A cost-effectiveness analysis of lisdexamfetamine dimesylate in the treatment of adults with attention-deficit/hyperactivity disorder in the UK

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a chronic neurobehavioral disorder in children that may persist into adulthood. Lisdexamfetamine dimesylate (LDX) is approved in many countries for ADHD treatment in children, adolescents, and adults.

OBJECTIVES

Estimate the cost-effectiveness of LDX as a first- or second-line treatment for adults with ADHD from the United Kingdom (UK) National Health Service (NHS) perspective compared with methylphenidate extended release (MPH-ER) and atomoxetine (ATX).

METHODS

A 1-year decision-analytic model was developed. Health outcomes included response, non-response and inability to tolerate. Efficacy data were obtained from a mixed-treatment comparison (MTC). Response was a score of 1 or 2 on the Clinical Global Impression-Improvement scale. Tolerability was assessed by discontinuation rates due to adverse events. Utilities were identified via a systematic literature review. Health care resource use estimates were obtained via a survey of clinicians. Daily drug costs were estimated from mean doses reported in the trials used in the MTC. One-way and probabilistic sensitivity analyses (PSAs) were performed.

RESULTS

LDX dominated MPH-ER and ATX; reducing mean per-patient annual cost by £5 and £200, and increasing mean quality-adjusted life years (QALYs) by 0.005 and 0.009, respectively. In the PSA, the probability of cost-effectiveness for LDX vs. MPH-ER and ATX at a threshold of £20,000 per QALY was 61% and 80%, respectively.

CONCLUSIONS

From the perspective of the UK NHS, LDX is likely to provide a cost-effective treatment for adults with ADHD. This conclusion may be drawn with more certainty in comparison with ATX than with MPH-ER.

A Cost-Utility Analysis of Lisdexamfetamine Versus Atomoxetine in the Treatment of Children and Adolescents with Attention-Deficit/Hyperactivity Disorder and Inadequate Response to Methylphenidate

BACKGROUND

An economic analysis from the perspective of the UK National Health Service (NHS) evaluated the cost effectiveness of lisdexamfetamine dimesylate (LDX) compared with atomoxetine in children and adolescents with attention-deficit/hyperactivity disorder who have had an inadequate response to methylphenidate.

METHODS

A 1-year decision-analytic model was constructed, with the health outcomes "response", "nonresponse", and "unable to tolerate". Clinical data were taken from a head-to-head, randomized controlled trial in inadequate responders to methylphenidate. Response to treatment was defined as a score of 1 (very much improved) or 2 (much improved) on the Clinical Global Impression-Improvement subscale. Tolerability was assessed by discontinuation rates owing to adverse events. Utility weights were identified via a systematic literature review. Healthcare resource use estimates were obtained via a survey of clinicians. Daily drug costs were derived from British National Formulary 2012 costs and mean doses reported in the trial. One-way and probabilistic sensitivity analyses (PSAs) were performed.

RESULTS

The comparison of LDX with atomoxetine resulted in an estimate of an incremental cost-effectiveness ratio of £1802 per quality-adjusted life-year (QALY). The result was robust in a wide range of sensitivity analyses; results were most sensitive to changes in drug costs and efficacy. In the PSA, assuming a maximum willingness to pay of £20,000 per QALY, LDX versus atomoxetine had an 86 % probability of being cost effective. In 38 % of PSA runs, LDX was more effective and less costly than atomoxetine.

CONCLUSIONS

From the perspective of the UK NHS, LDX provides a cost-effective treatment option for children and adolescents who are inadequate responders to methylphenidate.

Cost effectiveness of darunavir/ritonavir combination antiretroviral therapy for treatment-naive adults with HIV-1 infection in Canada

OBJECTIVE

The AntiRetroviral Therapy with TMC114 ExaMined In naive Subjects (ARTEMIS) clinical trial examined the efficacy and safety of two ritonavir-boosted protease inhibitors (PI/r), darunavir/r 800/100 mg once daily (QD) and lopinavir/r 800/200 mg daily, both used in combination with tenofovir disoproxil fumarate/emtricitabine. This study aimed to assess the cost effectiveness of the darunavir/r regimen compared with the lopinavir/r regimen in treatment-naive adults with HIV-1 infection in Canada.

METHODS

A Markov model with a 3-month cycle time and six CD4 cell-count-based health states (>500, 351-500, 201-500, 101-200, 51-100, and 0-50 cells/mm(3)) followed a cohort of treatment-naive adults with HIV-1 infection through initial darunavir/r or lopinavir/r combination therapy and a common set of subsequent regimens over the course of their remaining lifetimes. Population characteristics and transition probabilities were estimated from the ARTEMIS clinical trial and other trials. Costs (in 2014 Canadian dollars), utilities, and mortality were estimated from Canadian sources and published literature. Costs and health outcomes were discounted at 5% per year. One-way and probabilistic sensitivity analyses were performed, including a simple indirect comparison of the darunavir/r initial regimen with an atazanavir/r-based regimen.

RESULTS

In the base-case lifetime analysis, individuals receiving initial therapy with the darunavir/r regimen experienced 0.25 more quality-adjusted life-years (QALYs) with lower antiretroviral drug costs (-$14,246) and total costs (-$18,402) than individuals receiving the lopinavir/r regimen, indicating that darunavir/r dominated lopinavir/r. In an indirect comparison with an atazanavir/r-based regimen, the darunavir/r regimen remained the dominant choice, but with lower cost savings (-$2,303) and QALY gains (0.02). Results were robust to a wide range of other changes in input parameter values, population characteristics, and modeling assumptions. The probabilistic sensitivity analysis demonstrated that the darunavir/r regimen was cost effective compared with the lopinavir/r regimen in over 86% of simulations for willingness-to-pay thresholds between $0 and $100,000 per QALY gained.

CONCLUSIONS

Darunavir/r 800/100 mg QD may be a cost-effective PI/r component of initial antiretroviral therapy for treatment-naive adults with HIV-1 infection in Canada.

Multicountry burden of chronic hepatitis C viral infection among those aware of their diagnosis: a patient survey

BACKGROUND

The World Health Organization has called for global and regional assessments of the burden of hepatitis C (HCV) along with country-specific patient profiles to better inform healthcare policy. The present investigated the characteristics and burden of patients reporting a diagnosis of HCV infection in the US, France, Germany, Italy, Spain, the UK, urban China, and Japan using a consistent methodology of patient-reported surveys.

METHODS

The 2010 5EU (N = 57,805), 2009 US (N = 75,000), 2008/2009 Japan (N = 37,683), and 2009/2010 urban China (N = 33,261) waves of the National Health and Wellness Survey were used as the data source. Within each country, patients with a self-reported diagnosis of HCV were compared with those who did not report a diagnosis of HCV on sociodemographics, health behaviors, comorbidities, and health outcomes (e.g., Short Form-12v2). The effect of HCV was examined using regression analysis applying sampling weights.

RESULTS

The prevalence of HCV ranged from 0.26% (China) to 1.42% (Italy). Patients in Japan and Italy (61.60 and 61.02 years, respectively) were the oldest, while patients in the US were the most likely to be obese (39.31%) and have concomitant anxiety (38.43%) and depression (46.05%) compared with other countries. Pooling countries and adjusting for sociodemographics, health behaviors, and comorbidities, HCV was associated with significantly lower physical component summary scores (b = -2.51) and health utilities (b = -0.04) and greater overall work impairment (b = 8.79), physician visits (b = 2.91), and emergency department visits (b = 0.30) (all p<.05). The effects on health status were strongest in the US and UK while the effects on healthcare resource use were strongest in Japan.

CONCLUSIONS

HCV was associated with a significant humanistic and economic burden. These results suggest that the manifestation of the HCV burden, and the profile of the patients themselves, varied dramatically by country. Successful disease management should be cognizant of region-specific unmet needs.

Budget impact analysis-principles of good practice: report of the ISPOR 2012 Budget Impact Analysis Good Practice II Task Force

BACKGROUND

Budget impact analyses (BIAs) are an essential part of a comprehensive economic assessment of a health care intervention and are increasingly required by reimbursement authorities as part of a listing or reimbursement submission.

OBJECTIVES

The objective of this report was to present updated guidance on methods for those undertaking such analyses or for those reviewing the results of such analyses. This update was needed, in part, because of developments in BIA methods as well as a growing interest, particularly in emerging markets, in matters related to affordability and population health impacts of health care interventions.

METHODS

The Task Force was approved by the International Society for Pharmacoeconomics and Outcomes Research Health Sciences Policy Council and appointed by its Board of Directors. Members were experienced developers or users of BIAs; worked in academia and industry and as advisors to governments; and came from several countries in North America and South America, Oceania, Asia, and Europe. The Task Force solicited comments on the drafts from a core group of external reviewers and, more broadly, from the membership of the International Society for Pharmacoeconomics and Outcomes Research.

RESULTS

The Task Force recommends that the design of a BIA for a new health care intervention should take into account relevant features of the health care system, possible access restrictions, the anticipated uptake of the new intervention, and the use and effects of the current and new interventions. The key elements of a BIA include estimating the size of the eligible population, the current mix of treatments and the expected mix after the introduction of the new intervention, the cost of the treatment mixes, and any changes expected in condition-related costs. Where possible, the BIA calculations should be performed by using a simple cost calculator approach because of its ease of use for budget holders. In instances, however, in which the changes in eligible population size, disease severity mix, or treatment patterns cannot be credibly captured by using the cost calculator approach, a cohort or patient-level condition-specific model may be used to estimate the budget impact of the new intervention, accounting appropriately for those entering and leaving the eligible population over time. In either case, the BIA should use data that reflect values specific to a particular decision maker's population. Sensitivity analysis should be of alternative scenarios chosen from the perspective of the decision maker. The validation of the model should include at least face validity with decision makers and verification of the calculations. Data sources for the BIA should include published clinical trial estimates and comparator studies for the efficacy and safety of the current and new interventions as well as the decision maker's own population for the other parameter estimates, where possible. Other data sources include the use of published data, well-recognized local or national statistical information, and, in special circumstances, expert opinion. Reporting of the BIA should provide detailed information about the input parameter values and calculations at a level of detail that would allow another modeler to replicate the analysis. The outcomes of the BIA should be presented in the format of interest to health care decision makers. In a computer program, options should be provided for different categories of costs to be included or excluded from the analysis.

CONCLUSIONS

We recommend a framework for the BIA, provide guidance on the acquisition and use of data, and offer a common reporting format that will promote standardization and transparency. Adherence to these good research practice principles would not necessarily supersede jurisdiction-specific BIA guidelines but may support and enhance local recommendations or serve as a starting point for payers wishing to promulgate methodology guidelines.

Immunonutrition for patients undergoing elective surgery for gastrointestinal cancer: impact on hospital costs

Background

Oral or enteral dietary supplementation with arginine, omega 3 fatty acids and nucleotides (known as immunonutrition) significantly improve outcomes in patients undergoing elective surgery. The objective of the study was to determine the impact on hospital costs of immunonutrition formulas used in patients undergoing elective surgery for gastrointestinal cancer.

Methods

US hospital costs of stay with and without surgical infectious complications, and average cost per day in the hospital for patients undergoing elective surgery for gastrointestinal cancer were estimated using data from the Healthcare Cost and Utilization Project’s 2008 Nationwide Inpatient Sample. These costs were then used to estimate the impact of perioperative immunonutrition on hospital costs using estimates of reduction in infectious complications or length of stay from a meta-analysis of clinical trials in patients undergoing elective surgery for gastrointestinal cancer. Sensitivity of the results to changes in baseline complication rates or length of stay was tested.

Results

From the meta-analysis estimates, use of immunonutrition resulted in savings per patient of $3,300 with costs based on reduction in infectious complication rates or $6,000 with costs based on length of hospital stay. Cost savings per patient were present for baseline complication rates above 3.5% or when baseline length of stay and infectious complication rates were reduced to reflect recent US data for those with upper and lower GI elective cancer surgery (range, $1,200 to $6,300).

Conclusions

Use of immunonutrition for patients undergoing elective surgery for gastrointestinal cancer is an effective and cost-saving intervention.

Updating and confirming an industry-sponsored pharmacoeconomic model: comparing two antipsychotics in the treatment of schizophrenia

OBJECTIVE

This study updated a 2001 decision economic model that used indirect data and confirmed its findings by developing a new cost-effectiveness model by using now available head-to-head data. The models compared olanzapine with ziprasidone in the treatment of schizophrenia in the United States.

METHODS

A decision analytic modeling approach was used to estimate annual health-care costs and health outcomes, incorporating events such as response, relapse, and suicide. Patients without response to first-line treatment switched to the other comparator. Decision tree probabilities were extracted from head-to-head studies and other published clinical literature. Direct health-care costs and quality-adjusted life-years (QALYs) were estimated on the basis of resource use and utility weights for initial and relapse episodes, maintenance therapy, and extended episodes of illness. Disutilities associated with treatment-emergent adverse events were included.

RESULTS

Consistent with the 2001 model, this model found that first-line treatment with olanzapine is associated with fewer hospital days, fewer days with extrapyramidal symptoms, and higher QALYs than is first-line treatment with ziprasidone. Total costs were lower for the olanzapine pathway ($70,232-$72,776 vs. $73,086-$73,310 in the Positive and Negative Syndrome Scale analysis) due to the cost savings associated with reduced health-care resource use. The incremental cost per QALY gained indicated that the olanzapine pathway dominated the ziprasidone pathway.

CONCLUSIONS

Decision analytic models should be continuously assessed against new data. This case study shows that incorporating new data confirmed results of a previously published model in which olanzapine was associated with better expected health outcomes and lower total health-care costs than was ziprasidone.

Cost-effectiveness of prasugrel in a US managed care population

OBJECTIVE

Decision-makers in the US may be interested in the applicability to their populations of cost-effectiveness results generated from clinical trial populations.

METHODS

An economic model estimating the cost-effectiveness of prasugrel plus aspirin relative to clopidogrel plus aspirin for patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) was developed from a managed care organization (MCO) perspective. The model estimated 15-month cardiovascular events or bleeding-related outcomes, life expectancy, and costs for patients who received thienopyridine treatment during and after a PCI following a diagnosis of ACS. Post-ACS event rates for patients treated with clopidogrel were from an MCO. The relative risks of these events with prasugrel compared with clopidogrel were from a head-to-head clinical trial.

RESULTS

The results of the base-case analysis indicated that, in an MCO population, use of prasugrel-based therapy rather than clopidogrel-based therapy at current prices resulted in cost-savings and fewer clinical events over the 15 months after an ACS diagnosis followed by PCI. At possible lower prices for generic clopidogrel-based therapy, the cost-effectiveness ratio for prasugrel-based therapy compared with clopidogrel-based therapy was between $6643 and $13,906 per life-year gained. The results were most sensitive to the relative costs of the two treatments and the cost for hospital stays.

LIMITATIONS

Limitations of the study included lack of follow-up of patients disenrolling from the MCO before the end of the 15-month observation period, the assumption of equal relative risks of events in an MCO as in the clinical trial, and the lack of information on the ratio of cost to charges in the MCO database.

CONCLUSIONS

Use of prasugrel-based therapy compared with clopidogrel-based therapy in ACS patients having a PCI resulted in cost-savings at current prices and favorable cost-effective ratios at likely generic prices for clopidogrel-based therapy because of offsetting savings in the costs of rehospitalization.

Cost effectiveness of tiotropium for chronic obstructive pulmonary disease: a systematic review of the evidence

BACKGROUND

Tiotropium has been shown to reduce exacerbations and improve quality of life for patients with chronic obstructive pulmonary disease (COPD), a lung disease characterized by a persistent and progressive airflow limitation.

OBJECTIVES

To present a systematic literature review of the cost effectiveness of treatment with tiotropium compared with other currently used treatments for COPD.

METHODS

A systematic search was performed via PubMed, the Cochrane database, and EMBASE from 2002 to 2009. Methods and results by study design and by country were compared.

RESULTS

Seventeen studies were included in the review. Study designs were characterized as follows: modeling based on clinical trial data, and empirical analysis based on either clinical trial or observational data. Comparing monotherapy regimens (12 studies), all study designs found that treatment with tiotropium was associated with lower costs for hospitalisation and other non-drug services. Total costs, including the costs of maintenance drugs, were lower with tiotropium in some, but not all, of the studies. Tiotropium was shown to be cost effective based on commonly accepted benchmark values. Limitations of the review included the wide variety of outcome measures used in different studies, the limited number of observational database studies for monotherapy, and limited data for combination therapy regimens.

CONCLUSIONS

The main conclusions of the economic evaluations derived from clinical trial data at the time of product approval and from later observational data reflecting clinical use are similar: use of tiotropium monotherapy is associated with lower hospital and other non-drug costs and better health outcomes and is either cost saving or cost effective compared with other maintenance monotherapies.

Adherence to guidelines for sensitivity analysis: cost-effectiveness analyses of dual oral antiplatelet therapy

OBJECTIVE

Cost-effectiveness analyses of new treatments for cardiovascular disease frequently require input parameters whose values are known with uncertainty due to limited data. The objective of this paper is to examine the extent to which published sensitivity analyses addressing this uncertainty adhere to Health Technology Assessment (HTA) guidelines.

RESEARCH DESIGN AND METHODS

A systematic review of published cost-effectiveness analyses was performed for an example drug treatment scenario, dual oral antiplatelet therapy compared with aspirin alone following acute coronary syndromes and/or percutaneous coronary intervention. The following medical literature databases were searched for articles published from January 1997 to June 2007: PubMed, Cochrane Collaboration, EMBASE and the Health Economic Evaluation Database (HEED). Evidence tables were created to show the sensitivity of the cost-effectiveness estimates to changes in the input parameter values, as well as the data sources used for the reference-case and sensitivity analysis input parameter values. The extent to which the sensitivity analyses adhered to HTA guidelines were also examined.

RESULTS

Cost-effectiveness ratios were most sensitive to changes in the efficacy of dual antiplatelet therapy and reference-case model assumptions about costs beyond the trial period. Although alternative values tested in the sensitivity analysis for some input parameters were based on observed ranges or distributions, alternative values tested for many other input parameters were assumed without justification.

CONCLUSIONS

Sensitivity analyses in the cost-effectiveness studies of dual oral antiplatelet therapy were not fully adherent with HTA guidelines. In particular, long-term costs and benefits were not always included in the sensitivity estimates, the impact of differential effects on death and myocardial infarction was not explored, and justification for the alternative parameter values tested was not always provided.

Nonresponse, partial response, and failure to achieve remission: humanistic and cost burden in major depressive disorder

OBJECTIVE

To characterize the spectrum of clinical outcomes achieved with depression treatment and the associated impact on quality of life (QOL), functional status, overall well-being, health-care costs, and productivity.

SOURCES

Electronic databases including Medline were searched for English language sources between 1995 and 2007 using key words of depression, nonresponse, partial response, and remission and QOL, functional status, utility, cost, and productivity.

STUDY SELECTION

Relevant abstracts were obtained for 488 references and full-text articles were reviewed that included primary data and compared outcomes by treatment response. Data were abstracted from 26 full-text articles.

DATA ABSTRACTION

Detailed evidence tables were prepared with the relevant data as well as information on the study design. All data abstracted were checked for accuracy. synthesis: Treatment remitters and partial responders reported clinically and statistically significant improvements in QOL, functional status, and overall well-being compared to nonresponders. Annual health-care costs and productivity losses were significantly lower for remitters and partial responders compared to nonresponders.

CONCLUSIONS

The reduced disease burden for remitters and partial responders compared to nonresponders indicates that new treatment strategies that improve the rates of response/remission with initial treatment might have value to patients and to society.

Rate, type, and cost of pelvic organ prolapse surgery in Germany, France, and England

OBJECTIVE

To estimate the rate, type and costs of surgical interventions for pelvic organ prolapse (POP) in Germany, France, and England.

STUDY DESIGN

We identified the number, rate, and type of hospital admissions for pelvic floor surgery in 2005 from national hospital activity databases in each country: the German Hospital Episode, the French Medical Care Program Information System, and the National Health Service England Hospital Episode Statistics. Costs to the payer were estimated using the Diagnosis-Related Group reimbursement rates for each country.

RESULTS

In 2005, the number (rate) of admissions for POP surgery was 36,854 (0.87 per 1000 women) in Germany, 36,679 (1.14 per 1000 women) in France, and 28,959 (1.13 per 1000 women) in England. Admissions for POP surgery constituted 10.4%, 16.7% and 16.9% of all admissions for female genital tract therapeutic interventions in Germany, France and England, respectively. At least 20% of hysterectomies were performed for the primary indication of POP. 57.4%, 45.0%, and 40.1% of all admissions for POP surgery included a hysterectomy. The costs to payers were 144,236,557 euro, 83,067,825 euro, and 81,030,907 euro in Germany, France, and England, respectively.

CONCLUSION

Burden and costs associated with POP surgery are substantial in the three countries studied. Thus, programs aimed at reducing the burden of this disease are desirable.

Rate, type, and cost of invasive interventions for uterine myomas in Germany, France, and England

STUDY OBJECTIVE

The objective of our study was to quantify the rate, type, and cost of interventions for uterine myomas to payers in Germany, France, and England.

DESIGN

Computations using data from national hospital activity databases.

DESIGN CLASSIFICATION

II-3.

SETTING

Hospital admissions in Germany, France, and England.

PATIENTS

Women admitted for a surgical or radiologic intervention for uterine myomas.

INTERVENTIONS

Surgical or radiologic interventions for uterine myomas.

MEASUREMENTS AND MAIN RESULTS

We identified the number and type of hospital admissions involving surgical or radiologic interventions for uterine myomas, through the analysis of national hospital activity databases from each country. We calculated the costs of these hospitalizations to payers in these countries using the diagnosis-related group reimbursement rates. In 2005, the number (rate) of hospital admissions involving interventions for uterine myomas was 64 299 (1.53/1000 women) in Germany, 37 787 (1.17/1000 women) in France, and 18 274 (0.71/1000 women) in England. The annual costs of these interventions to payers were euro212 313 090 in Germany, euro73 278 270 in France (excluding surgeon and anesthetist fees for interventions in the private sector), and euro52 674 672 in England. The percentage of interventions for uterine myomas that included a hysterectomy was 84.9% in Germany, 59.7% in France, and 64.1% in England.

CONCLUSION

The number of admissions and costs associated with interventions for uterine myomas are substantial in the 3 European countries studied. Hysterectomy is the most frequent surgical intervention used to treat uterine myomas. The results in this article provide useful information for policy makers wishing to evaluate the cost effectiveness and budget impact of new, less invasive interventions.

Principles of good practice for budget impact analysis: report of the ISPOR Task Force on good research practices--budget impact analysis

OBJECTIVES

There is growing recognition that a comprehensive economic assessment of a new health-care intervention at the time of launch requires both a cost-effectiveness analysis (CEA) and a budget impact analysis (BIA). National regulatory agencies such as the National Institute for Health and Clinical Excellence in England and Wales and the Pharmaceutical Benefits Advisory Committee in Australia, as well as managed care organizations in the United States, now require that companies submit estimates of both the cost-effectiveness and the likely impact of the new health-care interventions on national, regional, or local health plan budgets. Although standard methods for performing and presenting the results of CEAs are well accepted, the same progress has not been made for BIAs. The objective of this report is to present guidance on methodologies for those undertaking such analyses or for those reviewing the results of such analyses.

METHODS

The Task Force was appointed with the advice and consent of the Board of Directors of ISPOR. Members were experienced developers or users of budget impact models, worked in academia, industry, and as advisors to governments, and came from several countries in North America, Oceana, Asia, and Europe. The Task Force met to develop core assumptions and an outline before preparing a draft report. They solicited comments on the outline and two drafts from a core group of external reviewers and more broadly from the membership of ISPOR at two ISPOR meetings and via the ISPOR web site.

RESULTS

The Task Force recommends that the budget impact of a new health technology should consider the perspective of the specific health-care decision-maker. As such, the BIA should be performed using data that reflect, for a specific health condition, the size and characteristics of the population, the current and new treatment mix, the efficacy and safety of the new and current treatments, and the resource use and costs for the treatments and symptoms as would apply to the population of interest. The Task Force recommends that budget impact analyses be generated as a series of scenario analyses in the same manner that sensitivity analyses would be provided for CEAs. In particular, the input values for the calculation and the specific cost outcomes presented (a scenario) should be specific to a particular decision-maker's population and information needs. Sensitivity analysis should also be in the form of alternative scenarios chosen from the perspective of the decision-maker. The primary data sources for estimating the budget impact should be published clinical trial estimates and comparator studies for efficacy and safety of current and new technologies as well as, where possible, the decision-maker's own population for the other parameter estimates. Suggested default data sources also are recommended. These include the use of published data, well-recognized local or national statistical information and in special circumstances, expert opinion. Finally, the Task Force recommends that the analyst use the simplest design that will generate credible and transparent estimates. If a health condition model is needed for the BIA, it should reflect health outcomes and their related costs in the total affected population for each year after the new intervention is introduced into clinical practice. The model should be consistent with that used for the CEA with regard to clinical and economic assumptions.

CONCLUSIONS

The BIA is important, along with the CEA, as part of a comprehensive economic evaluation of a new health technology. We propose a framework for creating budget impact models, guidance about the acquisition and use of data to make budget projections and a common reporting format that will promote standardization and transparency. Adherence to these proposed good research practice principles would not necessarily supersede jurisdiction-specific budget impact guidelines, but may support and enhance local recommendations or serve as a starting point for payers wishing to promulgate methodology guidelines.

Minimizing resistance consequences after virologic failure on initial combination therapy: a systematic overview

OBJECTIVE

To identify optimal first-line therapies based on the rate of virologic success (VS) and the preservation of future treatment options in antiretroviral therapy (ART)-naive subjects.

DESIGN

Systematic overview of genotypic resistance mutations from clinical trials of combination ART.

METHODS

Various sources were searched for studies in ART-naive subjects providing virologic response rates and genotypes from subjects with virologic failure. The International AIDS Society-USA genotypic resistance guidelines were used to calculate regimen resistance cost (RCreg) and number of active drug (AD) scores for each regimen and to rank the regimens.

RESULTS

Intra- and interstudy comparisons showed higher VS rates for nonnucleoside reverse transcriptase inhibitor (NNRTI) regimens (range: 51%-76%) and boosted protease inhibitor (boosted PI) regimens (range: 55%-79%). Boosted PI failures had the lowest RCreg (range: 0.12-0.21) and the highest AD (range: 19.80-20.18) scores. NNRTI failures had higher RCreg (range: 0.00-1.22) and lower AD (range: 16.83-21) scores.

CONCLUSIONS

NNRTI and boosted PI regimens provide the highest rates of VS in treatment-naive HIV-infected persons. Treatment option scores were higher in subjects who failed boosted PI- containing regimens versus NNRTI-containing regimens, however.

Optimal assignment of treatments to health states using a Markov decision model: an introduction to basic concepts

Assessing the cost effectiveness of a new health intervention often requires modelling to estimate the impact of the intervention on cost, survival and quality of life over the lifetime of a cohort of patients. Markov modelling is a methodology that is commonly employed to estimate these long-term costs and benefits. As commonly used, these models assume that the patients continue to get the treatments assigned regardless of the change in health states. In this paper, we describe an extension to the Markov modelling approach, called Markov decision modelling. Such a model starts with a set of health states and treatments and optimally assigns treatments to each of the health states. A Markov decision model can be used to identify the optimal treatment strategy not just for the initial disease state, but also as the disease state changes over time. We present a dynamic programming approach to identifying the optimal assignment of treatments, and illustrate this methodology using an example. The Markov decision modelling approach provides an efficient way of identifying optimal assignment of treatments to health states, but, like the standard Markov model, may be of limited use when probabilities of future events depend on past history in a complex fashion. Even with its limitations, Markov decision models offer an opportunity for health economists to inform healthcare decision-makers on how to modify current treatment pathways to incorporate new treatments as they become available.

Drug persistency patterns for patients treated with rivastigmine or donepezil in usual care settings

OBJECTIVE

To compare levels of persistency with 2 cholinesterase (ChE) inhibitors--rivastigmine and donepezil--for the treatment of Alzheimer's disease (AD) through the use of administrative claims data.

METHODS

This retrospective cohort study identified treatment-naive, community-based AD patients having an initial prescription (index event) for rivastigmine or donepezil between June and December 2000, in the United States, from pharmacy claims in a proprietary administrative claims database. Patients were excluded if they received either drug during the 180 days prior to their index prescription or if they did not have continuous plan enrollment during this period and for at least 90 days following the index date. The probability of treatment discontinuation within the first 60 days of treatment was estimated. Time to treatment discontinuation was analyzed for the cohort of patients that remained on therapy > or =60 days as well as for subgroups of the cohort reaching either approved or maximum recommended doses of donepezil or rivastigmine. Treatment discontinuation was defined as either a stop of therapy (no prescription refill within 60 days of estimated completion of prior prescription) or a switch to an alternative AD drug. Kaplan-Meier survival and proportional hazard model analyses were performed. Proportion of days covered (PDC) by an AD therapy was also evaluated in each quarter during the first year of follow-up.

RESULTS

Of the newly treated AD study population, 30.4% (171/563) of rivastigmine patients and 31.2% (583/1,871) of donepezil patients discontinued treatment within 60 days of starting therapy (P = 0.72). For the cohort of patients that remained on therapy > or =60 days, the mean time to treatment discontinuation was 331 days (95% confidence interval [CI], 307-355) for rivastigmine patients (n = 392) versus 337 days (95% CI, 322-352) for donepezil patients (n = 1288). The proportion of patients with a PDC > or =80% after 12 months of follow-up was 23% for the donepezil group and 19% for the rivastigmine group (P = 0.34). For the cohort subgroup that reached an approved dose, the mean time to treatment discontinuation was 346 days (95% CI, 318-374) for rivastigmine patients (n = 282) versus 338 days (95% CI, 323-353) for donepezil patients (n = 1,283). For the cohort subgroup that reached the maximum recommended dose, the mean time to treatment discontinuation was 396 days (95% CI, 343-449) for rivastigmine patients (n = 61) versus 364 days (95% CI, 344-384) for donepezil patients (n = 712).

CONCLUSION

Newly treated AD patients in a usual care setting who initiate therapy with either rivastigmine or donepezil have similar levels of persistency with treatment.

Conditions for the near equivalence of cost-effectiveness and cost-benefit analyses

The equivalence of cost-effectiveness analysis (CEA) and cost-benefit analysis (CBA) has been vigorously debated in the health economic literature. In this paper we review and refine the conditions for the equivalence of CEA and CBA. The previously stated conditions require that 1) each individual's willingness to pay (WTP) per quality-adjusted life year (QALY) is constant and does not vary with the magnitude of QALY gains, and 2) the WTP per QALY is identical for every individual in society. Based on mathematical programming formulations of CEA and CBA, we note that condition 2 can be replaced with two other conditions, which together are less restrictive than the requirement that every individual have the same WTP per QALY. Even with this less restrictive set of conditions, CEA and CBA are unlikely to be equivalent under real world conditions. When CEA and CBA do lead to different resource allocation decisions, the most appropriate framework for health economic analysis depends on the perspective regarding distribution issues. We also examine the equivalence of two different definitions of CEA provided in the literature and discuss the problems that could arise when there are multiple optima.

A Monte Carlo simulation for modelling outcomes of AIDS treatment regimens

Healthcare providers are often faced with the need to make treatment decisions about antiretroviral therapy regimens for patients with HIV infection without definitive information as to the optimal sequencing of drug regimens. In this paper we describe our model developed to simulate the impact of differing drug sequencing strategies used in the treatment of patients with HIV/AIDS. In addition, we present the methods used to estimate the efficacy and duration of antiretroviral therapies to populate the model at baseline. We conducted a hypothetical application of the model using three alternative series of therapies: a series containing no drug therapy, a series starting with a protease inhibitor-containing regimen, and a series starting with a non-nucleoside reverse transcriptase inhibitor-containing regimen. The model described in this article can be used to compare and contrast the relative impact of different treatment guidelines in the absence of necessary clinical data and may serve as a means of evaluation until clinical trials or observational databases provide guidance as to the optimal treatment regimen(s). The model is flexible and permits adaptation to the changing treatment environment in HIV infection.

Cost-effectiveness model of cytomegalovirus management strategies in renal transplantation. Comparing valaciclovir prophylaxis with current practice

BACKGROUND

Cytomegalovirus (CMV) disease may occur following renal transplantation and has been shown to have health and cost consequences in this setting.

OBJECTIVE

To compare the cost effectiveness of different CMV management strategies for renal transplant patients: prophylaxis with (i) oral valaciclovir or (ii) intravenous ganciclovir; viral testing for CMV followed by (iii) pre-emptive therapy with intravenous ganciclovir or (iv) adjustment of immunosuppression and intensive monitoring; or (v) waiting to treat when CMV disease develops.

METHODS

A decision-tree model was constructed that included the different management strategies for the donor seropositive/recipient seronegative (D+R-) population. Clinical outcomes for the D+R- population came from clinical trials. Treatment algorithms and costs for CMV syndrome and tissue invasive disease were developed from published literature and UK physician interviews. One- and 2-way sensitivity analyses were performed.

STUDY PERSPECTIVE

UK National Health Service.

RESULTS

Prophylaxis with either oral valaciclovir or intravenous ganciclovir dominated (lower costs and fewer cases of CMV disease) the pre-emptive treatment and wait-and-treat strategies. The cost per patient was from 157 Pounds to 438 Pounds higher with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis and the incremental cost per case of CMV disease avoided with valaciclovir prophylaxis ranged from 2243 Pounds to 8111 Pounds (1996 values). These results are sensitive to the efficacy of intravenous ganciclovir prophylaxis and CMV management costs.

CONCLUSIONS

For D+R- renal transplant patients, prophylaxis is the dominant (more effective and less costly) management strategy compared with pre-emptive and wait-and-treat strategies. The cost per patient with oral valaciclovir prophylaxis compared with intravenous ganciclovir prophylaxis is slightly higher in our base case scenario, but may be lower under reasonable alternative assumptions.

Assessing the Saskatchewan database for outcomes research studies of depression and its treatment

This study was conducted to evaluate the validity of using the Saskatchewan Health administrative claims databases for conducting depression research. To develop a claims-based definition of depression, we identified a cohort of individuals who began a "new" period of antidepressant use (no use 180 days prior) from which we selected a stratified random sample (n = 600) for medical record abstraction. The medical record diagnosis was used as the gold standard for judging our database definitions of depression. After defining a primary database definition of depression, we tried to refine it using medically probable scenarios and assessed refinement by agreement statistics. Defining depression with ICD9 codes 296 (affective disorders), 309 (adjustment reaction), and 311 (depressive disorders), the sensitivity (Se), specificity (Sp), positive (PV+) and negative predictive (PV-) values were: 71%, 85%, 86%, and 70%, respectively. Algorithms that limited the number of false-negatives resulted in: Se = 84% and PV- = 77% whereas those that limited false-positives resulted in: Sp = 90% and PV+ = 86%. Although our depression definition requires treatment with antidepressants, this definition will allow us to conduct future studies of depression and its treatment using the Saskatchewan Health databases.

Cost effectiveness of zanamivir for the treatment of influenza in a high risk population in Australia

OBJECTIVE

To use data from a clinical trial of zanamivir, a new antiviral drug, to estimate the costs and effectiveness of alternative treatment strategies for a high-risk population in Australia visiting a physician for treatment of influenza or influenza-like illness within 36 hours of symptom onset.

DESIGN AND SETTING

This was a modelling study using data from a randomised, double-blind, placebo-controlled trial with centres in Australia, New Zealand and South Africa. Cost data were taken from standard Australian sources.

METHODS

Efficacy data from the clinical trial were used to populate a computer model designed to estimate the costs and health outcomes associated with alternative treatments for influenza and influenza-like illness. Only patients who consulted the physician within 36 hours of symptom onset were included in this trial. Cost data were used to translate the clinical data into treatment cost estimates.

RESULTS

Treatment with zanamivir for this high risk population results in an incremental cost of $A14.20 per day of symptoms avoided in the base case. The cost per quality-adjusted life-year (QALY) gained is $A11,715. The results are sensitive to several parameter values, including the influenza-positive rate and the impact of zanamivir on days to alleviate symptoms and hospitalisation.

CONCLUSIONS

Influenza is costly for the high risk population who seek physician treatment. Treatment with zanamivir for this population is cost effective based on an $A78,000 per QALY benchmark. Zanamivir could be cost saving if it reduces the hospitalisation rate.

Impact of zidovudine-based triple combination therapy on an AIDS drug assistance program

A static deterministic model was used to estimate the effect of the shift to a triple combination therapeutic standard on the annual AIDS Drug Assistance Program (ADAP) budget, total medical care expenditures, and population health outcomes for New York (NY) state ADAP enrollees. The model used opportunistic disease incidence data from the Multicenter AIDS Cohort Study (MACS) and other studies. Costs of treating opportunistic infections (OIs) and other HIV complications with each type of therapy were derived from treatment algorithms and standard unit costs. CD4+ cell counts were used as an index of need for OI prophylaxis and for determining OI incidence. Treatment with zidovudine-based combination therapy has been shown to increase CD4+ cell counts and reduce OI incidence. The model estimated that a change from monotherapy to triple therapy would have increased NY ADAP budget expenditures per enrollee by 115%. However, total medical system costs per ADAP enrollee (including ADAP costs) would decrease by 0.4% in the base case as a result of reduction in OIs and other HIV sequelae and associated costs. Results are sensitive to the assumed percentage of people taking combination therapy as well as to the assumptions made about the impact of the combination therapy on CD4+ cell count. Total ADAP budget impacts will depend on the growth in ADAP enrollment as a result of the availability of more effective therapies. In conclusion, this model demonstrates how access to newer, more effective HIV drug treatments can reduce the costs of treating OIs and provide major health benefits for ADAP enrollees.

Potential savings in the cost of caring for Alzheimer's disease. Treatment with rivastigmine

OBJECTIVE

To estimate savings in the cost of caring for patients with Alzheimer's disease (AD) during 6 months, 1 year and 2 years of treatment with rivastigmine. An intermediate objective was to estimate the relationship between disease progression and institutionalisation.

DESIGN AND SETTING

We assessed the relationship between Mini-Mental State Examination (MMSE) score and institutionalisation using a piecewise Cox proportional hazard model. To estimate cost savings from treatments lasting 6 months, 1 year and 2 years, estimates of the probability of institutionalisation were integrated with data from two 6-month phase III clinical trials of rivastigmine and a hazard model of disease progression.

MAIN OUTCOME MEASURES AND RESULTS

Our data suggest that savings in the overall cost of caring for patients with mild and moderate AD can be as high as $US4839 per patient after 2 years of treatment. Furthermore, the probability of institutionalisation increases steadily as MMSE score falls. Among our study individuals, age, race, level of education and marital status were significant predictors of institutionalisation, whereas gender had little effect.

CONCLUSIONS

Using rivastigmine to treat AD results in a delay in disease progression for patients who begin treatment during the mild or moderate stages of the disease. By delaying the probability that a patient will be institutionalised, the cost of caring for AD patients can be significantly reduced.

Savings in the cost of caring for patients with Alzheimer's disease in Canada: an analysis of treatment with rivastigmine

OBJECTIVE

To estimate per-patient potential cost savings using rivastigmine in the treatment of Alzheimer's disease (AD) in Canada.

BACKGROUND

In recent years, new members of a class of pharmaceuticals known as cholinesterase inhibitors have been introduced for the treatment of patients with AD. Two recent studies conducted in the United Kingdom and the United States estimated potential cost savings from the new cholinesterase inhibitor rivastigmine. The present study combined the disease-progression model used in those 2 studies with Canadian costs to estimate per-patient potential savings resulting from the treatment of AD in Canada.

METHODS

Efficacy data from 2 pivotal, phase III clinical trials of rivastigmine were used in a hazard model of disease progression to estimate long-term differences in cognitive functioning between patients receiving rivastigmine and patients receiving no treatment. We used the Mini-Mental State Examination (MMSE) score as our measure of disease progression. We also used Canadian costs of AD care, estimated as a function of MMSE score, to estimate cost savings experienced by treated patients compared with patients receiving no treatment. All costs and cost savings are presented in 1997 Canadian dollars. We used a societal perspective in this analysis.

RESULTS

Rivastigmine was estimated to delay the transition to more severe stages of AD by up to 188 days for patients with mild AD after 2 years of treatment. For patients with mild-to-moderate and moderate disease, this delay was estimated to be 106 and 44 days, respectively. For patients with the mild stage of AD, estimated average daily cost savings (excluding the cost of rivastigmine) ranged from Can $0.45 per patient per day at 6 months to Can $6.44 per patient per day after 2 years of treatment. For all patients, these estimated average daily cost savings ranged from a low of Can $0.71 per patient per day after 6 months of treatment to a high of Can $4.93 per patient per day after 2 years.

CONCLUSION

On average, treatment with rivastigmine yields savings in the direct cost of caring for AD patients that exceed the cost of the drug after 2 years of treatment.

Annual health outcomes and treatment costs for schizophrenia populations

This article describes a model that estimates annual patient health and cost outcomes for schizophrenia under alternative treatment scenarios. We estimate these outcomes for typical antipsychotics and show how treatment with atypical antipsychotics could have an impact on these outcomes. Patients are divided into 5 subcategories--newly diagnosed, no episode, acute episode(s), extended care, and institutionalized--and patient health and cost outcomes are estimated for each category. The proportion of people in each category is estimated for U.S. general, state mental hospital, and community mental health populations. Outcomes include extrapyramidal and moderate/severe schizophrenia symptom days, employed days, suicides, hospital days, and health costs. For patients treated with typical antipsychotics, annual per-patient symptom days ranged from 55 to 365 and costs ranged from $16,000 to $57,000, depending on disease severity. Atypical antipsychotics may reduce symptoms and costs through better efficacy for negative symptoms and better compliance.

Willingness to pay as a measure of health benefits

In this paper, we discuss the use of cost-benefit analysis (CBA) for evaluating new healthcare interventions, present the theoretical basis for the use of willingness to pay as a method for valuing benefits in a CBA and describe how to obtain willingness-to-pay (WTP) measures of health benefits and how to use these values in a CBA. We review selected economic studies on consumer demand and consumer surplus and studies presenting WTP estimates for healthcare interventions. The theoretical foundations of willingness to pay as a measure of commodity value are rooted in consumer demand theory. The area under the fixed income consumer demand curve represents the consumer's maximum willingness to pay for the commodity. We identify 3 types of potential benefits from a new healthcare intervention, namely patient benefits, option value and altruistic value, and suggest WTP questions for valuing different combinations of these benefits. We demonstrate how responses to these questions can be adjusted for income effects and incorporated into economic evaluations. We suggest that the lack of popularity of CBAs in the health area is related to the perceived difficulty in valuing health benefits as well as concern over how CBA incorporates the distribution of income. We show that health benefits can be valued using simple survey techniques and that these values can be adjusted to any desired income distribution.

A pharmacoeconomic model for the treatment of influenza

OBJECTIVE

The aim of this study was to develop a generic treatment algorithm for influenza and influenza-like illness (ILI) that could be used to estimate the costs and outcomes of current and new treatments for influenza in different countries for different patient subgroups.

METHODS

A series of possible treatment pathways was identified and the probabilities of different patient subgroups following each pathway were estimated by using the published literature. The health outcomes and health service use and unit costs for each pathway were estimated from trial data and standard data sources. An interactive computer model was created, the base-case input parameter values were assigned, and estimates of the current costs of influenza and ILI in different population subgroups estimated. Sensitivity analyses were performed by changing input parameter values.

RESULTS

The average healthcare cost of influenza and ILI per person in the US was $US72 for the general population and $US330 for a high risk population (1997 values). The average total cost per patient (healthcare cost plus productivity losses) was $US320 for the general population and $US546 for a high risk population. These costs are sensitive to changes in the proportion of patients visiting a physician and to the proportion of patients hospitalised with complications of the disease. Days to alleviate major symptoms and other health outcome measures are sensitive to the percentage of patients who receive antiviral therapy as well as to the efficacy of this therapy.

CONCLUSIONS

The costs and health outcomes of influenza and ILI depend on the extent to which patients visit a physician, the use of antiviral drugs, and the incidence of complications requiring hospital care. The computer model will allow decision-makers to assess the cost effectiveness and the potential budget impact of new antivirals for treating influenza.

Cost-effectiveness model of adjunctive lamotrigine for the treatment of epilepsy

OBJECTIVE

To predict the cost-effectiveness of lamotrigine by evaluating the costs and health outcomes in treated patients.

BACKGROUND

Lamotrigine adjunctive therapy has been found to be associated with decreased seizure frequency and severity in patients who are refractory to treatment with the older antiepileptic drugs (AEDs).

METHODS

We used a cost-effectiveness clinical decision analysis framework to assess the impact of these clinical benefits on patient health care use. The measure of effectiveness was seizure-free days gained. The measures of health care resource use included hospitalizations, outpatient and emergency department visits, surgery, and AEDs. Medical care use and cost estimates were derived from clinical trial data and published sources. Costs and effectiveness (incremental costs per seizure-free days gained) of lamotrigine adjunctive therapy versus older AEDs were compared in patients refractory to previous treatment during three time periods: the start-up year, the second year when decisions about surgery were made, and all subsequent years.

RESULTS AND CONCLUSIONS

The model predicts that use of lamotrigine would be associated with an overall reduction in use of other direct medical care resources (hospitalizations, outpatient visits, diagnostic and laboratory tests, and surgery). For a 10-year time horizon, the estimated cost-effectiveness ratio is $6.9 per seizure-free day gained. The model provides a flexible framework to analyze the effect of new antiepileptic drugs.

The role of cost-consequence analysis in healthcare decision-making

A greater understanding of value associated with new pharmaceutical products should lead to better decision-making. Most commonly cost-effectiveness ratios (CERs) are used to indicate value; however, researchers have recently shown that CER estimates are rarely used by decision-makers in making formulary decisions. In this article, a cost-consequence approach to estimating the value for money of a new treatment for a specific disease is described. Using a cost-consequence approach, the impact of the new treatment on lifetime resource use and costs (including specific healthcare service use and costs, and productivity losses) and health outcomes (including disease symptoms, life expectancy and quality of life) for an individual or group of individuals is estimated and presented in a tabular format. The cost-consequence format is more likely to be approachable, readily understandable and applied by healthcare decision-makers than a simple CER. The decision-maker may use selected items from the cost-consequence analysis to compute composite measures of drug value, such as cost per life-year gained or cost per quality-adjusted life-year (QALY) gained. In general, the cost-consequence approach, by making the impact of the new treatment as comprehensive and transparent as possible, will enable decision-makers to select the components most relevant to their perspective and will also give them confidence that the data are credible to use as the basis for resource allocation decisions.

Comparison of valaciclovir and acyclovir for the treatment of herpes zoster in immunocompetent patients over 50 years of age: a cost-consequence model

A method was developed for modeling the costs and consequences of treating varicella zoster viral infections to clinical data generated in a pivotal phase III clinical trial of valaciclovir versus acyclovir for the treatment of acute herpes zoster in immunocompetent patients over 50 years of age. Direct medical costs and indirect costs (productivity losses) were modeled using unit costs applicable in the United States. Compared with acyclovir, valaciclovir reduced average direct medical costs per patient by 17% ($60.01) and indirect costs by an average of 25% ($46.54). Median duration of pain was reduced by 13 days for valaciclovir compared with acyclovir in the intent-to-treat population or by 19 days in patients with pain after rash healing. The cost variables described in the model (drug costs, cost of treating long-term pain, physician visits, hospitalization, treatment of severe ocular involvement, productivity losses) were tested by sensitivity analysis. Total costs associated with valaciclovir treatment remained lower than those with acyclovir over the range of the analysis.

Functional status in depressed patients: the relationship to disease severity and disease resolution

BACKGROUND

We set out to measure the impact of depression and its clinical resolution on patients' functional status.

METHOD

The Work and Social Disability Scale (WSDS), a five-category investigator-rated scale measuring patient functional status, was completed at baseline and study discontinuation in a 56-day, open, uncontrolled study evaluating the safety of a sustained release (SR) formulation of bupropion in 3167 patients at 105 sites. To be included in the study, patients had to be 18 years or older, have a diagnosis of depression, and be considered appropriate for treatment with bupropion SR. The proportion of patients in each WSDS category, for those patients taking more than 7 days of bupropion SR (N = 2915), was assessed at screen and study discontinuation. The percentage of patients with improved WSDS scores at 56 days was also measured for all patients and correlated with patient and treatment characteristics.

RESULTS

Of the patients entering the trial, 61.8% were markedly or severely impaired in their work or social activities, and only 5.4% were mildly or not impaired. At study discontinuation, more than 54% of patients were judged by the investigator to have very much or much improvement in their clinical symptoms. Results on the WSDS correlated with the clinical improvements; only 22.3% were markedly or severely impaired; and 50.0% were mildly or not impaired at study discontinuation. In addition, 63.9% of patients had less work or social disability at the end of the trial than at study entry. Functional status improved more in patients who had not previously been treated for the episode, had more severe depression at study entry, and had a higher dose and duration of treatment with bupropion SR.

CONCLUSION

The results show that depression results in significant impairment in patients' functional status. Functional status improved in patients treated with bupropion SR for up to 56 days. This improvement was highly correlated with improvement in clinical symptoms and was related to patient characteristics at study entry as well as to treatment patterns during the study.

Estimating the dollar value of health outcomes from drug-abuse interventions

OBJECTIVES

People who abuse drugs suffer from a host of medical problems that impose costs on both the abusers and society as a whole. Drug-abuse treatment and other interventions can help alleviate these medical problems, leading to health status improvements for chronic drug users and reduced social costs. The authors' dual purpose here is to (1) propose a theoretically rigorous yet easy-to-apply methodology for estimating the health-related costs of drug abuse and (2) demonstrate the methodology by estimating the potential dollar value of avoiding adverse health consequences as a result of successful drug-abuse interventions.

METHODS

The authors' proposed multiattribute quality-adjusted life year methodology for estimating the value of avoiding morbidity and mortality involves eight steps to be followed sequentially. The framework is based on developing a common unit of well-being (i.e., quality-adjusted life year) that can be applied to all types of health conditions. If all health states can be denominated in this common unit, then the process of valuation is straightforward and consistent across all types of illnesses and diseases. The methodology is relatively inexpensive to execute because the estimation procedures are not complicated technically and the data demands are modest. Also, this approach incorporates elements from several disciplines, including psychology, epidemiology, medicine, and economics. Finally, the proposed methodology is flexible enough to cover a wide range of illnesses and diseases so that consistent and comparable estimates can be generated.

RESULTS

The authors estimate the dollar value of avoiding acute hepatitis B, human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), hypertension, bacterial pneumonia, sexually transmitted diseases, and tuberculosis for a white male aged 32 years. The authors' results illustrate that estimated avoided morbidity values can vary significantly across the range of health consequences associated with drug abuse. At the upper end of the range, the value of avoiding only the morbidity associated with a single case of HIV/AIDS is approximately $157,811 for the period beginning with transmission of HIV, through late-stage HIV and AIDS, and ending just before death.

CONCLUSIONS

People who abuse drugs suffer from many medical problems in addition to their addiction. The proposed approach for estimating the dollar value of avoiding adverse health consequences provides policy analysts, evaluators, and researchers a method to calculate theoretically based benefit estimates for use in a benefit-cost analysis of drug-abuse interventions.

Economic impact of treatment of HIV-positive pregnant women and their newborns with zidovudine. Implications for HIV screening

OBJECTIVES

To estimate the economic impact of (1) treating pregnant women who are human immunodeficiency virus (HIV)-positive with zidovudine and (2) voluntary screening programs for pregnant women for HIV infection and offering treatment with zidovudine to those found to be HIV-positive.

MAIN OUTCOME MEASURES

Number of cases of pediatric HIV infection and costs of screening, zidovudine treatment, and pediatric HIV infection treatment.

DESIGN

Health care costs associated with treatment of HIV-positive pregnant women and their newborns are estimated as the costs of zidovudine and its administration and the reduction in costs of treating pediatric HIV infection. The lifetime costs of pediatric HIV infection are derived from the published literature. Estimates of the reduction in maternal-to-fetal transmission rates are taken from the AIDS [acquired immunodeficiency syndrome] Clinical Trials Group (ACTG) Protocol 076. Costs of a voluntary screening program include costs of screening tests and counseling. Sensitivity and threshold analyses are performed to determine the impact of changes in input parameter values including zidovudine treatment costs, efficacy of treatment, costs of pediatric HIV infection, prevalence of HIV infection in pregnant women, screening test sensitivity and specificity, and pregnancy termination rates on the results.

RESULTS

Assuming transmission rates are reduced from 25.5% to 8.3% as found in the ACTG 076 trial, treatment costs of $104,502 for 100 HIV-positive pregnant women and their newborns are offset by the reduction of $1,701,333 associated with fewer cases of pediatric HIV infection for a net savings of $1,596,831. The sensitivity and threshold analyses show that overall cost savings from treatment of HIV-positive pregnant women and their newborns are achieved for a wide range of possible maternal treatment costs, efficacy rates, and lifetime pediatric HIV treatment costs. In the base-case analysis for the voluntary screening program, overall cost savings are seen when HIV prevalence rate among pregnant women is greater than 4.6 per 1000. However, this threshold prevalence rate is sensitive to changes In parameter value-especially pediatric HIV treatment costs, counselling costs, efficacy of treatment, and years of additional HIV treatment for the pregnant women.

CONCLUSIONS

Offering zidovudine treatment to pregnant women known to be HIV-positive will decrease the number of cases of pediatric HIV infection and reduce health care costs. Voluntary screening programs for pregnant women will further decrease the number of cases of pediatric HIV infection. The effect of a screening program on health care costs varies according to HIV prevalence and the costs associated with the screening program.

Cost-consequence models for varicella-zoster virus infections

Three cost-consequence models were developed for treatment of infections due to varicella-zoster virus (VZV) with acyclovir in immunocompetent patients--adult- and childhood-onset chickenpox, and herpes zoster (shingles) in adults. For chickenpox, separate models allow examination of differences in severity and impact of the disease for children and adults, as well as in the management of civilians and adults in military service. Each model includes direct medical costs, indirect costs and health-related productivity loss, symptom and quality of life impact, and model assumptions and conclusions. Alternatives of treatment and no treatment are addressed. Quality of life impact is conceptualized in terms of a quality-adjusted life-days decrement due to VZV symptoms of importance to the patient, such as pain, rash, and itching. As experience and data become available, alternative agents such as valacyclovir and famciclovir for the treatment of patients with herpes zoster should be included in the modeling process.

Estimating the value of a generic quality-of-life measure

In this paper, data from a clinical trial of a new antiviral agent for treating patients with zoster are used to answer the following question: Does the Nottingham Health Profile (NHP) add to the information obtained from the clinical measures? Three ways in which the NHP could add information are measured. First, Cox's regression analysis is used to determine whether health-related quality-of-life scores obtained at diagnosis give information about disease prognosis. Second, changes in mean NHP scores in different dimensions are computed after pain resolution to determine whether NHP scores provide more sensitive indicators of disease resolution. Third, linear regression is used to determine whether the impacts of disease on quality of life are measured adequately by the clinical parameters. These analyses show that use of the physical mobility and energy dimensions of the NHP increases understanding of disease prognosis; demonstrates the continuing impact of zoster on patients' sleep patterns and energy levels, disease symptoms not included as clinical measures, that persist after the cessation of zoster-associated pain; and gives a measure of the impact of zoster on the patient, which includes unmeasured and measured levels of severity.

Synthetic surfactant for rescue treatment of respiratory distress syndrome in premature infants weighing from 700 to 1350 grams: impact on hospital resource use and charges

To determine the impact of the use of synthetic surfactant on hospital resource use and charges, we analyzed the economic data from a multicenter, randomized, placebo-controlled clinical trial of synthetic surfactant in infants with neonatal respiratory distress syndrome and birth weights between 700 and 1350 gm. Two 5 ml/kg doses of a synthetic surfactant (Exosurf Neonatal) or air placebo were administered to 419 infants who were receiving mechanical ventilation and had an arterial/alveolar oxygen tension ratio < 0.22. In addition to the clinical endpoints for safety and efficacy, data were collected on length of hospital stay, days in the neonatal intensive care unit, days of mechanical ventilation, days of oxygen supplementation, and hospital charges until the infant reached 1 year adjusted age. Growth and development of infants who received synthetic surfactant therapy in the study and survived to 1 year adjusted age were equivalent to those of the survivors in the air placebo group. For 1-year survivors, synthetic surfactant reduced the average length of stay at the different levels of care needed during the hospitalization such as neonatal intensive care unit days, days of mechanical ventilation, and days of oxygen supplementation. For nonsurvivors, synthetic surfactant increased the average length of stay, especially at more intense levels of care. Total hospital charges for the initial hospitalization and through 1 year adjusted age for a hypothetic cohort of 100 infants treated with synthetic surfactant were, on average, the same as those for a comparable cohort of infants in the air placebo group. These results indicate that rescue therapy with synthetic surfactant in infants with respiratory distress syndrome and birth weights from 700 to 1350 gm can result in significantly improved survival without significant increases in hospital charges.

Economic outcomes of colfosceril palmitate rescue therapy in infants weighing 1250g or more with respiratory distress syndrome: results from a randomised trial

An analysis of the economic data from a multicentre, randomised, placebo-controlled clinical trial of colfosceril palmitate in infants with neonatal respiratory distress syndrome (NRDS) and birthweights of 1250g or more is presented. Two 5 ml/kg (67.5 mg/kg) doses of a synthetic surfactant (colfosceril palmitate) or air placebo were administered to 1237 infants who were receiving mechanical ventilation and had an arterial/alveolar oxygen tension ratio of less than 0.22. In addition to the clinical end-points for safety and efficacy, data were collected on length of hospital stay, days in the neonatal intensive care unit, days on mechanical ventilation, days on oxygen, and hospital charges until the child reached 1-year adjusted age. One-year adjusted age is attained when the time elapsed since birth is equal to 365 days plus the number of days of prematurity. Rescue treatment with synthetic surfactant therapy has been shown to reduce the incidence of complications of NRDS. Growth and development of infants who received colfosceril palmitate therapy in the study and survived to 1-year adjusted age were equivalent to those of the survivors in the air placebo group. For the cohort of treated infants, colfosceril palmitate reduced the average length of stay at 2 levels of care needed during both the initial hospitalisation (a reduction of 8 days overall and 5 days in intensive care) and all first year hospitalisations (a reduction of 9 days overall and 5 days in intensive care). Total hospital charges for the initial hospitalisation and through 1-year adjusted age for a hypothetical cohort of 100 infants treated with colfosceril palmitate were less than those for a comparable cohort in the air placebo group. The results would, therefore, suggest that rescue therapy with colfosceril palmitate in infants with NRDS and birthweights over 1250g can result in substantial reductions in hospital resource utilisation and charges in addition to the clinical benefits associated with its use.

Potential health benefits of nutrition label changes

OBJECTIVES

The Nutrition Labeling and Education Act of 1990 mandates the Food and Drug Administration to promulgate changes in nutrition labeling regulations. This study investigates the potential health benefits associated with expected changes in food consumption resulting from the act.

METHODS

This paper provides four estimates of the potential health benefits from the dietary changes expected to occur as a result of the 1990 act. The upper bound estimates begin with the premise that all consumers will adopt the daily reference values of total fat, saturated fat, and cholesterol. The lower bound estimate is based on consumers' responses to a shelf-labeling program sponsored by the Food and Drug Administration in the 1980s. A computer model developed by Dr. Warren Browner and his associates was used to estimate the health benefits from reduced nutrient intakes.

RESULTS

Estimates of the number of discounted life-years gained nationwide for the first 20 years after the implementation of the act range from a high of 1.2 million to a low of 40,000.

CONCLUSIONS

The results of the study highlight that relatively small changes in nutrient intakes may generate large public health benefits.

A quality-of-life method for estimating the value of avoided morbidity

We developed a quality-of-life method for valuing changes in health status. Our model determines changes in health attributes for different illnesses and then estimates the dollar value of the corresponding welfare losses. We used our quality-of-life approach to estimate willingness to pay to avoid asthma, a headache, a cough, bronchitis, and arthritis. Estimates derived using our method are similar to those obtained from more expensive and restrictive traditional methods.

Cost-effectiveness analysis of the use of digoxin immune Fab (ovine) for treatment of digoxin toxicity

Each year many people have digitalis toxicity severe enough to require extensive hospital treatment. Digoxin immune Fab[ovine]-Fab fragments (Digibind) have been shown to reverse digitalis toxicity and substantially reduce the risk of death. Data were used from uncontrolled studies of patients treated with Fab fragments as well as clinical, medical care and pharmacokinetic data from symptomatically treated patients to derive estimates of the difference in clinical outcomes and medical care costs when treating with this new drug. Estimates are derived separately for treatment of patients with toxicity that is immediately life-threatening and patients whose manifestations are not immediately life-threatening. Treatment with Fab fragments reduces the probability of dying more for the seriously toxic than for the less seriously toxic patient. Such treatment is generally associated with an increase in total medical care costs for the seriously toxic patients because more of them survive the toxic episode and require additional medical care before discharge from the hospital. For these patients, the estimated cost per life-year saved is between $1,900 and $5,400. When Fab fragments are used to treat less seriously toxic patients, total medical care costs decrease because of an estimated decreased number of days in the coronary care unit and decreased use of pacemakers and other aggressive treatments.

Benefit-cost analysis of hepatitis B vaccine programs for occupationally exposed workers

The Occupational Safety and Health Administration proposed a vaccination program for workers exposed to the hepatitis B virus 12 or more times per year. We performed a benefit-cost analysis of the proposed regulation and an expanded rule that covers all at-risk workers, regardless of the number of exposures. The annualized cost of the proposed vaccination program is estimated at $60.4 million. We estimated the dollar benefit of the program using two methods. The first estimates the avoided cost of medical care, prophylaxis, and lost productivity at $124 million annually. The second approach includes the value of avoided pain and suffering from hepatitis B, thus increasing the total dollar benefit to $679 million. Although both methods indicate benefits are greater than program costs, the valuation of avoided pain and suffering substantially increases net benefits. Furthermore, providing the vaccine to all exposed workers is cost-effective if one or more cases of hepatitis B are avoided per 6500 workers annually.