococcus aureus are at increased risk for S. aureus infection.

DESIGN

Patients admitted over a 2-yr period were enrolled if they met the following criteria: Injury Severity Score > or = 9, intensive care unit (ICU) admission, hospitalization in another hospital < 24 hrs, no recent use of antibiotics.

SETTING

Acute care trauma facility.

PATIENTS

Any patient sustaining acute, blunt, or penetrating injury and meeting the enrollement criteria were eligible.

INTERVENTIONS

Swab cultures of both internal nares were performed within 72 hrs of readmission and cultured for S. Aureus. Patients were prospectively monitored for S. Aureus infections until discharge.

MEASUREMENTS AND MAIN RESULTS

Admission nasal cultures were positive (NC+) for S. aureus in 144 of the 776 patients cultured. Forty of the 144 NC+ patients had isolated head (37) or high cervical spine (3) injury, and 11 of that group (27.5%) developed S. aureus infections. The remaining 104 patients positive for S. aureus on admission had no head injury (74) or head combined with torso and extremity injuries (30). S. aureus infection was diagnosed in 11 of the 104 patients (10.6%). The difference in incidence of infections is significant (p <.01), as is the difference in incidence of pneumonia (20% vs. 3.8%, respectively [p <.01]). Organisms causing pneumonia were often the same organisms isolated from the nares on admission.

CONCLUSIONS

Nasal colonization with S. aureus at the time of severe head injury increases the risk of S. aureus pneumonia during hospitalization. Prophylactic measures against S. aureus pneumonia may help reduce the length and cost of hospitalization.

The economic impact of Staphylococcus aureus infection in New York City hospitals

We modeled estimates of the incidence, deaths, and direct medical costs of Staphylococcus aureus infections in hospitalized patients in the New York City metropolitan area in 1995 by using hospital discharge data collected by the New York State Department of Health and standard sources for the costs of health care. We also examined the relative impact of methicillin-resistant versus -sensitive strains of S. aureus and of community-acquired versus nosocomial infections. S. aureus-associated hospitalizations resulted in approximately twice the length of stay, deaths, and medical costs of typical hospitalizations; methicillin-resistant and -sensitive infections had similar direct medical costs, but resistant infections caused more deaths (21% versus 8%). Community-acquired and nosocomial infections had similar death rates, but community-acquired infections appeared to have increased direct medical costs per patient ($35,300 versus $28,800). The results of our study indicate that reducing the incidence of methicillin-resistant and -sensitive nosocomial infections would reduce the societal costs of S. aureus infection.

Cost-effectiveness of prophylactic nasal mupirocin in patients undergoing peritoneal dialysis based on a randomized, placebo-controlled trial

The study objective was to measure the benefits of elimination of nasal carriage of Staphylococcus aureus by calcium mupirocin ointment in patients undergoing continuous ambulatory peritoneal dialysis. The design was a prospective, placebo-controlled, randomized clinical trial. The subjects were 267 patients recruited from nine renal units in Belgium, France and the UK. The main outcome measures were the rate of catheter exit site infection (ESI), rates of other infections and healthcare costs from the perspective of a hospital budget-holder. The rate of ESI caused by S. aureus was significantly reduced from one in 28.1 patient months to one in 99.3 patient months (P = 0.006) and there were also non-significant trends towards lower rates of ESI caused by any organism and peritonitis caused by S. aureus. In comparison with the placebo group, patients in the mupirocin group with ESI had lower antibiotic (P = 0.02) and hospitalization costs (P = 0.065). However, overall costs of antibiotic treatment, for all infections combined, were not significantly different (P = 0.2) and total antibiotic costs (including mupirocin) were significantly higher in the mupirocin group (P = 0.001). Mupirocin prophylaxis would have been cost-neutral if the rate of ESI increased to >75% in the placebo group, or if all healthcare costs increased by 40%, or if the cost of screening was reduced from Pound Sterling 15 to Pound Sterling 3 per patient, or if the cost of mupirocin treatment was reduced from Pound Sterling 93 to Pound Sterling 40 per patient year. In conclusion, savings in healthcare costs are unlikely to be sufficiently great to offset the cost of mupirocin and screening for nasal carriage of S. aureus. The decision about whether or not to implement mupirocin should depend on a local analysis of the value of preventing ESIs caused by S. aureus.

Eradication of nasal carriage of Staphylococcus aureus--is it cost-effective?

In cardiothoracic surgery, the costs of surgical-site infection (SSI) arise from additional postoperative procedures (approximately US $5000 per patient) and prolonged hospital stay (approximately $11,500 per patient). Application of nasal mupirocin reduced SSIs by 63% compared with historical controls. This would have resulted in savings provided that the attributable cost of an SSI was more than $245. Mupirocin was estimated to reduce the risk of bacteraemia in haemodialysis patients by 84% compared with historical controls. A model using data on Medicare payments for haemodialysis admissions was used to estimate the impact on hospital costs. The conclusion was that mupirocin would have been cost-saving but the model did not provide sufficient detail about hospital costing to allow assessment of its relevance in other settings. In a prospective, randomized, placebo-controlled trial in continuous ambulatory peritoneal dialysis (CAPD) patients, mupirocin reduced the risk of staphylococcal exit-site infection (ESI) from 0.42 to 0.14 per patient-year. However, as in a previous comparison with historical controls, there was an increase in the rates of ESIs caused by Gram-negative bacteria in patients who received mupirocin, bringing the rate of total ESIs up to that observed in the placebo group. There was some evidence that infections caused by Gram-negative bacteria had less severe consequences than staphylococcal infections. It is concluded that application of nasal mupirocin to nasal carriers of Staphylococcus aureus may be cost-saving in patients undergoing cardiac surgery or haemodialysis but, if the analysis is restricted to the cost of management of ESIs, it may not be cost-saving in CAPD. However, reducing the risk of staphylococcal ESI may reduce the risk of catheter loss and subsequent transfer to haemodialysis and this merits further study.

Partial budget of the discounted annual benefit of mastitis control strategies

The objective of this study was to rank the benefits associated with various mastitis control strategies in simulated herds with intramammary infections caused by Streptococcus agalactiae, Streptococcus spp. other than Strep. agalactiae, Staphylococcus aureus, coagulase-negative staphylococci, and Escherichia coli. The control strategies tested were prevention, vaccination for E. coli, lactation therapy, and dry cow antibiotic therapy. Partial budgets were based on changes caused by mastitis control strategies from the mean values for milk, fat, and protein yields of the control herd and the number of cows that were culled under a fixed mastitis culling criterion. Each annual benefit (dollars per cow per year) of a mastitis control strategy was compared with the revenue for the control herd and was calculated under two different milk pricing plans (3.5% milk fat and multiple-component pricing), three net replacement costs, and three prevalences of pathogen-specific intramammary infection. Twenty replicates of each control strategy were run with SIMMAST (a dynamic discrete event stochastic simulation model) for 5 simulated yr. Rankings of discounted annual benefits differed only slightly according to milk pricing plans within a pathogen group but differed among the pathogen groups. Differences in net replacement costs for cows culled because of mastitis did not change the ranking of control strategies within a pathogen group. Both prevention and dry cow therapy were important mastitis control strategies. For herds primarily infected with environmental pathogens, strategies that included vaccination for mastitis caused by E. coli dominated strategies that did not include vaccination against this microorganism.

C-reactive protein levels in the extremely premature infant: case studies and literature review

Sepsis continues to be a significant source of morbidity and mortality in the neonatal intensive unit. At the same time, we need to contain medical costs and prevent the rapid growth of resistant organisms by limiting unnecessary antibiotic use. Among laboratory indexes studied as indirect indicators of the presence and resolution of infection and inflammation, C-reactive protein (CRP) has gained more recent widespread use. CRP usually increases in a delayed manner with the onset of inflammation and decreases as inflammation resolves. We follow serial CRP values in our neonatal intensive care unit from the start of a sepsis evaluation until antibiotic therapy is withdrawn. We describe two extremely low birth weight patients who improved clinically with therapy and whose CRP levels normalized in the face of continued positive blood cultures. The implications for the use of CRP in deciding when to halt therapy in premature infants are discussed.

Staphylococcus aureus bacteremia: the cost-effectiveness of long-term therapy associated with infectious diseases consultation

OBJECTIVE

To investigate the cost-effectiveness of long-term therapy for Staphylococcus aureus bacteremia and to determine if an infectious diseases consultation affected the duration of therapy.

METHODS

A decision analysis was performed based on data from the literature. To determine if consultation was related to therapy duration, a retrospective cohort study was performed using tightly matched pairs.

RESULTS

The excess cost per life saved by long-term antibiotics was $500,000. The excess cost per life-year saved was $18,000. Nine pairs were matched. Patients who received consultation were more likely to receive long-term therapy than controls (median 41 days vs 15 days for controls, P = .04).

CONCLUSIONS

The estimated cost per life-year saved by long-term therapy was similar to other accepted medical interventions. Infectious diseases consultation can encourage prolonged duration of antibiotic therapy for S aureus bacteremia.

A linear programming assessment of the profit from strategies to reduce the prevalence of Staphylococcus aureus mastitis

We used a linear programming model to estimate the financial returns to a Staphylococcus aureus testing and control program over a 1-year period for a 100-cow herd, with a 8636-kg rolling-herd average. Six tests, which vary in sensitivity from 0.80 to 0.98 and specificity of 0.99, were examined in simulated herds with 10, 20 and 30% prevalence of S. aureus infection. Sensitivity of these results to a range of assumptions regarding rolling-herd average, milk price, somatic cell-count premium, and cost and cure rate of dry treatment were examined to determine the profits from the program. The profits of a control program are most dependent upon prevalence, cell-count premium, and cost of dry treatment. In our simulation for a 100-cow herd, a testing and control program appears to cost less than US$10 per cow per year, and pays for itself within 1 yr, except under the lowest prevalence and most-adverse conditions (low yield, high cost of dry treatment, or low SCC premium.

Cumulative yield from patient surveillance cultures for methicillin-resistant Staphylococcus aureus during a hospital outbreak

The cumulative yield from cultures of separate sites was determined during the investigation of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak. Surveillance cultures were submitted from clinical sites, nose, groin, and axilla of 421 patients on two different occasions. MRSA was recovered most often from various clinical sites, including lower respiratory tract, surgical wounds, urinary tract, and decubitus ulcers (total, 13 patients). Four additional patients were identified as positive from the first nasal swab, one patient from the second nasal swab, and two others from swabs of the groin. The submission of axillary swabs or a second groin swab did not identify additional MRSA-colonized patients and resulted in additional costs of $4,525.

Much ado about nothing: methicillin-resistant Staphylococcus aureus

The pathogenic methicillin-resistant Staphylococcus aureus (MRSA) has received a voluminous amount of notoriety. The four major reasons are its morbidity, mortality rate, cost of treatment, and constant appearance in intensive care units. Both Staphylococcus aureus and S. epidermidis (MRSE) account for 82% of our gram-positive wound isolates, whereas the gram-negative account for 34% of all isolates. Therefore we compared the morbidity, mortality rate, and cost factors related to MRSA-MRSE and gram-negative infections for a 4-year period, assessing more than 214 documented infections. Morbidity and mortality rates were minor for MRSA. Pseudomonas aeruginosa and Escherichia coli accounted for 57.5% of the total gram-negative isolates. Gram-negative antimicrobial therapy usually requires two therapeutic drugs, which increases morbidity and costs, whereas the staphylococci usually can be treated by one antimicrobial. During this period there were 47 gram-negative infections requiring 10 to 15 additional days of hospital stay, with a daily antibiotic cost of $293.40. Costs for MRSA or MRSE are 28% less. Therefore our preoccupation with MRSA or MRSE infections is unwarranted and unsubstantiated.

The treatment of staphylococcal infections with special reference to pharmacokinetic, pharmacodynamic and pharmacoeconomic considerations

The choice of antibiotics for the treatment of staphylococcal infections depends to a high degree on the susceptibility patterns in the hospital in question. These may be highly variable and considerable differences between countries and hospitals exist. The insight into the pharmacodynamic aspects of antimicrobial agents has increased considerably in the last 5 years, resulting in new treatments, such as once daily administration of aminoglycosides and continuous infusion of betalactam antibiotics. The antibiotic policy in Dutch hospitals for the treatment of staphylococcal infections is discussed. In most Western countries with a relatively low incidence of MRSA, penicillin-derivatives, such as flucloxacillin (or cloxacillin, methicillin and nafcillin) will be the drug of choice, because of their good in-vitro activity, low toxicity, good clinical efficacy and relatively low cost. If the incidence of MRSA increases, drugs such as the glycopeptides will be of more importance. This will of course have a clear economic impact, as both vancomycin and teicoplanin are considerably more expensive than agents such as flucloxacillin and oral treatment is not possible. Pharmacoeconomic aspects also play a role. As a rule, intravenous antimicrobial agents are considerably more expensive than the oral formulations. Before oral administration can be recommended, a reliable oral absorption, also in seriously ill patients, must have been demonstrated. Other aspects that influence the cost of therapy are hospital stay and the possibility of outpatient treatment.

Clinical and economic effects of mupirocin calcium on preventing Staphylococcus aureus infection in hemodialysis patients: a decision analysis

This study was performed to determine the clinical and economic consequences of alternative strategies of preventing Staphylococcus aureus infection in chronic hemodialysis patients by use of intranasal mupirocin calcium to clear nasal carriage of S aureus. Decision analysis evaluated clinical outcomes and cost-effectiveness of three likely management strategies to address S aureus nasal carriage and prevent subsequent infection in chronic ambulatory hemodialysis patients: (1) screen for S aureus nasal carriage every 3 months and treat those with a positive test result with mupirocin calcium; (2) treat all patients weekly with mupirocin calcium; or (3) no prevention strategy, treat infection only. Rates of nasal carriage of S aureus, S aureus infection rates, proportion of infections attributable to nasal carriage, efficacy of mupirocin, natural history of infection, and patient management strategies were derived from the published literature and supplemented by a panel of experts. Actual payments for medical services were obtained from Medicare parts A and B. Incremental cost-effectiveness was calculated from the perspective of Medicare and subjected to sensitivity analyses. Assuming that 75% of S aureus infections are attributable to nasal carriage in hemodialysis patients, eliminating nasal carriage of S aureus with mupirocin calcium (with or without screening) markedly reduces the number of infections (45% to 55%) and also reduces health care expenditures relative to treating infections when they occur. Annual savings to Medicare are $784,000 to $1,117,000 per 1,000 hemodialysis patients, depending on the prevention strategy. Preventing S aureus infection by eradicating nasal carriage in chronic hemodialysis patients reduces morbidity while simultaneously reducing medical care costs. The decision to eliminate nasal carriage on a regular basis or use a screening test to guide antibiotic therapy is dependent on the tradeoff between improved short-term clinical and cost benefits and the potential for bacterial resistance that may arise from widespread use of mupirocin calcium.