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PubMed2006

Mis-specified and non-robust mortality risk models for nasopharyngeal cancer in the National Cancer Institute formaldehyde worker cohort study.

An IARC (International Agency for Research on Cancer) working group categorized formaldehyde as a human carcinogen (Group 1) in 2004. A major component of the epidemiologic evidence evaluated by IARC to reach this decision was the analysis published by Hauptmann et al. [Hauptmann, M., Lubin, J. H., Stewart, P. A., Hayes, R. B., Blair, A. 2004. Mortality from solid cancers among workers in formaldehyde industries. Am. J. Epidemiol. 159, 1117-1130.] of the National Cancer Institute (NCI) historical cohort comprising industrial workers exposed to formaldehyde in 10 U.S. plants. The NCI authors emphasized the relationship found between highest formaldehyde peak exposure and death from nasopharyngeal cancer (NPC). We performed two additional types of re-analyses of the NCI cohort data with focus on peak exposure and NPC mortality. The analyses were aimed at (1) investigating whether the model specification chosen by Hauptmann et al. (2004) was appropriate (interaction assessment) and (2) exploring the degree of instability of the risk estimates for NPC in relation to highest peak exposure (sensitivity analysis). Hauptmann et al. (2004) failed to account for an important interaction structure between plant group and the exposure variable that prohibits a generalization of formaldehyde effects within the NCI cohort and, in particular, beyond the NCI cohort. In addition, our sensitivity analysis demonstrates considerable uncertainties in the risk estimates and points convincingly to instability problems particularly related to Plant 1. Even a simple sensitivity model taking only one additional death into account produced a variation of the risk estimates beyond the instability conveyed by standard confidence intervals. The results of our current reanalysis of the NCI study do not support NCI's suggestion of a causal association with formaldehyde exposure and nasopharyngeal cancer. The decision by the IARC working group to reclassify formaldehyde as a Group 1 substance was clearly premature considering: (1) the missing evidence of an NPC excess from the large British and NIOSH cohort studies; (2) the absence of an association with formaldehyde and NPC in the independent and expanded study of Plant 1; and (3) the mis-specified and non-robust internal analysis of the NCI cohort study brought to light in our current re-analysis. Thus, the 2004 IARC decision to reclassify formaldehyde as a Group 1 substance should be reconsidered.

Adenocarcinoma↗
PubMed2002

Cost-minimization analysis of genetic testing versus clinical screening of at-risk relatives for familial adenomatous polyposis.

OBJECTIVE: Familial adenomatous polyposis (FAP) is a well-known hereditary colorectal cancer-predisposing syndrome. Genetic testing for colorectal cancer risk is now part of standard medical practice, but very little is known about the economic impact of this technology. The aim of this study was to assess, from a healthcare system perspective, the direct costs of two strategies for screening at-risk relatives of FAP patients: clinical screening versus genetic testing for FAP. METHODS: A systematic review of the literature was carried out. Additional information was gathered from experts in research and clinical laboratories and in hospital departments. A decision tree was constructed to compare per-person and per-family costs of the two strategies for screening at-risk relatives of FAP patients. Sensitivity analysis was performed to assess the stability of the model across the full range of plausible values for all key parameters. RESULTS: According to the decision analysis, with FAP screening starting at puberty, the average screening costs are $3,181 and $2,259 (Canadian dollars), respectively, for the clinical screening and the genetic testing strategies. Genetic screening is cost saving up to a first screening age of 36. Sensitivity analysis shows that the results of the baseline analysis hold across a variety of assumptions concerning the parameter values. CONCLUSIONS: The genetic testing strategy is cost saving relative to the clinical screening alternative. Apart from its lower costs, it is associated with many other benefits. Accordingly, under predefined conditions, predictive genetic testing seems to be the optimal screening strategy for FAP.

Adenomatous Polyposis Coli↗
PubMed2006

Lung cancer mortality and carbon black exposure: uncertainties of SMR analyses in a cohort study at a German carbon black production plant.

OBJECTIVE: We undertook a sensitivity analysis of the lung cancer standardized mortality ratios (SMRs) in a study of 1522 German carbon black workers from 1976 to 1998. METHODS: We applied results from a case-control study to adjust the SMR for smoking habits and exposures experienced before the carbon black job. In addition, sensitivity to reference rates was explored. RESULTS: On the basis of 47 lung cancer deaths, the SMRs were 1.62, 1.72, and 2.08 (local, state, and national rates, respectively). Adjustment for previous exposures and smoking yielded additional correction factors of 0.64 or 0.74, varying with the chosen reference. CONCLUSIONS: Lung cancer SMRs (95% confidence intervals) for the full cohort ranged from 1.20 (0.88-1.59) to 2.08 (1.53-2.77) in this sensitivity analysis. Thus, overall SMRs are only weak measures of causal associations and should be complemented by internal modeling of exposure effects whenever possible.

Case-Control Studies↗
PubMed2003

Intravenous levosimendan treatment is cost-effective compared with dobutamine in severe low-output heart failure: an analysis based on the international LIDO trial.

BACKGROUND: Levosimendan, a novel calcium sensitiser, improves cardiac performance and symptoms without increasing oxygen consumption, and decreases the mortality of patients with low-output heart failure. AIMS: To estimate the cost-effectiveness of intravenous treatment with levosimendan compared with dobutamine in patients with severe low-output heart failure. METHODS: This economic evaluation was based on a European clinical trial (LIDO), in which 203 patients with severe heart failure randomly received a 24 h infusion with either levosimendan or dobutamine. Survival and resource utilisation data were collected for 6 months; survival was extrapolated assuming a mean additional lifetime of 3 years based on data from the Cooperative North Scandinavian Enalapril Survival Study trial. Costs were based on study drug usage and hospitalisation in the 6-month follow-up. A sensitivity analysis on dosage of drug and duration of survival was performed. RESULTS: The mean survival over 6 months was 157+/-52 days in the levosimendan group and 139+/-64 days in the dobutamine group (P<0.01). When extrapolated up to 3 years, the gain in life expectancy was estimated at 0.35 years (discounted at 3%). Levosimendan increased the mean cost per patient by 1108, which was entirely due to the cost of the study drug. The incremental cost per life-year saved (LYS) was 3205 at the European level; in the individual countries the cost per LYS ranged between 3091 and 3331. The result was robust in the sensitivity analysis. CONCLUSIONS: Although the patients in the levosimendan group were alive for more days and thus at risk of hospitalisation for longer, there was no increase in hospitalisation or hospitalisation costs with levosimendan treatment. The cost per LYS using levosimendan compares favourably with other cost-effectiveness analyses in cardiology.

Aged↗
PubMed1997

Potential and limitations of radioimmunodetection and radioimmunotherapy with monoclonal antibodies.

UNLABELLED: Recently, we developed a physiologically based pharmacokinetic model capable of predicting antibody biodistribution in humans by scaling up from mice. By applying this model to anticarcinoembryonic antigen murine antibody ZCE025, we address several critical issues in radioimmunodetection and radioimmunotherapy, including the optimal antibody doses, the desirable antibody form for cancer detection, the optimal combinations of antibody forms and radionuclides for cancer treatment and the effectiveness of the modality. METHODS: Under the baseline conditions of a standard 70-kg man with a 20-g tumor embedded in the liver, the model was used to: (a) estimate absorbed doses in tumor and normal tissues, (b) determine dose-dependent antibody uptake in the tumor, (c) simulate tumor-to-background antibody concentration ratio and (d) calculate therapeutic ratios for different antibody forms and radionuclides. Sensitivity analysis further enabled us to determine antibody delivery barriers and to assess the modality under average and favorable tumor physiological conditions. RESULTS: By using ZCE025 under the baseline conditions, the model found that Fab was the most suitable form for cancer diagnosis, while 131l combined with F(ab')2 provided the highest tumor-to-bone marrow therapeutic ratio for cancer treatment. Sensitivity analysis showed that antibody permeability was the major barrier for antibody accretion in tumors. It also demonstrated that normal tissue antigen expression at a level lower than in the tumor had little effect on the therapeutic ratio. CONCLUSION: The model demonstrates that: (a) for radioimmunodetection, the most effective antibody form (Fab for ZCE025) was the lower mol weight form, yet not sensitive enough for hepatic metastasis detection; and (b) for radioimmunotherapy, a relatively fast-clearing antibody form (F(ab')2 for ZCE025) in combination with long half-life beta(-)-emitters was optimal, yet inadequate as the sole therapeutic modality for solid tumors.

Animals↗
PubMed1994

Pharmacoeconomic analysis of cefmenoxime dual individualization in the treatment of nosocomial pneumonia.

OBJECTIVE: To determine if dual individualization of cefmenoxime dosing is cost-effective. DESIGN: Retrospective, pharmacoeconomic decision analysis of two consecutively conducted prospective clinical studies. PATIENTS: Patients with documented gram-negative nosocomial pneumonia were evaluated. Thirty-three patients received cefmenoxime at standard dosing and 28 patients received doses according to dual individualization methodology. MAIN OUTCOME MEASURE: Antibiotic and infection-related costs were compared between groups. The number of hospital antibiotic days and costs incurred on those days were also evaluated. A decision model was constructed to characterize differences in treatment outcome. Probabilities within the decision tree were derived from 61 evaluable patients. Cost-effectiveness and incremental cost-effectiveness ratios were calculated. Sensitivity analysis was performed by varying outcome probabilities, antibiotic prices, and hospital room costs. RESULTS: Antibiotic and infection-related costs (mean +/- SEM) were $848 +/- 78 for standard cefmenoxime dosing and $1123 +/- 128 for dual individualization (p < 0.05). Total hospital costs were $10,660 +/- 1432 for standard dosing and $11,709 +/- 1900 for dual individualization (p > 0.05). Median antibiotic length of stay (ALOS) was 15.2 and 12.7 days for standard and dual individualization methodologies, respectively (p > 0.05). Incremental analysis of cost-effectiveness indicated that a similar reduction in length of stay for 259 dual individualization patients would save $321,808 annually. CONCLUSIONS: Sensitivity analysis indicates that, by reducing ALOS, dual individualization could be a cost-effective method of beta-lactam dosing for patients with pneumonia. A prospective study should be conducted to validate these findings.

Cefmenoxime↗
PubMed2006

EMLA and amethocaine for reduction of children's pain associated with needle insertion.

BACKGROUND: Children often experience pain from needle insertion procedures; therefore, several topical anaesthetics have been developed. OBJECTIVES: To compare the topical anaesthetics amethocaine and an eutectic mixture of local anaesthetics (EMLA) in terms of anaesthetic efficacy, ease of needle insertion and adverse events when used for intravenous cannulation and venipuncture in children. SEARCH STRATEGY: An exhaustive search that included over 30 databases and handsearching reference lists and journals. Language restrictions were not imposed. SELECTION CRITERIA: Randomized controlled trials were selected that compared EMLA and amethocaine for relieving children's pain from intravenous cannulation or venipuncture. DATA COLLECTION AND ANALYSIS: Two review authors independently determined eligibility for inclusion by assessing trial quality. Details of eligible studies were summarized. One author was contacted for additional information. Information about adverse events was obtained from the text of the trial reports. Review Manager 4.2 was used to perform a meta-analysis and compute relative risks (RR) with 95% confidence intervals. MAIN RESULTS: Six trials consisting of 534 children, three months to 15 years of age, were included in this review. A meta-analysis was done comparing amethocaine with EMLA on anaesthetic efficacy, ease of needle procedure and resultant skin changes. For anaesthetic efficacy, amethocaine significantly reduced the risk of pain compared to EMLA when all pain data were combined into a common pain metric (RR 0.78, 95% CI 0.62 to 0.98); when pain was self-reported by children (RR 0.63, 95% CI 0.45 to 0.87); or when pain was observed by researchers (sensitivity analysis: RR 0.71, 95% CI 0.52 to 0.96). Compared to EMLA, amethocaine significantly reduced the risk of pain when drugs were applied for the following durations: for 30 to 60 minutes (RR 0.61, 95% CI 0.41 to 0.91); when applied according to manufacturer's instructions (sensitivity analysis: RR 0.64, 95% CI 0.46 to 0.89); and when applied for over 60 minutes (RR 0.70, 95% CI 0.51 to 0.96). Amethocaine was also significantly more efficacious than EMLA when used specifically for intravenous cannulation (RR 0.70, 95% CI 0.55 to 0.88). Insufficient data were available to compare anaesthetic efficacy for venipuncture.A comparison of amethocaine and EMLA for ease of a needle procedure was not significant; only one trial reported data that could be included. For skin changes, EMLA was favoured in the analysis of erythema (RR 14.83, 95% CI 2.28 to 96.36). Erythema was observed after use of amethocaine whereas blanching was observed after using EMLA. Adverse effects included itching and one case of conjunctival irritation. AUTHORS' CONCLUSIONS: Although EMLA is an effective topical anaesthetic for children, amethocaine is superior in preventing pain associated with needle procedures.

Adolescent↗
PubMedDate not supplied

Long-term treatment costs associated with implant-supported mandibular prostheses in edentulous patients.

PURPOSE: The study's aim was to report long-term costs in edentulous patients treated with mandibular implant-supported prostheses. MATERIALS AND METHODS: Ninety patients were divided into four groups based on the type of implant prosthesis (fixed or overdenture) and treatment year. Records were obtained from dental charts, and an economic analysis from the patient's perspective was conducted. Clinical time associated with various procedures was measured and applied to the four groups. Salary rates by age, occupation, and gender were used to value patients' time. Direct clinical and time costs over 10 years were converted to 2002 Canadian dollars using the Consumer Price Index and discounted at a 3% rate. A sensitivity analysis at an equal salary rate was carried out to test the robustness of the time costs. RESULTS: Initial treatment and maintenance costs over the observation period were significantly higher for fixed compared to overdenture prostheses. A significant improvement in maintenance costs for the first patient group treated with fixed prostheses was observed over the follow-up period. Longer term (15 years) treatment costs for the initial two groups were significantly higher for the fixed group. The sensitivity analysis at an equal salary rate demonstrated the same trend: Time costs were significantly higher for the fixed groups. CONCLUSION: Long-term treatment costs indicated that the mandibular overdenture was a less expensive treatment compared to the fixed implant prosthesis.

Age Factors↗
PubMed2006

Preoperative use of mupirocin for the prevention of healthcare-associated Staphylococcus aureus infections: a cost-effectiveness analysis.

OBJECTIVE: Staphylococcus aureus is the most common cause of healthcare-associated infections. Intranasal mupirocin treatment probably decreases S. aureus infections among colonized surgical patients. Using cost-effectiveness analysis, we evaluated the cost-effectiveness of preoperative use of mupirocin for the prevention of healthcare-associated S. aureus infections. METHODS: Three strategies were compared: (1) screen with nasal culture and give treatment to carriers, (2) give treatment to all patients without screening, and (3) neither screen nor treat. A societal perspective was taken. Adverse outcomes included bloodstream infection, pneumonia, surgical site infection, death due to underlying illness or infection, readmission, and the need for home health care. Data inputs were obtained from an extensive MEDLINE review and from publicly available government data sources. The following base-case data inputs (and ranges) for sensitivity analysis were used: rate of S. aureus carriage, 23.1% (19%-55%); efficacy of mupirocin treatment, 51% (8%-75%); mupirocin treatment cost, 48.36 US Dollars (24.18-57.74 US Dollars); and hospital costs of bloodstream infection, 25,128 US Dollars (6,194-40,211 US Dollars), pneumonia, 18,366 US Dollars (5,574-28,952 US Dollars), and surgical site infection 16,256 US Dollars (5,119-22,553 US Dollars). Widespread use of mupirocin has been associated with high levels of mupirocin resistance; therefore, a broad range of estimates for efficacy was tested in the sensitivity analysis. PATIENTS: The target population included patients undergoing nonemergent surgery requiring postoperative hospitalization. RESULTS: Both the screen-and-treat and treat-all strategies were cost saving, saving 102 US Dollars per patient screened and 88 US Dollars per patient treated, respectively. In 1-way sensitivity analyses, the model was robust with respect to all data inputs except for the efficacy of mupirocin treatment. If the efficacy is less than 16.1%, then the screen-and-treat strategy is cost incurring. A treat-all strategy was more cost saving if the rate of S. aureus carriage was greater than 42.7%, the mupirocin cost was less than 29.87 US Dollars, or nursing compensation was greater than 64.21 US Dollars per hour. CONCLUSION: Administration of mupirocin before surgery is cost saving, primarily because healthcare-associated infections are very expensive. The level of mupirocin efficacy is critical to the cost-effectiveness of this intervention.

Anti-Bacterial Agents↗
PubMedDate not supplied

Cost-effectiveness analysis of a rural/urban first-responder defibrillation program.

OBJECTIVE: To analyze the cost-effectiveness of a proposed first-responder defibrillation program in a small rural area in comparison with a recently initiated first-responder program in an adjoining urban center in southwestern Ontario. The purpose of the analysis was to quantify the expected benefits of the proposed program to determine whether the costs are justified. METHODS: This analysis was conducted on the city of Waterloo (population 80,000 over 25 square miles) and the adjoining rural township of Wellesley (population 8,000 over 105 square miles). The township has volunteer fire department first responders with basic life support (BLS), and basic life support/defibrillation (BLS-D) ambulances as the second tier; whereas the city's full-time fire department has recently adopted a first-responder defibrillation (BLS-D) program backed up by the same BLS-D ambulance service. The most relevant costs identified were the capital costs of the defibrillators, ancillary equipment, and biomedical service for preventive maintenance and routine nonwarranty work. Response intervals and percentage of patients found in ventricular fibrillation were projected and sensitivity analysis was applied. RESULTS: The projected cost per life saved is $6,776 (C) in the urban area and $49,274 (C) in the rural area using an incremental save rate of 6%. Applying sensitivity analysis to the data, the save rate varied from 2% to 10%, resulting in a cost per life saved of $20,328 (C) and $4,066 (C), respectively, in the urban community. For the rural area, the cost per life saved ranged from $147,821 (C) (2%) to $29,564 (C) (10%). Even the worst-case save rate for the urban center [2%; $20,328 (C)] is significantly less than the best-case save rate [10%; $29,564 (C)] for the rural area. CONCLUSIONS: The cost per life saved for a rural first-responder defibrillation program is significantly more expensive than one for an urban center. However, the cost per life saved is still economical compared with common treatments for other life-threatening illnesses.

Cost-Benefit Analysis↗
PubMedDate not supplied

Concomitant radiochemotherapy in unresectable carcinoma of the exocrine pancreas: cost-effectiveness analysis.

One of the principal therapeutic options in unresectable carcinoma of exocrine pancreas is concomitant radiochemotherapy. However, in current scientific literature cost analyses of this therapeutic modality are lacking. A payer-oriented cost-effectiveness analysis of concomitant radiochemotherapy was carried out. Outcomes and differences in costs relatively to two different therapeutic strategies were compared retrospectively: biliary drainage + observation (group 1); biliary drainage + concomitant radiochemotherapy (group 2). Cost-effectiveness was assessed based on the analysis of incremental cost of benefit in terms of survival in group 2. As incremental cost of group 2 was considered that of radiochemotherapy, costs of diagnosis and staging being similar in the two groups. The unit of measurement used was $/Lys (LYS = years of life saved). For estimates of cost-effectiveness in different clinical situations, a sensitivity analysis was carried out. The incremental cost of standard concomitant radiochemotherapy was shown to be $4,755. Incremental costs relatively to the situations of minimum and maximum treatment were shown to be $4,410 and $8,375, respectively. Median survival was 4.5 and 10 months in group 1 and 2 respectively (logrank: p = 0.0046). The benefit in terms of survival achieved by concomitant radiochemotherapy was shown to be 5.5 months equal to 0.46 years. Therefore, in the standard situation, the treatment cost-effectiveness can be estimated in: $4,755/0.46 years = $10,337/LYS, that is, the cost of a year of life saved was shown to be $10,337. Results of sensitivity analysis showed that cost-effectiveness can be estimated in the range $7,603 and $25,379/LYS. In conclusion, concomitant radiochemotherapy in patients with unresectable pancreatic carcinoma is able to improve the quality of life through the relief of related symptoms as well as median survival (10 vs 4.5 months). Costs of these benefits, even if considering better survival only, based on this analysis, were shown to be acceptable.

Adult↗
PubMed2006

Benefit of taxanes as adjuvant chemotherapy for early breast cancer: pooled analysis of 15,500 patients.

BACKGROUND: The magnitude of the survival benefit of taxanes as adjuvant chemotherapy for early breast cancer is still unclear. A pooled analysis of Phase III trials was performed to assess the advantages that adjuvant taxane chemotherapy has over standard chemotherapy. METHODS: All Phase III trials were considered eligible. A pooled analysis was accomplished and event-based relative risk ratios (RR) with 95% confidence intervals (95% CI) were derived. The significant differences in disease-free survival (DFS) and overall survival (OS) were explored. Magnitude outcome measures were absolute benefits and the number of patients needed to treat. A heterogeneity test was applied as well. A sensitivity analysis in 6 subpopulations was also performed. RESULTS: Nine trials designed to assess if paclitaxel or docetaxel improve survival (15,598 patients) were gathered. One of the 9 trials did not report OS results. Significant differences in favor of taxanes were seen in DFS in the overall (RR: 0.86; 95% CI, 0.81-0.90 [P<.00001]) and lymph node-positive population (RR: 0.84; 95% CI, 0.79-0.89 [P<.0001]), and in OS in the overall (RR: 0.87; 95% CI, 0.81-0.83 [P<.0001]) and lymph node-positive population (RR: 0.84; 95% CI, 0.77-0.92 [P<.0001]). The absolute benefits in DFS and OS in favor of taxanes ranged from 3.3% to 4.6% and from 2.0% to 2.8%, respectively. CONCLUSIONS: Considering all the available Phase III trials, taxane-based adjuvant chemotherapy for early breast cancer seems to add a significant benefit in both DFS and OS over standard chemotherapy. The lack of significant heterogeneity in the sensitivity analysis underscores the homogeneous effect across all trials.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Comparison of open versus bedside percutaneous dilatational tracheostomy in the cardiothoracic surgical patient: outcomes and financial analysis.

BACKGROUND: The clinical and financial outcomes of a change in practice from traditional tracheostomy (open) to bedside percutaneous dilatational tracheostomies (PDT) was evaluated in patients who underwent cardiothoracic surgery. METHODS: During 3 years, 86 tracheostomies were performed in more than 4,000 patients who underwent cardiac surgery, 59 open and 27 PDT. A retrospective analysis was performed comparing clinical and financial outcomes of the two groups. RESULTS: There were no significant differences in demographics, medical histories, operations, or complications between open and PDT except the open group experienced more postoperative arrhythmias (70% [41 of 59] versus 44% [12 of 27], p < 0.05). Total savings associated with 1 year of PDT was $84,000, for a projected discounted savings of $283,000 during the study period. A sensitivity analysis of critical economic variables (number of tracheostomies per year, cost of operating room per minute, cost of intensive care unit bed per day) was included to evaluate the impact on cost savings. The net present value analysis, which discounts future savings by an appropriate interest rate, yielded a range of projected savings of PDT more than 5 years of $73,000 to $541,000 with a best estimate of $304,000 using figures established from our 3-year experience with PDT. Sensitivity analysis of the net present value for each critical variable was $227,000 per day of reduced intensive care unit length of stay, $180,000 per cost of operating room avoidance, $100,000 per intensive care unit bed cost per day, and $11,000 per additional tracheostomy per year. CONCLUSIONS: There were no significant clinical differences between open and PDT in cardiac surgery patients during the 3-year study period; however, PDT offered significant cost savings.

Cardiac Surgical Procedures↗
PubMed2004

Decision analysis of the cost-effectiveness of repetitive transcranial magnetic stimulation versus electroconvulsive therapy for treatment of nonpsychotic severe depression.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a new treatment with promise for resistant depression. OBJECTIVE: We tested the economic feasibility of this new method compared with electroconvulsive therapy (ECT). METHOD: An economic decision analysis was used to compare the costs of three different treatment strategies for nonpsychotic severe depression. The strategies were: ECT alone; rTMS alone; and rTMS followed by ECT for nonresponders (rTMS-to-ECT). We calculated 12-month costs and quality adjusted life years (QALYs) for the three treatment options for all nonpsychotic, severely depressed United States patients who would have otherwise undergone ECT. A sensitivity analysis was performed to test the degree of change in outcome with various parameter changes. RESULTS: The additional cost of using ECT alone compared with rTMS alone was 460,031 US dollars per quality adjusted year of life gained. For ECT versus rTMS-to-ECT, there was both an increased cost and a loss of 1,538 QALYs with ECT alone. The sensitivity analysis revealed the model to be robust with various parameter changes. CONCLUSION: If rTMS were to be made widely available clinically in the US, it would offer a substantial economic benefit over ECT in treating resistant depression. Using rTMS-to-ECT offers not only an economic advantage but also an increase in QALYs. This analysis suggests that rTMS would be a cost-effective treatment for depression compared with the current option of ECT alone.

Cost-Benefit Analysis↗
PubMed2005

Effect of uncertainty about population parameters on pharmacodynamics-based prediction of clinical trial power.

Clinical trial simulation (CTS) may be applied to predict power of intended drug trials on the basis of pharmacokinetic/pharmacodynamic (PKPD) drug models. The validity of such predictions will, among other factors, depend on the degree of uncertainty about population parameters entering the simulation. In the current article, we illustrate how population parameter uncertainty may be incorporated in the overall simulation model, using a worked example to demonstrate our approach. Moreover, we suggest an ANOVA-based method for sensitivity analysis, aimed at distinguishing important population parameters, required to be input in the model with a low degree of uncertainty for precise power predictions, from unimportant parameters, which may be entered with a high degree of uncertainty without affecting the reliability of predictions. Our results from simulations with different settings of hyperparameters and doses suggest that indices derived from this type of sensitivity analysis may be used for grading the influence on prediction quality of uncertainty about different population parameters and, thus, facilitate the allocation of resources expended for the preparation of a successful CTS project.

Computer Simulation↗
PubMed2004

[Comparison of the cost-effectiveness of the most common diagnostic methods for coronary artery disease].

BACKGROUND AND OBJECTIVE: The cost-effectiveness of medical procedures is becoming a crucial factor besides their efficacy in clinical decision-making. We performed a cost-effectiveness analysis of the most common diagnostic modalities used in assessing coronary artery disease (CAD). METHODS: A decision tree model for determining the cost-effectiveness in CAD diagnosis was applied to the situation in Germany to calculate the cost-effectiveness of exercise ECG (ExECG), stress echocardiography (ECHO), myocardial scintigraphy (SPECT), and coronary angiography (ANGIO). The cost-effectiveness was defined as direct and induced costs per correctly identified patient. A sensitivity analysis was performed varying the predictive accuracies, the complication-related costs, and costs and complication rates of ANGIO. RESULTS: The costs per correctly identified patient decreased in a hyperbolic fashion as the pretest likelihood of CAD increased due to the higher incidence of positive findings. For a pretest likelihood between 10 and 40%, ExECG and ECHO were most cost effective with costs per CAD patient of 5,880 - 2,500 EUR and 6,410 - 2,280 EUR, respectively. The combination of ExECG und ECHO (application of the second modality in case the first one was nondiagnostic) further improved the cost-effectiveness up to a pretest likelihood of 35%. For a pretest likelihood of 50% or greater, ANGIO costing 1,880 - 940 EUR per correct diagnosis was most cost-effective. Sensitivity analysis revealed no significant changes demonstrating the robustness of the model. CONCLUSION: ANGIO is the most cost-effective procedure for a pretest likelihood of 50% or greater. At lower pretest likelihoods, ExECG, ECHO and the combined ExECG/ECHO strategy based on economic considerations are the preferred modalities for diagnosis of CAD.

Cohort Studies↗
PubMed2004

Cost-effectiveness of hip protectors in the prevention of osteoporosis related hip fractures in elderly nursing home residents.

OBJECTIVE: Hip fracture is a common complication of osteoporosis, resulting in significant morbidity and mortality, with a high financial cost to the healthcare system. Hip protectors have been advocated as an effective method to prevent hip fractures in high-risk individuals. This study models the cost-effectiveness of hip protectors in the prevention of osteoporosis related hip fractures in elderly nursing home residents. METHODS: An incremental cost-effectiveness analysis was performed comparing hip protectors to "no treatment" and to "calcium and vitamin D supplements." The study population was a hypothetical cohort of 1000 nursing home residents. A societal perspective, with a lifetime time horizon, was adopted. Data regarding costs, effectiveness, and quality of life measures were collected from the current literature and from Peace Arch Hospital, a community hospital in White Rock, British Columbia, Canada. Sensitivity analysis was performed. RESULTS: Hip protector use was found to be a dominant strategy compared to no treatment and to calcium and vitamin D supplements. Dominance implies lower cost and higher effect, generating cost-effectiveness ratios less than zero. Dominance with respect to cost and effectiveness of hip protectors in preventing hip fractures persisted when the model was subjected to probabilistic sensitivity analysis. CONCLUSION: Cost-effectiveness analysis suggests that hip protectors could save money while preventing hip fractures and improving quality of life in nursing home residents.

Aged↗
PubMed1991

Formulary evaluation of second-generation cephamycin derivatives using decision analysis.

Use of decision analysis in the formulary evaluation of the second-generation cephamycin derivatives cefoxitin, cefotetan, and cefmetazole is described. The rating system used was adapted from one used for the third-generation cephalosporins. Data on spectrum of activity, pharmacokinetics, adverse reactions, cost, and stability were taken from the published literature and the FDA-approved product labeling. The weighting scheme used for the third-generation cephalosporins was altered somewhat to reflect the more important aspects of the cephamycin derivatives and their potential role in surgical prophylaxis. Sensitivity analysis was done to assess the variability of the final scores when the assigned weights were varied within a reasonable range. Scores for cefmetazole and cefotetan were similar and did not differ significantly after sensitivity analysis. Cefoxitin scored significantly lower than the other two drugs. In the absence of data suggesting that the N-methyl thiotetrazole side chains of cefmetazole and cefotetan cause substantial toxicity, these two drugs can be considered the most cost-efficient members of the second-generation cephamycins.

Bacterial Infections↗