Tuesday, October 20, 2009: 4:00 PM
Grand Ballroom, Salon 5 (Renaissance Hollywood Hotel)

* Candidate for the Lee B. Lusted Student Prize Competition

Session Chairs:
Elisabeth A.L. Fenwick, PhD and Ivar S.ønbø Kristiansen, PhD
4:00 PM
Karla Solheim, BS1, Dana Henry, MD2, Teresa N. Sparks, MD3, Brian Shaffer, MD4, Yvonne Cheng, MD, MPH4 and Aaron B. Caughey, MD, MPP, MPH, PhD5, (1)UCSF, San Francisco, CA, (2)Brigham and Women's Hospital, Boston, MA, (3)Brigham & Women's Hospital, San Francisco, CA, (4)University of California, San Francisco, CA, (5)University of California, San Francisco, San Francisco, CA

Purpose: To investigate the outcomes related to allowing a woman to labor for an additional 2 hours after 2 hours of “active phase arrest” instead of performing an immediate cesarean. 

Method: A decision analytic model comparing an additional 2 hours of attempted labor versus an immediate cesarean birth for women in “labor arrest” (no cervical dilation for 2 hours while in active labor) was designed.  Baseline assumptions were derived from the literature in terms of cost and morbidity and mortality of all modes of delivery, including recent data that suggest many women in 2 hours of active phase arrest will be able to achieve a vaginal birth if given additional time. We took into account the cost of prolonged labor, costs of each MOD, and cost of maternal mortality.  The major morbidities we investigated were shoulder dystocia, Erb's palsy, facial nerve palsy, and maternal and neonatal death.

Result: Continuing to labor for 2 additional hours was cost-effective at a savings of $2,013 per delivery.  It also resulted in 0.123 additional QALYs per delivery.

Conclusion: Allowing a woman who has been in active phase of labor arrest for 2 hours to continue to labor for an additional 2 hours is both cost-effective and predictive of better outcomes.  This model suggests that standards of care that recommend an immediate cesarean delivery after 2 hours of active phase arrest may warrant a review. Table: Cost-effectiveness of continuing to labor after 2 hours of labor arrest
Strategy Cost QALYs
Continue laboring $ 9,101 56.666
Cesarean delivery $11,114 56.543
Incremental Difference $ 2,013  0.123

4:15 PM
Torbjørn Wisløff, M.Sc., Norwegian Knowledge Centre for the Health Services, Oslo, Norway, Ivar Sønbø Kristiansen, MD, PhD, MPH, Institute of Health Economics, N-0317 Oslo, Denmark Norway and Dan Atar, MD, PhD, Oslo University Hospital Aker, Oslo, Norway

Purpose: To evaluate the cost-effectiveness of drug-eluting stents (DES) compared to bare metal stents (BMS) using data from registries and randomized controlled trials (RCT's).

Method: In most patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), one or more metal stents are implanted during the procedure to avoid collapsing of coronary arteries. During the last five years, there has been an ongoing debate regarding the relative effectiveness of BMS versus DES (the latter group consisting of either paclitaxel- (PES) or sirolimus-eluting (SES) stents). Meta-analyses performed arrive at conflicting results, partly because they include either RCT’s alone, or additionally patient registries claimed to represent “real-world” data. We developed a Markov model to follow patients for five years after the initial PCI. The model has half year-cycles with the following events: AMI, repeat revascularisation (PCI or CABG), and death. Probabilities of events are based on two Scandinavian registries (SCAAR and WDHR). Effectiveness of different DES compared to BMS was assessed based on either a meta-analysis of RCT’s (Stettler 2009), or data from the SCAAR registry (James 2009).

Result: Analyses based on RCT-data show that PES is cost-saving compared to BMS while SES is not cost-effective at the current Norwegian threshold for cost-effectiveness (approximately $90,000 per life-year gained). When the assessment was based on registries, PES was also the most cost-effective stent type ($14,000 per life year gained), however, the incremental net health benefit (INHB) of PES compared to SES or BMS was less pronounced. Probabilistic sensitivity analyses indicate a 56% probability of PES being the most cost-effective strategy based on effectiveness from RCT’s and a 75% probability based on registry data.

Conclusion: Replacing BMS by DES is cost-effective with a threshold value of $90,000 per QALY regardless whether this health-economic analysis is based on trial- or registry-data.

4:30 PM
Sandra Spronk, PhD1, Bob JH van Kempen, BSc1, Torbjørn Wisløff, M.Sc.2, Johanna L. Bosch, PhD3, Myriam G.M. Hunink, PhD, MD1 and Ivar Sønbø Kristiansen, MD, PhD, MPH4, (1)Erasmus MC, Rotterdam, Netherlands, (2)Norwegian Knowledge Centre for the Health Services, Oslo, Norway, (3)Erasmus Medical Center, Rotterdam, Netherlands, (4)Institute of Health Economics, N-0317 Oslo, Denmark Norway

Purpose: This value of information (VOI) analysis was conducted to inform decision makers whether additional research on one-time screening for abdominal aortic aneurysms (AAA) in 65-year-old men would be worthwhile and which key parameters would be most valuable in an experimental design.

Method: We performed a second-order Monte Carlo simulation, in which costs and health outcomes of a one-time screening program and current practice were simulated over a lifetime European societal perspective. Data on clinical effectiveness and costs were derived from a primary database and the literature. VOI analysis was used to estimate the expected benefit of future research to eliminate the decision uncertainty that remained after completion of the analyses. We estimated the total expected value of perfect information (EVPI) and the expected value of perfect partial information (EVPPI) to identify the key parameters of future studies. It was estimated that in Europe about 116000  65-year old men with an AAA could be screened annually and would therefore benefit from future research in this area. The expected benefit of future research was expressed in Euros per patient and Euros for the European population, assuming a 5-year effective lifetime of the screening program and a 3% discount rate.

Result: As long as decision makers place a higher value than €18452 on a QALY, it is cost-effective to adopt a one time screening for AAAs in 65-year-old men. Using a societal WTP threshold of €20000 per QALY, the EVPI was €247 per patient and the value of perfect information for each yearly cohort of 65-year-old men of the European population was estimated to be €132 Million. Using a WTP threshold of €50000 per QALY, the EVPI per patient was €162 and the population EVPI approximately €87 Million, indicating that more research is justified. The EVPPI indicated that the most relevant information in future research could be obtained from research that evaluates the total in-hospital costs after emergency versus elective repair and the probability of rupture of an AAA.

Conclusion: Acquiring additional information on one-time screening for AAAs in 65-year-old men is cost-effective. The focus should be on the total in-hospital costs after emergency versus elective repair and the probability of rupture of the AAA.

4:45 PM
Robert B. McQueen, MA, Pharmaceutical Outcomes Research Program, Department of Clinical Pharmacy, University of Colorado Denver School of Pharmacy, Aurora, CO, Samuel L. Ellis, Pharm.D., CDE, Department of Clinical Pharmacy, University of Colorado Denver School of Pharmacy, Aurora, CO and Patrick W. Sullivan, PhD, University of Colorado Denver School of Pharmacy, Aurora, CO

Purpose: Recent clinical evidence has shown that continuous glucose monitoring (CGM) devices can help reduce overall glycosylated hemoglobin (A1c) levels in adult patients, thereby decreasing the progression of complications of diabetes. However, the cost of CGM devices is significant for individuals and payers. The objective of this study is to determine the cost-effectiveness of CGM treatment with intensive insulin therapy compared to standard monitoring of blood glucose (SMBG) in adults with type 1 diabetes in the United States.

Method: A Markov cohort analysis was employed to model the long-term disease progression of 12 different diabetes disease states (including diabetes with no complications), using a cycle length of 1 year with a 33-year time horizon based on life expectancy. The analysis uses a societal perspective to model a population with a 20-year history of diabetes with mean age of 40. Costs are expressed in $US 2007, effectiveness in QALYs. Parameter estimates and their ranges were derived from the literature. Utility estimates were drawn from the EQ-5D catalogue developed by Sullivan et al. Probabilities were derived from the Diabetes Control and Complications Trial (DCCT), the United Kingdom Prospective Diabetes Study (UKPDS), and the Wisconsin Epidemiologic Study of Diabetic Retinopathy. Costs and QALYs were discounted at 3% per year. Univariate and Multivariate probabilistic sensitivity analyses were conducted using 10,000 Monte Carlo simulations.

Result: Compared to SMBG, use of CGM with intensive insulin treatment resulted in an expected improvement in effectiveness of 0.49 QALYs, and an expected increase in cost of $24,435, resulting in an ICER of approximately $50,000/QALY. For a willingness-to-pay (WTP) of $100,000/QALY, CGM with intensive insulin therapy was cost-effective in 70% of the Monte Carlo simulations.

Conclusion: CGM with intensive insulin therapy improves effectiveness at a higher cost compared to SMBG with intensive insulin therapy, and appears to be cost-effective relative to other societal health interventions. CGM with intensive insulin therapy may be a cost-effective option for patients with additional resources for treatment, or higher A1c levels (e.g., > 8%). The cost-effectiveness of CGM also compares favorably to other health interventions commonly accepted by payers in the U.S.

5:00 PM
Elbert S. Huang, MD, MPH1, Michael O'Grady, PhD2, Anirban Basu, PhD1, Aaron N. Winn, MPP3, Priya John, MPH1, Joyce Lee, MD, MPH4 and David O. Meltzer, MD, PhD1, (1)University of Chicago, Chicago, IL, (2)National Opinion Research Center at University of Chicago, Bethesda, MD, (3)Harvard, Cambridge, MA, (4)University of Michigan, Ann Arbor, MI

Purpose: Continuous glucose monitoring (CGM) has been found to improve glucose control in type 1 diabetes patients.  However, the cost-effectiveness of CGM has not been evaluated.  We estimate the incremental cost-effectiveness of CGM for patients with type 1 diabetes patients with sub-optimal (primary cohort, glycated hemoglobin (A1C)≥7.0%) and optimal glucose control (secondary cohort, A1C<7.0%).

Method: The cost-effectiveness analysis (CEA) was conducted from the societal perspective.  Our analysis was limited to JDRF-CGM trial populations where CGM produced a significant glycemic benefit (adult primary cohort, secondary cohort).  Trial subjects were randomized to continuous or standard glucose monitoring for 6 months.  Data on health state utilities (TTOs) and health service utilization were collected routinely.  We calculated incremental cost-effectiveness ratios (ICERs) expressed in 2007 US dollars for the within-trial period and extrapolated long-term (lifetime).costs and benefits using a simulation model of type 1 diabetes complications. 

Results:   During the 6 month trial, CGM subjects experienced a quality of life benefit (adult primary: 0.70 quality-adjusted weeks (QALWs) p=0.49; secondary: 1.39 QALWs, p=0.04) in addition to an improvement in glucose control.  The within-trial ICERs were approximately $400,000/QALY.  In the long-term CEA for the adult primary cohort, CGM was projected to reduce the lifetime probabilities of blindness (14.5612.00), amputation (10.539.13), and end-stage renal disease (ESRD) (4.41→2.37); the average gain in QALYs was 0.60.  The ICER was $98,679/QALY (95% confidence intervals (CI), -60,007 (4th quadrant), -86,582 (2nd quadrant).  For the secondary cohort, CGM was also projected to reduce probabilities of microvascular complications; the average gain in QALYs was 1.11.  The ICER was $78,943/QALY (95% CI, 14,644 (1st quadrant), -290,780 (2nd quadrant). In sensitivity analyses, if the benefit of CGM had been limited to improved glucose control, the ICER would exceed $400,000/QALY for the adult primary cohort and $900,000/QALY for the secondary cohort.  If daily CGM costs were ≤ $7/day, the ICER would be below $50,000/QALY.

Conclusions: The point estimates of ICERs based on long-term projections from the JDRF-CGM trials indicate that CGM is cost-effective among type 1 patients, although considerable uncertainty surrounds these estimates.  Subgroup analysis demonstrates heterogeneity in the quality of life impact and the economic value of CGM for patients with varying levels of glycemic control.  The value of CGM is greatly influenced by its ability to improve everyday quality of life. 

5:15 PM
Frank Kee, Professor, Karen J. Cairns, PhD, Andrew J. Hamilton, MB, BCh and Adele H. Marshall, PhD, Queen's University Belfast, Belfast, United Kingdom

Purpose: Cardiac First-Responder (CFR) schemes aim to improve survival from Sudden Cardiac Arrest (SCA), by reducing the time until administration of life-saving defibrillation, with volunteers paged to respond to possible SCA incidents alongside the Emergency Medical Services (EMS). Observational CFR trials have produced varying results in different geographical regions.  A Monte-Carlo simulation-based model has been constructed to capture the varying impact of mobile CFR schemes in different geographical regions, as part of a cost-utility analysis. Calculation results are presented for a particular rural region of the UK.   

Methods: Two interventions are compared over a 5-year period: treatment of SCA through standard EMS versus standard EMS combined with a CFR scheme. Within the model, occurrence of SCAs across a geographical region is assumed to follow a Poisson process, based on the at-risk population in small areas. For each SCA, the response-times of the EMS, together with any CFR responses (dependent on the roster scheme) are quantified. Parametric accelerated failure-time models are used to model these, depending on geographical location and other influential covariate information. The effectiveness of the scheme in a particular geographical region is determined by substituting response-times in a logistic-regression survival-to-hospital-discharge model, and utilising published quality-of-life utility-scores and life-expectancies. Incremental costs include the cost of capital set-up, annual revenue, additional hospitalisation and long-term care costs. After model-validation, the Incremental Cost-Effectiveness Ratio (ICER) has been calculated for a rural region, extending a previous one-way sensitivity analysis and incorporating second-order probabilistic sensitivity analysis.   

Results: Second-order probabilistic sensitivity analyses suggest response-times would be improved in this rural region through the addition of a 31-person CFR scheme with 45.9% (IQR:[43.8%-48.3%]) of SCAs reached within 8 minutes, compared to 35.6% (IQR:[34.5%-36.7%]) under EMS-only. An additional 16.5 QALYs would be gained (IQR:[8.1-26.5]) for the population of 185,795.  The ICER was £48,172/QALY (IQR:[£33,861-£85,893]). The ICER was less than the nominal National Health Service (NHS) National Institute of Clinical Excellence threshold of £30,000 in 17% of simulations. The ICER was sensitive to alterations in volunteer availability; sensitivity of the dispatch mechanism and training costs.   

Conclusion: The scheme would not be the most efficient use of NHS resources in this particular rural geography. However, it could start to address the existing imbalance in emergency-response provision found between rural and urban regions.