Biomedical subjects

Sean D Sullivan

Publications and source records attributed to Sean D Sullivan.

At least 55 records · Page 3Linked to original sources

PubMed2003

Development and validation of a grading system for the quality of cost-effectiveness studies.

PURPOSE: To provide a practical quantitative tool for appraising the quality of cost-effectiveness (CE) studies. METHODS: A committee comprising [corrected] of health economists selected a set of criteria for the instrument from an item pool. Data collected with a conjoint analysis survey on 120 international health economists were used to estimate weights for each criterion with a random effects regression model. To validate the grading system, a survey was sent to 60 individuals with health economics expertise. Participants first rated the quality of three CE studies on a visual analogue scale, and then evaluated each study using the grading system. Spearman rho and Wilcoxon tests were used to detect convergent validity and analysis of covariance (ANCOVA) for discriminant validity. Agreement between the global rating by experts and the grading system was also examined. RESULTS: Sixteen criteria were selected. Their coefficient estimates ranged from 1.2 to 8.9, with a sum of 93.5 on a 100-point scale. The only insignificant criterion was "use of subgroup analyses." Both convergent validity and discriminant validity of the grading system were shown by the results of the Spearman rho (correlation coefficient = 0.78, P < 0.0001), Wilcoxon test (P = 0.53), and ANCOVA (F(3,146) = 5.97, p = 0.001). The grading system had good agreement with global rating by experts. CONCLUSIONS: The instrument appears to be simple, internally consistent, and valid for measuring the perceived quality of CE studies. Applicability for use in clinical and resource allocation decision-making deserves further study.

Cost-Benefit Analysis↗

PubMed2003

Conventional radiography, rapid MR imaging, and conventional MR imaging for low back pain: activity-based costs and reimbursement.

PURPOSE: To incorporate personnel and equipment use time in an activity-based cost comparison of conventional radiography and conventional and rapid magnetic resonance (MR) imaging for low back pain (LBP). MATERIALS AND METHODS: At each of four Seattle Lumbar Imaging Project (SLIP) sites, patients were randomized to undergo conventional radiography or rapid MR imaging of the lumbar spine. For sample SLIP patients and for similar non-SLIP patients undergoing conventional lumbar spine MR imaging as usual care in calendar year 2000, measured imaging room use and technologist and radiologist times were multiplied by costs per minute of standard equipment acquisition, personnel compensation, and related expenses. Resulting provider-perspective costs and Seattle area Medicare reimbursements for conventional MR imaging and radiography for calendar year 2001 were used to estimate future "normative" reimbursement for rapid MR imaging. RESULTS: For 23 conventional radiography, 27 rapid MR imaging, and 38 conventional MR imaging examinations timed in calendar year 2000, all rapid MR imaging times exceeded those of conventional radiography but were less than those of conventional MR imaging. All 0.3- and 0.35-T MR imaging room and technologist times exceeded those for 1.5-T MR imaging. Average costs (in 2001 dollars) were $44 for conventional radiography, 126 US dollars for 1.5-T rapid MR imaging, 128 US dollars for 0.3-0.35-T rapid MR imaging, 267 US dollars for 1.5-T conventional MR imaging, and 264 US dollars for 0.3-0.35-T conventional MR imaging. Conclusions regarding cost differences between conventional radiography and rapid MR imaging were robust to plausible parameter value changes evaluated in sensitivity analyses. Conventional radiography reimbursement was 44 US dollars. Applying the ratio of reimbursement (620 US dollars) to costs (264-267 US dollars) for conventional MR imaging to rapid MR imaging costs predicted reimbursement of 292-300 US dollars for the new modality. CONCLUSION: Times and costs for rapid MR imaging are roughly three times those for conventional radiography but about half those for conventional MR imaging for LBP. While current conventional radiography costs exceed reimbursement, current conventional MR and projected rapid MR imaging reimbursements exceed costs.

Cost-Benefit Analysis↗

PubMed2003

The economics of venous thromboembolism prophylaxis: a primer for clinicians.

Cost-effectiveness information can help health-system participants make decisions about diagnostic or therapeutic innovations that are more expensive but incrementally safe and effective. However, these analyses cannot help decide whether a less expensive approach is "sufficient" and funds ought to be allocated to other medical issues entirely. At present, formulary committees are commonly determining that medications are "mostly equivalent" in efficacy and safety and choosing individual medications or classes of medications based on cost. Clinicians may not agree with these decisions and will need to understand their rationale. For prophylaxis of venous thromboembolism after hip and knee replacement and hip fracture surgery, many preventive modalities are available with different safety and efficacy profiles and different costs. It is possible to list the important safety and efficacy outcomes of prophylaxis, estimate their incidences and costs, and "model" comparisons of one modality vs another, in order to help decide whether one is preferable.

Anticoagulants↗

PubMed2003

Measuring the outcomes and pharmacoeconomic consequences of venous thromboembolism prophylaxis in major orthopaedic surgery.

Patients who have undergone orthopaedic surgery represent a high-risk group for venous thromboembolism (VTE). Despite the routine prophylactic use of antithrombotic agents, patients still experience thrombotic events that can result in mortality and acute morbidity and, in significant numbers of patients, may lead to long-term consequences such as the post-thrombotic syndrome. Increasingly, initial VTE events occur after hospital discharge since the length of stay in hospital after major orthopaedic surgery has decreased in many countries. There is a need for further improvement in the prevention of VTE. As well as undergoing extensive safety and efficacy studies for registration purposes, new prophylactic strategies need to be evaluated from a pharmacoeconomic perspective to help guide their introduction into routine clinical practice. Over the past 15 years a number of pharmacoeconomic evaluation studies of VTE prophylaxis have been carried out in orthopaedic patients, most of which evaluated short-term clinical endpoints. During the same period, improvements in our understanding of the natural history of VTE as well as the emergence of new treatments have led to changes in the management of patients with, or at risk of, VTE. The aim of this paper was to address how best to conduct pharmacoeconomic analyses of new antithrombotic agents in light of changes in practice patterns for orthopaedic patients and greater understanding of the disease process. We put forward recommendations for relevant outcome measures, timeframes, endpoints and epidemiologic data sources. We also suggest a structure for a pharmacoeconomic model. In this model, the outcomes and costs of VTE-related care during both the acute and chronic phases of the disease are incorporated. Symptomatic deep vein thrombosis and pulmonary embolism, recurrent VTE, post-thrombotic syndrome, major hemorrhage and all-cause death are included. We also recommend that the relevance of quality-adjusted survival is investigated, and that economic appraisals are presented in both cost-consequence and budget-impact approaches. These recommendations are based on extensive examination of recent advances in the management of VTE combined with a greater understanding of its natural history.

Anticoagulants↗

PubMed2002

The practicality and validity of directly elicited and SF-36 derived health state preferences in patients with low back pain.

Recent research has derived preference scores from the SF-36. We compare the practicality and construct validity of SF-36 derived preference scores with directly elicited time trade off (TTO) and visual analogue scale (VAS) scores. In this observational study, low back pain (LBP), patients were asked to complete disease specific, generic (SF-36), and health state preference (VAS and TTO) instruments. Baseline SF-36 responses were converted to preference scores using six published algorithms. Response rates for the SF-36 derived and TTO preference values were 354 of 379 (93%) and 303 of 379 (80%), respectively. Thirty patients were excluded from the TTO exercise because of difficulties comprehending the scaling task. Choice based methods (standard gamble, TTO) yielded higher and more uniform estimates of preference (0.77-0.79) than non-choice based methods (VAS) (0.42-0.70). Directly elicited TTO values were variable and had less power to distinguish among patients with differing severity of LBP. All SF-36 derived preferences exhibited a minimum threshold implying a potential floor effect for severely ill patients. SF-36 derived preferences demonstrated good practicality and construct validity in this setting, however different methods will yield disparate estimates of marginal benefit. This emphasises the need for a standardised algorithm for deriving SF-36 preference scores.

Algorithms↗

PubMed2002

The cost-effectiveness of an inner-city asthma intervention for children.

BACKGROUND: Comprehensive management efforts to reduce asthma morbidity among children in urban areas with high levels of poverty and large minority populations have been inconclusive. The National Cooperative Inner-City Asthma Study (NCICAS) demonstrated improved symptom outcomes but did not evaluate cost-effectiveness in this population. OBJECTIVE: We sought to examine the incremental cost-effectiveness of a comprehensive social worker-based education program and environmental control in children with asthma stratified by baseline level of asthma control. METHODS: We performed a prospective cost-effectiveness analysis alongside a randomized trial. A total of 1033 children and their families residing in 8 inner-city urban areas in the United States were enrolled in the NCICAS. Outcomes included symptom-free days, cost per symptom-free day gained, and annual costs of asthma morbidity compared by baseline symptom control, previous hospitalization, and previous unscheduled physician visits. RESULTS: The NCICAS intervention significantly reduced asthma symptoms. First-year intervention costs were 245 US dollars higher for the intervention children compared with those receiving usual care. There were no additional intervention-related costs during the second year. When compared with usual care, the intervention improved outcomes at an average additional cost of 9.20 US dollars per symptom-free day gained (95% CI, -12.56 to 55.29 US dollars). The intervention was cost saving in 3 strata of children with increasing asthma severity. CONCLUSIONS: A multifaceted asthma intervention program reduced symptom days and was cost-effective for inner-city children with asthma. In children with more severe disease, the intervention was substantially more effective and reduced costs compared with that seen in control children. Organizations serving this population should consider this strategy as part of a comprehensive disease-management program for asthma.

Asthma↗

PubMed2002

Health care utilization and cost among adults with chronic rhinosinusitis enrolled in a health maintenance organization.

OBJECTIVE: Our goal was to measure the impact of chronic rhinosinusitis (CRS) on the use and cost of health care by adults in a health maintenance organization (HMO). SETTING AND SUBJECTS: In the setting of the Group Health Cooperative, an HMO in Washington State, we conducted a study of all 218,587 adults (>/=18 years) who used services during 1994. Using automated data, 20,175 adults were identified with one or more CRS diagnoses during 1994. OUTCOME MEASURES: We identified nonurgent outpatient visits, pharmacy fills, urgent visits, hospital days, and their associated costs (per adult per year). RESULTS: The marginal utilization associated with a diagnosis of CRS was 2.0 nonurgent outpatient visits, 5.1 pharmacy fills, 0.01 urgent visit, and -0.07 hospital day. The marginal total cost of CRS was $206. CONCLUSIONS: Adults with CRS had higher costs primarily because of increased nonurgent outpatient visit and pharmacy fill utilization. The overall direct cost of CRS in the United States in 1994 is estimated to have been $4.3 billion.

Adolescent↗

PubMed2002

Effectiveness of screening examinations to detect unrecognized exercise-induced bronchoconstriction.

OBJECTIVE: To determine if a physician-administered physical examination and screening questionnaire accurately detects exercise-induced bronchoconstriction (EIB) in adolescent athletes. STUDY DESIGN: Cross-sectional study of 256 adolescents participating in organized sports from 3 suburban high schools. The number of persons screened positive for EIB by physical examination and questionnaire was compared with the number of persons with EIB diagnosed by a "gold standard" test that consisted of a 7-minute exercise challenge followed by serial spirometry. RESULTS: We diagnosed EIB in 9.4% of adolescent athletes. The screening history identified persons with symptoms or a previous diagnosis suggestive of EIB in 39.5% of the participants, but only 12.9% of these persons actually had EIB. Among adolescents with a negative review of symptoms of asthma or EIB, 7.8% had EIB. Among adolescents with no previous diagnosis of asthma, allergic rhinitis, or EIB, 7.2% had EIB diagnosed by exercise challenge. Persons who screened negative on all questions about symptoms or history of asthma, EIB, and allergic rhinitis accounted for 45.8% of the adolescents with EIB. CONCLUSIONS: EIB occurs frequently in adolescent athletes, and screening by physical examination and medical history does not accurately detect it.

Adolescent↗

PubMed2002

Economic issues and antibiotic resistance in the community.

BACKGROUND: Inappropriate antibiotic use is generally considered to be the primary cause of antibiotic resistance in the community. Multiple economic factors, at the level of physicians, patients, healthcare organizations, and pharmaceutical companies, foster poor antibiotic use. OBJECTIVE: To describe the influence of economic factors on the use and development of antibiotics and to evaluate the extent to which the cost of resistance is important in the economic evaluation of antibiotic products. DATA SOURCES: Literature identified through MEDLINE (1966-May 2001), bibliographies from relevant articles, government reports, and proceedings from conferences about antibiotic resistance. DATA SYNTHESIS: Economic factors at all levels of the healthcare system contribute to the inappropriate use of antibiotics in the community setting. Relatively little economic research has been published on antibiotic resistance, and very few cost-effectiveness analyses of antibiotic treatment alternatives have explicitly included the cost of resistance. CONCLUSIONS: A better understanding of economic factors that influence the prescribing, marketing, and development of antibiotics could lead to more successful efforts at curtailing the growth of antibiotic resistance in the community setting.

Animals↗

PubMed2002

Collaborative care model to improve outcomes in major depression.

OBJECTIVE: To develop a pharmacist intervention to improve depression care and outcomes within a primary care setting. METHODS: Pragmatic, randomized trial of a clinical pharmacist collaborative care intervention versus usual care in a busy, academic family practice clinic. RESULTS: Seventy-four patients diagnosed with a new episode of major depression and started on antidepressant medications were randomized to enhanced care (EC) or usual care (UC) groups. EC consists of a clinical pharmacist collaborating with primary care providers (PCPs) to facilitate education, initiation, and titration of acute-phase antidepressant treatment to monitor treatment adherence and to prevent relapse. Control patients receive UC by their PCP. The main end point is reduction of depression symptoms over time as measured by the Hopkins Symptom Checklist (SCL-20). Other outcomes include the Diagnostic and Statistical Manual of Mental Disorders, (DSM-IV) criteria for major depression, health-related quality of life measured by the Medical Outcomes Study Short Form 12 (SF-12), medication adherence, patient satisfaction, and healthcare utilization. The main end point and the cost of treating major depression will be used to estimate the cost-effectiveness of the collaborative care model. CONCLUSIONS: The study is a unique, ongoing trial that may have important implications for the treatment of depression in primary care settings as well as new roles for clinical pharmacists.

Adult↗

PubMed2002

Lipid-lowering drug use and cardiovascular events after myocardial infarction.

BACKGROUND: The benefits of lipid-lowering drug treatment for the secondary prevention of coronary heart disease have been well established by randomized, controlled trials. Nonetheless, the risk of events has not been compared directly for inhibitors of hydroxymethylglutaryl coenzyme A reductase (statins) and non-statin lipid-lowering drugs. Further, it remains uncertain whether patients in usual practice who are treated with lipid-lowering drugs after myocardial infarction (MI) gain a similar benefit with regard to the risk of cardiovascular events compared with patients in randomized, controlled trials. OBJECTIVE: To assess the association between lipid-lowering drug therapies in usual clinical practice and the risk of cardiovascular events in patients with a first MI who were discharged alive from the hospital. METHODS: An inception-cohort study was performed among 1956 enrollees of Group Health Cooperative who sustained an incident MI between July 1986 and December 1996 and survived for at least 6 months after hospitalization. Subjects with untreated low-density-lipoprotein cholesterol concentrations > 130 mg/dL or untreated total cholesterol concentrations >200 mg/dL were included. The median duration of follow-up after the first MI was 3.3 years. Medical record review was used to collect information on cardiovascular risk factors. Computerized pharmacy records were used to assess antihyperlipidemic drug use during the first 6 months after hospitalization. RESULTS: Compared with 1263 subjects who did not receive lipid-lowering drug treatment, 373 subjects who received statins had a lower risk of recurrent coronary events (relative risk [RR] 0.59; 95% CI 0.39 to 0.89), stroke (RR 0.82; 95% CI 0.35 to 1.95), atherosclerotic cardiovascular mortality (RR 0.49; 95% CI 0.21 to 1.13), and any atherosclerotic cardiovascular event (RR 0.63; 95% CI 0.40 to 0.98). Among 320 subjects who used non-statin drug therapies, the RRs were 0.66 (95% CI 0.45 to 0.97) for recurrent coronary events, 0.95 (95% CI 0.46 to 1.95) for stroke, 0.68 (95% CI 0.35 to 1.32) for cardiovascular mortality, and 0.77 (95% CI 0.53 to 1.11) for any atherosclerotic cardiovascular event, compared with untreated hyperlipidemic patients. CONCLUSIONS: In this study of MI survivors, the use of lipid-lowering drug therapies after hospitalization was associated with a reduced risk of cardiovascular events. These results emphasize the importance of lipid-lowering drug treatment in patients with hyperlipidemia who survive a first MI.

Cholesterol↗

PubMed2002

A guideline for the use of pharmacoeconomic models of diabetes treatment in the US managed-care environment.

BACKGROUND: The Academy of Managed Care Pharmacy has recently created guidelines for the submission of pharmacoeconomic models. Although these guidelines provide a general framework for the integration of pharmacoeconomic models in the drug selection process, a more disease-specific and practical 'hands-on' approach is needed for pharmacy staff and Pharmacy and Therapeutics (P&T) committee members. OBJECTIVE: To answer the question, 'How can pharmacoeconomic models comparing treatments for diabetes and its complications be evaluated and used to make more informed formulary decisions?' METHODS: We determined the information needs of a managed care organisation (MCO) making coverage decisions for diabetes therapies and reviewed current guidelines for the submission of pharmacoeconomic models to MCOs. We then developed a set of practical questions for evaluating models of diabetes treatment in a managed-care environment. RESULTS: Information needed by P&T committees in relation to new diabetes medications includes the long-term benefits of reduced micro- and macrovascular complications and changes in drug utilisation patterns, in addition to the immediate drug budget impact. Because diabetes is a complex disease, the peer-review process should be relied on as a first step to help ensure the validity of a model. Then, the end-user of a model should evaluate the sources of data to inform the model,the generalisability of the model for an MCO population, andthe face validity of the assumptions of the model. CONCLUSION: Pharmacoeconomic models in diabetes offer potential for assisting P&T committee members in making more informed decisions. The guidelines presented here provide a practical approach for model assessment. However, additional expertise will be needed by MCOs to appropriately evaluate these models, and joint educational programmes between managed care, academia, and industry should be considered as a mechanism for improving technology assessment in diabetes care.

Cost-Benefit Analysis↗

PubMed2002

Health state preference assessment in diabetic peripheral neuropathy.

OBJECTIVE: To assess patient preferences for health states associated with diabetic peripheral neuropathy (DPN). DESIGN AND INTERVENTION: Seven health states describing varying stages of disease severity in DPN were developed: mild neuropathy, painful neuropathy, severe neuropathy, minor ulcer, severe ulcer, minor amputation and major amputation. Using a computer interview, both rating scale (RS) and standard gamble (SG) preference scores were elicited from 52 patients with diabetes mellitus. SETTING: A US university medical centre and a Veterans Affairs clinic. STUDY PARTICIPANTS: Adult patients with type 1 and type 2 diabetes mellitus between the ages of 18 and 80 years. Patients were excluded if they had been diagnosed with DPN. RESULTS: Preference scores decreased in accordance with greater symptomatic and functional impairment. Median RS scores ranged from 0.89 to 0.23 for the seven health states. Median SG scores ranged from 0.96 to 0.65. CONCLUSIONS: Patient preferences for health states decrease as a function of increasing disease severity in DPN. The result is robust across the RS and SG methods of preference measurement. These results may be useful in informing policy analyses for resource allocation in patients with diabetes mellitus.

Adult↗

PubMedDate not supplied

The Academy of Managed Care Pharmacy Format for Formulary Submissions: an evolving standard--a Foundation for Managed Care Pharmacy Task Force report.

OBJECTIVE: The objective of this report is to provide, in detail, the evidentiary requirements contained in Version 2.0 of the Academy of Managed Care Pharmacy's (AMCP's) Format for Formulary Submissions and to elaborate on several key issues regarding the use of the Format that users, potential users, and pharmaceutical manufacturers have raised since AMCP published the first version of the guidelines in October 2000. BACKGROUND: The AMCP published its Format for Formulary Submissions in October 2000. The AMCP leadership and its members were motivated to develop these guidelines by a growing need to ensure that any increased utilization of medications, biopharmaceuticals, and vaccine products was appropriate and that newer products would bring added clinical and economic value to covered populations. Since publication of the Format, it has garnered nationwide publicity and attracted considerable positive and negative attention. As adoption of the AMCP Format has spread, manufacturers have begun to standardize the framework within which they present population-specific data. Since publication of the AMCP Format, the AMCP and the Foundation for Managed Care Pharmacy (FMCP) have continuously sought input from pharmaceutical manufacturers and health-system pharmacists through various venues to improve and clarify the process. Version 2.0 is the first attempt to address user's comments and concerns. METHODS: The majority of the article text is taken directly from Version 2.0 of the AMCP Format for Formulary Submissions published by the AMCP in October 2002. CONCLUSION: The AMCP and the FMCP believe that the AMCP Format is a tool that will help health systems establish a record of commitment to rational decision making, thus gaining the confidence of patients, clinicians, and members. While providing manufacturers a vehicle for communicating the scientifically based value of their product to a health system, the required evidence to substantiate that value argument allows a pharmacy and therapeutics committee to determine the clinical benefits of a drug, verify any cost savings the drug may generate, and determine the overall cost consequences to their health system. The AMCP Format for Formulary Submissions is an essential tool to evaluate medications, but requires thoughtful consideration as it is used.

Academies and Institutes↗

PubMedDate not supplied

Cost of chronic hepatitis B infection in the United States.

GOALS: To estimate the direct medical costs associated with chronic hepatitis B (CHB) infection in the United States. BACKGROUND: Approximately 240,000 new cases of hepatitis B infection occur annually in the United States. There are estimated to be 1.25 million sufferers of CHB in the United States. However, the economic impact of these infections has not been well studied. STUDY: We conducted a retrospective cohort analysis using administrative healthcare claims data to estimate costs for six health states associated with CHB infection. The six states were as follows: 1) CHB, 2) compensated cirrhosis, 3) decompensated cirrhosis, 4) liver transplantation, 5) transplant care >12 months following transplant, and 6) hepatocellular carcinoma. Patients in each health state were identified using diagnostic and procedure codes, and their utilization was tracked during their time in that health state. To estimate costs, we used reimbursed amounts and adjusted to year US 2000 dollars. RESULTS: Average annual costs for patients in each health state were as follows: CHB, US 761 dollars; compensated cirrhosis, US 227 dollars; decompensated cirrhosis, US 11,459 dollars; liver transplant, US 86,552 dollars; transplant care >12 months following transplant, US 12,560 dollars; and hepatocellular carcinoma, US 7,533 dollars. Medications contributed the largest proportion of costs in CHB and compensated cirrhosis disease states, while hospitalizations were the largest cost component in the other health states. CONCLUSIONS: This analysis provides estimates of the annual costs of complications of hepatitis B infection in the United States. The most progressive health states were associated with significantly higher costs.

Cohort Studies↗

PubMedDate not supplied

Global epidemiology of hepatitis B virus.

The burden of hepatitis B virus (HBV) disease and efforts to control infection will determine the future size of the population requiring treatment of HBV infection. To quantify the current prevalence of HBV infection and to reexamine the epidemiology of HBV infection, a structured review was conducted that focused on available primary literature for over 30 countries worldwide. The prevalence of chronic HBV infection continues to be highly variable, ranging over 10% in some Asian and Western Pacific countries to under 0.5% in the United States and northern European countries. The current global estimate of the number of HBV infected individuals is 350 million. Routes of transmission include vertical (mother to child or generation to generation through close contact and sanitary habits), early life horizontal transmission (through bites, lesions, and sanitary habits), and adult horizontal transmission (through sexual contact, intravenous drug use, and medical procedure exposure) and are evident to varying degrees in every country. Younger age at acquisition of infection continues to be the most important predictor of chronic carriage. However, the choice of serologic markers, temporal influences, and representativeness of the study population limit comparability of HBV seroprevalence results. HBV vaccination programs will decrease the future global burden of HBV infection and evidence of reduced burden is mounting in country-specific populations, but vaccination programs have still not been implemented in all countries, thereby maintaining reservoirs of infection and continued HBV transmission. Regardless of vaccination, large numbers of persons are infected with HBV or will become infected. Preventing the most severe HBV disease consequences in infected individuals, such as cirrhosis and hepatocellular carcinoma, will require appropriate therapeutic agents.

Global Health↗

PubMedDate not supplied

A computer simulation model of the natural history and economic impact of chronic obstructive pulmonary disease.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a major health problem with high societal costs. The Global Initiative for Chronic Lung Disease (GOLD) has identified a need for health economics data for COPD. For chronic diseases, such as COPD, where the natural history of disease is lifetime, a modeling approach for economic evaluation may be more realistic than prospective, piggy-backed clinical trials or specific COPD cohort studies. Simulation models can be used to extrapolate clinical data beyond the limited time frame of clinical trials, to analyze subgroups of patients or to explore uncertainty regarding the results by using sensitivity analysis techniques. Our purpose has been to develop a flexible computer simulation model for COPD that will represent disease progression and GOLD recommendations, useful for economic evaluations of new medicines to meet the needs of various payer requirements for reimbursement and resource allocation. METHODS: This article describes a two-dimensional Markov model, which uses data from multiple sources about disease progression, exacerbation frequency and duration, mortality, costs, burden of illness, and the relationships between those variables. The model is evaluated using stochastic uncertainty analysis, it allows comparison of treatments affecting different disease mechanisms, and it uses primary data validated against published sources. RESULTS: We have evaluated two hypothetical interventions treating different features of the disease (lung function decline and acute exacerbations). These analyses show that reducing lung function decline must be a long-term strategy compared to reducing the number of exacerbations. It was necessary to have a long term like 30 years, with 10,000 patients and 20% increase in price, or 20 years with equal prices to show cost-effectiveness with statistical significance for a treatment that reduces lung function decline. CONCLUSIONS: Our study shows the value of modeling as a tool for evaluating different scenarios and for combining several sources of data, to provide estimates that would otherwise be unavailable. Clinical trials of this size and duration would be unrealistic.

Computer Simulation↗

PubMedDate not supplied

Cost-effectiveness of fondaparinux compared with enoxaparin as prophylaxis against venous thromboembolism in patients undergoing hip fracture surgery.

OBJECTIVE: To evaluate the cost-effectiveness of fondaparinux relative to enoxaparin as prophylaxis against venous thromboembolism (VTE) in patients undergoing hip fracture surgery. METHODS: A decision analysis model was created to simulate the impact of fondaparinux 2.5 mg once daily relative to enoxaparin 30 mg twice daily on patient outcomes and costs over various time points up to 5 years after surgery. Probabilities for the analysis were estimated for a hypothetical cohort of 1000 patients undergoing hip fracture surgery in the United States receiving either fondaparinux or enoxaparin according to comparative trial results. Resource use and costs (2003 dollars) were obtained from large health-care databases. Outcome measures were rates of symptomatic VTE events, health-care costs, and incremental cost-effectiveness ratios. RESULTS: Fondaparinux is estimated to prevent an additional 30 VTE events (per 1000 patients) at 3 months compared with enoxaparin, producing savings of 103 dollars at discharge, 290 dollars over 1 month, 361 dollars over 3 months, and 466 dollars over 5 years. The results remain robust to clinically plausible variation in input parameters and assumptions. CONCLUSIONS: Fondaparinux improves outcomes and is cost-saving over a broad range of assumptions compared with enoxaparin for prophylaxis of VTE after hip fracture surgery.

Anticoagulants↗