Vivek Pawar

Economic model of a birth cohort screening program for hepatitis C virus

Recent research has identified high hepatitis C virus (HCV) prevalence among older U.S. residents who contracted HCV decades ago and may no longer be recognized as high risk. We assessed the cost‐effectiveness of screening 100% of U.S. residents born 1946‐1970 over 5 years (birth‐cohort screening), compared with current risk‐based screening, by projecting costs and outcomes of screening over the remaining lifetime of this birth cohort. A Markov model of the natural history of HCV was developed using data synthesized from surveillance data, published literature, expert opinion, and other secondary sources. We assumed eligible patients were treated with pegylated interferon plus ribavirin, with genotype 1 patients receiving a direct‐acting antiviral in combination. The target population is U.S. residents born 1946‐1970 with no previous HCV diagnosis. Among the estimated 102 million (1.6 million chronically HCV infected) eligible for screening, birth‐cohort screening leads to 84,000 fewer cases of decompensated cirrhosis, 46,000 fewer cases of hepatocellular carcinoma, 10,000 fewer liver transplants, and 78,000 fewer HCV‐related deaths. Birth‐cohort screening leads to higher overall costs than risk‐based screening (

Comparative Cost-Effectiveness of Stereotactic Body Radiation Therapy Versus Intensity-Modulated and Proton Radiation Therapy for Localized Prostate Cancer

80.4 billion versus

Methods of Model Calibration: Observations from a Mathematical Model of Cervical Cancer

53.7 billion), but yields lower costs related to advanced liver disease (

Incorporating Calibrated Model Parameters into Sensitivity Analyses

31.2 billion versus

Calibrating Longitudinal Models to Cross-Sectional Data: The Effect of Temporal Changes in Health Practices

39.8 billion); birth‐cohort screening produces an incremental cost‐effectiveness ratio (ICER) of

Economic assessment of doripenem versus imipenem in the treatment of ventilator-associated pneumonia.

37,700 per quality‐adjusted life year gained versus risk‐based screening. Sensitivity analyses showed that reducing the time horizon during which health and economic consequences are evaluated increases the ICER; similarly, decreasing the treatment rates and efficacy increases the ICER. Model results were relatively insensitive to other inputs. Conclusion: Birth‐cohort screening for HCV is likely to provide important health benefits by reducing lifetime cases of advanced liver disease and HCV‐related deaths and is cost‐effective at conventional willingness‐to‐pay thresholds. (HEPATOLOGY 2012)

MO2 INCORPORATING CALIBRATED MODEL PARAMETERS INTO SENSITIVITY ANALYSES: DETERMINISTIC AND PROBABILISTIC APPROACHES

OBJECTIVE To determine the cost-effectiveness of several external beam radiation treatment modalities for the treatment of patients with localized prostate cancer. METHODS A lifetime Markov model incorporated the probabilities of experiencing treatment-related long-term toxicity or death. Toxicity probabilities were derived from published sources using meta-analytical techniques. Utilities and costs in the model were obtained from publicly available secondary sources. The model calculated quality-adjusted life expectancy and expected lifetime cost per patient, and derived ratios of incremental cost per quality-adjusted life year (QALY) gained between treatments. Analyses were conducted from both payer and societal perspectives. One-way and probabilistic sensitivity analyses were performed. RESULTS Compared to intensity-modulated radiation therapy (IMRT) and proton beam therapy (PT), stereotactic body radiation therapy (SBRT) was less costly and resulted in more QALYs. Sensitivity analyses showed that the conclusions in the base-case scenario were robust with respect to variations in toxicity and cost parameters consistent with available evidence. At a threshold of

PMD21 IS CYBERKNIFE A COST-EFFECTIVE OPTION FOR TREATING PROSTATE CANCER?

50,000/QALY, SBRT was cost-effective in 75% and 94% of probabilistic simulations compared to IMRT and PT, respectively, from a payer perspective. From a societal perspective, SBRT was cost-effective in 75% and 96% of simulations compared to IMRT and PT, respectively, at a threshold of

The Impact of Birth-Cohort Screening for Hepatitis C Virus (HCV) Compared With Current Risk-Based Screening on Lifetime Incidence of and Mortality From Advanced Liver Disease (AdvLD) in the United States (U.S.)

50,000/QALY. In threshold analyses, SBRT was less expensive with better outcomes compared to IMRT at toxicity rates 23% greater than the SBRT base-case rates. CONCLUSION Based on the assumption that each treatment modality results in equivalent long-term efficacy, SBRT is a cost-effective strategy resulting in improved quality-adjusted survival compared to IMRT and PT for the treatment of localized prostate cancer.

PIH22 EVALUATING THE COST-EFFECTIVENESS OF CERVICAL CANCER SCREENING AND HUMAN PAPILLOMAVIRUS VACCINATION STRATEGIES USING A MATHEMATICAL MODEL

Background: Mathematical models are commonly used to predict future benefits of new therapies or interventions in the healthcare setting. The reliability of model results is greatly dependent on accuracy of model inputs but on occasion, data sources may not provide all the required inputs. Therefore, calibration of model inputs to epidemiological endpoints informed by existing data can be a useful tool to ensure credibility of the results.Objective: To compare different computational methods of calibrating a Markov model to US data.Methods: We developed a Markov model that simulates the natural history of human papillomavirus (HPV) infection and subsequent cervical disease in the US. Because the model consists of numerous transition probabilities that cannot be directly estimated from data, calibration to multiple disease endpoints was required to ensure its predictive validity. Goodness of fit was measured as the mean percentage deviation of model-predicted endpoints from target estimates. During the calibration process we used the manual, random and Nelder-Mead calibration methods.Results: The Nelder-Mead and manual calibration methods achieved the best fit, with mean deviations of 7% and 10%, respectively. Nelder-Mead accomplished this result with substantially less analyst time than the manual method, but required more intensive computing capability. The random search method achieved a mean deviation of 39%, which we considered unacceptable despite the ease of implementation of that method.Conclusions: The Nelder-Mead and manual techniques may be preferable calibration methods based on both performance and efficiency, provided that sufficient resources are available.