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Hypothetical Cohort (hypothetical + cohort)
Selected AbstractsA Cost-Benefit Analysis of External Hip Protectors in the Nursing Home SettingJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2005Lisa A. Honkanen MD Objectives: To estimate potential cost savings generated by a program of hip protectors in the nursing home from a Medicare perspective. Design: A state-transition Markov model considering short-term and long-term outcomes of hip protectors for a hypothetical nursing home population, stratified by age, sex, and functional status. Costs, transition probabilities between health states, and estimates of hip protectors' effectiveness were derived from published secondary data. Setting: Nursing home facilities in the United States. Participants: Hypothetical cohort of permanent nursing home residents aged 65 and older without a previous hip fracture. Intervention: Program of hip protectors reimbursed by Medicare. Measurements: Number of fractures, life years, and dollars saved. Results: Three pairs of hip protectors replaced annually would result in a weighted average lifetime absolute risk reduction for hip fracture of 8.5%, with net lifetime savings to Medicare of $223 per resident. When the annual cost of hip protectors is less than $151 per person, relative risk of fracture is less than or equal to 0.65 with hip protectors, or adherence is greater than 42%, hip protectors are cost saving to Medicare over a wide range of assumptions. Extrapolating these results to the estimated population of U.S. nursing home residents without a previous hip fracture, Medicare could save $136 million in the first year of a hip-protector reimbursement program. Conclusion: From a Medicare perspective, hip protectors are a cost-saving intervention in the nursing home setting when hip protector effectiveness is less than or equal to 0.65 over the remaining lifetime of subjects. [source] Cost-effectiveness of different treatment strategies with intrapartum antibiotic prophylaxis to prevent early-onset group B streptococcal diseaseBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2005M.E. van den Akker-van Marle Objective To estimate the costs and effects of different treatment strategies with intrapartum antibiotic prophylaxis to prevent early-onset group B streptococcal (GBS) disease in the Netherlands. The treatment strategies include a risk-based strategy, a screening-based strategy, a combined screening/risk-based strategy and the current Dutch guideline. Design Cost-effectiveness analysis based on decision model. Setting Obstetric care system in the Netherlands. Population/Sample Hypothetical cohort of 200,000 neonates. Methods A decision analysis model was used to compare the costs and effects of different treatment strategies with no treatment. Baseline estimates were derived from literature and a survey among parents of children affected by GBS disease. The analysis was performed from a societal perspective, and costs and effects were discounted at a percentage of 3%. Main outcome measures Cost per quality adjusted of life-year (QALY). Result The risk-based strategy will prevent 352 cases of early-onset GBS for ,5.0 million, indicating a cost-effectiveness ratio of ,7600 per QALY gained. The combined screening risk-based strategy has comparable results. The current Dutch guideline resulted in lower effects for higher costs. The screening-based strategy shows the highest reduction in cases of early-onset GBS, however, at a cost-effectiveness ratio of ,59,300 per QALY gained. Introducing the polymerase chain reaction (PCR) test may lead to a more favourable cost-effectiveness ratio. Conclusion In the Dutch system, the combined screening/risk-based strategy and the risk-based strategy have reasonable cost-effectiveness ratios. If it becomes feasible to add the PCR test, the cost-effectiveness of the combined screening/risk-based strategy may even be more favourable. [source] A cost-effectiveness analysis of four management strategies in the determination and follow-up of atypical squamous cells of undetermined significanceDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2005Alice A. Hughes M.S.P.H. Abstract Atypical squamous cells of undetermined significance (ASC-US) are the most common abnormal cytological result on Papanicolaou (Pap) smear. We analyzed four management strategies in a hypothetical cohort of women divided by age group: (1) immediate colposcopy, (2) repeat cytology after an ASC-US Pap smear result, (3) conventional Pap with reflex human papillomavirus (HPV) testing, and (4) liquid-based cytology with reflex HPV testing. Parameter variables were collected from previously published data. Strategies that included reflex HPV testing had the lowest overall costs for all age groups combined. Repeat Pap smears had the highest number of true positive results throughout all stages but also had the uppermost number of missed cancers and highest costs. Immediate colposcopy had the second highest overall costs and detected fewer true positive results than liquid-based cytology. Younger women (aged 18,24 yr) consistently had higher total costs for all strategies investigated. Using the incremental cost-effectiveness (CE) ratio, the immediate colposcopy strategy was more costly and less effective than liquid-based cytology and, therefore, was dominated. The incremental CE ratio was lowest for liquid-based cytology compared with conventional cytology and liquid-based cytology with reflex HPV testing was the most cost-effective strategy. Diagn. Cytopathol. 2005;32:125,132. © 2005 Wiley-Liss, Inc. [source] Is Defibrillation Testing Still Necessary?JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2008A Decision Analysis, Markov Model Objective: To assess the impact of defibrillation threshold (DFT) testing of implanted cardioverter-defibrillators (ICDs) on survival. Background: DFT testing is generally performed during implantation of ICDs to assess sensing and termination of ventricular fibrillation. It is common clinical practice to defibrillate ventricular fibrillation twice at an output at least 10 J below the maximum output of the device, providing a 10 J safety margin. However, there are few data regarding impact of DFT testing on outcomes. Methods: Decision analysis and Monte Carlo simulation were used to assess expected outcomes of DFT testing. Survival of a hypothetical cohort of patients was assessed according to two strategies,routine DFT testing at time of ICD implant versus no DFT testing. Assumptions in the model were varied over a range of reasonable values to assess outcomes under a variety of scenarios. Results: Five-year survival with DFT and no-DFT strategies were similar at 59.72% and 59.36%, respectively. The results were not sensitive to changing risk estimates for arrhythmia incidence and safety margin. Results of the Monte Carlo simulation were qualitatively similar to the base case scenario and consistent with a small and nonsignificant survival advantage with routine DFT testing. Conclusions: The impact of DFT testing on 5-year survival in ICD patients, if it exists, is small. Survival appears higher with DFT testing as long as annual risk of lethal arrhythmia or the risk of a narrow safety margin is at least 5%, although the incremental benefit is marginal and 95% confidence intervals cross zero. A prospective randomized study of DFT testing in modern devices is warranted. [source] Screening for Wilms tumor and hepatoblastoma in children with Beckwith-Wiedemann syndromes: A cost-effective model,PEDIATRIC BLOOD & CANCER, Issue 4 2001D. Elizabeth McNeil MD Abstract Background We undertook a cost-benefit analysis of screening for Wilms tumor and hepatoblastoma in children with Beckwith-Wiedemann syndrome (BWS), a known cancer predisposition syndrome. The purpose of this analysis was twofold: first, to assess whether screening in children with BWS has the potential to be cost-effective; second, if screening appears to be cost-effective, to determine which parameters would be most important to assess if a screening trial were initiated. Procedures We used data from the BWS registry at the National Cancer Institute, the National Wilms Tumor Study (NWTS), and large published series to model events for two hypothetical cohorts of 1,000 infants born with BWS. One hypothetical cohort was screened for cancer until a predetermined age, representing the base case. The other cohort was unscreened. For our base case, we assumed: (a) sonography examinations three times yearly (triannually) from birth until 7 years of age; (b) screening would result in one stage shift downward at diagnosis for Wilms tumor and hepatoblastoma; (c) 100% sensitivity and 95% specificity for detecting clinical stage I Wilms tumor and hepatoblastoma; (d) a 3% discount rate; (e) a false positive result cost of $402. We estimated mortality rates based on published Wilms tumor and hepatoblastoma stage specific survival. Results Using the base case, screening a child with BWS from birth until 4 years of age results in a cost per life year saved of $9,642 while continuing until 7 years of age results in a cost per life-year saved of $14,740. When variables such as cost of screening examination, discount rate, and effectiveness of screening were varied based on high and low estimates, the incremental cost per life-year saved for screening up until age four remained comparable to acceptable population based cancer screening ranges (<,$50,000 per life year saved). Conclusions Under our model's assumptions, abdominal sonography examinations in children with BWS represent a reasonable strategy for a cancer screening program. A cancer screening trial is warranted to determine if, when, and how often children with BWS should be screened and to determine cost-effectiveness in clinical practice. Med Pediatr Oncol 2001;37:349,356. Published 2001 Wiley-Liss, Inc. [source] Informing policy for the Australian context , Costs, outcomes and cost savings of prenatal carrier screening for cystic fibrosisAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2010Susannah MAXWELL Aims:, To examine the costs, outcomes and cost savings of three models of prenatal cystic fibrosis (CF) carrier screening compared to no screening from a public health sector perspective. Methods:, A decision tree was generated to estimate costs and outcomes for each screening model for a hypothetical cohort of 38 000 pregnancies. Sensitivity analysis assessed the impact of model parameter variation. Results:, Under baseline assumptions, the initial annual cost to provide a prenatal CF carrier-screening programme is Au$5.32 million, Au$3.35 million and $2.93 million for one-step, two-step simultaneous and two-step sequential screening respectively. Annual costs are significantly lower for an established programme. No screening model provides a net saving over a lifetime horizon; however, the results were sensitive to variation in lifetime cost of care, screening test costs and number of pregnancies per carrier couple. Conclusions:, Under some scenarios, prenatal CF carrier screening is cost saving to the health system; however, this is not conclusive and depends on several factors. Cost remains a potential barrier due to the substantial level of funding required in the short term. Feasibility and psychosocial, ethical and legal implications of screening need to be considered. Additionally, consultation is required with the Australian community on the acceptability and/or desire for prenatal CF carrier screening. [source] Modelling the potential impact of population-wide periconceptional folate/multivitamin supplementation on multiple birthsBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 9 2001Judith Lumley Objective To develop a model of the impact of population-wide periconceptional folate supplementation on neural tube defects and twin births. Design A hypothetical cohort of 100,000 pregnancies ,20 weeks, plus terminations of pregnancy after prenatal diagnosis before 20 weeks. Methods Application of pooled data on the relative risks for neural tube defects and twins following periconceptional folate from meta-analysis of the randomised trials. Main outcome measures 1. Pregnancies with a neural tube defect (i.e. terminations of pregnancy, perinatal deaths, and surviving infants); 2. twin births (i.e. preterm births, perinatal deaths, postneonatal deaths, birth defects, cerebral palsy); 3. numbers needed to treat. Results The change in neural tube defects would be 75 fewer terminations (95% CI -47, -90), 30 fewer perinatal deaths (95% CI 18, -35), and 13 fewer surviving infants with a neural tube defect (95% CI ,8, -16). The change in twinning would be an additional 572 twin confinements (95% CI ,100, +1587), among whom there would be 63 very preterm twin confinements (95% CI ,11, +174), 54 perinatal and postneonatal deaths (95% CI ,9, +149), 48 surviving twins with a birth defect (95% CI ,8, +133), and nine with cerebral palsy (95% CI ,2, +26). The numbers needed to treat for the prevention of one pregnancy with a neural tube defect is 847, for the birth of one additional set of twins is 175, for the birth of one additional set of very preterm twins is 1587, and for the birth of an additional twin with any of the following outcomes (perinatal death, postneonatal death, survival with a birth defect, or survival with cerebral palsy) is 901. Conclusions Monitoring rates of neural tube defects and twinning is essential as supplementation or fortification with folate is implemented. [source] Role of chemotherapy for patients with recurrent platinum-resistant advanced epithelial ovarian cancer,CANCER, Issue 3 2006A cost-effectiveness analysis Abstract BACKGROUND. Current chemotherapy in platinum-resistant ovarian cancer patients has demonstrated minimal to no improvements in survival. Despite the lack of benefit, significant resources are utilized with such therapies. Therefore, the objective in the current study was to assess the cost-effectiveness of salvage chemotherapy for patients with platinum-resistant epithelial ovarian cancer (EOC). METHODS. A decision analysis model evaluated a hypothetical cohort of 4000 platinum-resistant patients with recurrent EOC. Several chemotherapy strategies were analyzed: 1) best supportive care (BSC); 2) second-line chemotherapy-monotherapy; 3) second-line chemotherapy-combination therapy; 4) third-line chemotherapy after disease progression on second-line monotherapy; and 5) third-line chemotherapy after disease progression on second-line combination therapy. Sensitivity analyses were performed on all pertinent uncertainties. RESULTS. Using costs alone, BSC was the only definitive cost-effective treatment for platinum-resistant recurrent ovarian cancer patients, and second-line monotherapy was a reasonable cost-effective strategy with an incremental cost-effectiveness ratio (ICER) of $64,104. The cost-effectiveness ranged from $4,065 per month of overall survival (OS) for BSC to $12,927 for third-line previous combination therapy. Compared with BSC, second-line monotherapy gained an additional 3 months of OS, with a cost-effectiveness of $4,703 per month of OS. Second-line combination therapy and third-line therapies exhibited unfavorable ICER. CONCLUSIONS. The current decision analysis was intended to be thought-provoking and bring awareness to the high costs of subsequent chemotherapy with limited effectiveness in patients with recurrent platinum-resistant EOC. Although actual patients may receive multiple lines of chemotherapy, from the perspective of costs alone this model using a hypothetical cohort demonstrated that best supportive care was the only cost-effective strategy, with second-line monotherapy appearing to be a reasonable cost-effective strategy given current chemotherapeutic options. Cancer 2006. © 2006 American Cancer Society. [source] Cost-effectiveness analysis of screening modalities for breast cancer in Japan with special reference to women aged 40,49 yearsCANCER SCIENCE, Issue 11 2006Koji Ohnuki Although the introduction of screening mammography in Japan would be expected to reduce mortality from breast cancer, the optimal screening modality in terms of cost-effectiveness remains unclear. We compared the cost-effectiveness ratio, defined as the cost required for a life-year saved, among the following three strategies: (1) annual clinical breast examination; (2) annual clinical breast examination combined with mammography; and (3) biennial clinical breast examination combined with mammography for women aged 30,79 years using a hypothetical cohort of 100 000. The sensitivity, specificity and early breast cancer rates were derived from studies conducted from 1995 to 2000 in Miyagi Prefecture. The treatment costs were based on a questionnaire survey conducted at 13 institutions in Japan. We used updated parameters that were needed in the analysis. Although the effectiveness of treatment in terms of the number of expected survival years was highest for annual combined modality, biennial combined modality had a higher cost-effectiveness ratio, followed by annual combined modality and annual clinical breast examination in all age groups. In women aged 40,49 years, annual combined modality saved 852.9 lives and the cost/survival duration was 3 394 300 yen/year, whereas for biennial combined modality the corresponding figures were 833.8 and 2 025 100 yen/year, respectively. Annual clinical breast examination did not confer any advantages in terms of effectiveness (815.5 lives saved) or cost-effectiveness (3 669 900 yen/year). While the annual combined modality was the most effective with respect to life-years saved among women aged 40,49 years, biennial combined modality was found to provide the highest cost-effectiveness. (Cancer Sci 2006; 97: 1242,1247) [source] Predicting the probability of progression-free survival in patients with small hepatocellular carcinomaLIVER TRANSPLANTATION, Issue 4 2002Steve J. Cheng Allocation of cadaveric livers to patients based on such objective medical urgency data as the Model for End-Stage Liver Disease (MELD) score may not benefit patients with small hepatocellular carcinomas (HCCs). To ensure that these patients have a fair opportunity of receiving a cadaveric organ, the risk for death caused by HCC and tumor progression beyond 5 cm should be considered. Using a Markov model, two hypothetical cohorts of patients with small hepatomas were assumed to have either (1) Gompertzian tumor growth, in which initial exponential growth decreases as tumor size increases; or (2) rapid exponential growth. The model tracked the number of patients who either died or had tumor progression beyond 5 cm. These results were used to back-calculate an equivalent MELD score for patients with small HCCs. All probabilities in the model were varied simultaneously using a Monte Carlo simulation. The Gompertzian growth model predicted that patients with a 1- and 4-cm tumor have 1-year progression-free survival rates of 70% (HCC-specific MELD score 6) and 66% (HCC-specific MELD score 8), respectively. When assuming rapid exponential growth, patients with a 1- and 4-cm tumor have progression-free survival rates of 69% (HCC-specific MELD score 6) and 12% (HCC-specific MELD score 24), respectively. Our model predicted that the risk for death caused by HCC or tumor progression beyond 5 cm should increase with larger initial tumor size in patients with small hepatomas. To ensure that these patients have a fair opportunity to receive a cadaveric organ, HCC-specific scores predicted by our model could be added to MELD scores of patients with HCC. [source] Screening for Wilms tumor and hepatoblastoma in children with Beckwith-Wiedemann syndromes: A cost-effective model,PEDIATRIC BLOOD & CANCER, Issue 4 2001D. Elizabeth McNeil MD Abstract Background We undertook a cost-benefit analysis of screening for Wilms tumor and hepatoblastoma in children with Beckwith-Wiedemann syndrome (BWS), a known cancer predisposition syndrome. The purpose of this analysis was twofold: first, to assess whether screening in children with BWS has the potential to be cost-effective; second, if screening appears to be cost-effective, to determine which parameters would be most important to assess if a screening trial were initiated. Procedures We used data from the BWS registry at the National Cancer Institute, the National Wilms Tumor Study (NWTS), and large published series to model events for two hypothetical cohorts of 1,000 infants born with BWS. One hypothetical cohort was screened for cancer until a predetermined age, representing the base case. The other cohort was unscreened. For our base case, we assumed: (a) sonography examinations three times yearly (triannually) from birth until 7 years of age; (b) screening would result in one stage shift downward at diagnosis for Wilms tumor and hepatoblastoma; (c) 100% sensitivity and 95% specificity for detecting clinical stage I Wilms tumor and hepatoblastoma; (d) a 3% discount rate; (e) a false positive result cost of $402. We estimated mortality rates based on published Wilms tumor and hepatoblastoma stage specific survival. Results Using the base case, screening a child with BWS from birth until 4 years of age results in a cost per life year saved of $9,642 while continuing until 7 years of age results in a cost per life-year saved of $14,740. When variables such as cost of screening examination, discount rate, and effectiveness of screening were varied based on high and low estimates, the incremental cost per life-year saved for screening up until age four remained comparable to acceptable population based cancer screening ranges (<,$50,000 per life year saved). Conclusions Under our model's assumptions, abdominal sonography examinations in children with BWS represent a reasonable strategy for a cancer screening program. A cancer screening trial is warranted to determine if, when, and how often children with BWS should be screened and to determine cost-effectiveness in clinical practice. Med Pediatr Oncol 2001;37:349,356. Published 2001 Wiley-Liss, Inc. [source] Management of patients with acoustic neuromas: A Markov decision analysis,THE LARYNGOSCOPE, Issue 4 2010Daniel Morrison MD Abstract Objectives/Hypothesis: The management of patients with small (<1.5 cm) acoustic neuromas is controversial. Immediate treatment via microsurgical resection or radiosurgery is often advocated. A period of observation is sometimes advised followed by microsurgery or radiosurgery for tumors that demonstrate growth during the observation period. The purpose of this study is to calculate quality-adjusted life expectancy for the most commonly applied management strategies in hypothetical cohorts of patients of various ages. Study Design: Markov decision analysis; societal perspective. Methods: Assumptions used in creating this model and event probabilities were obtained from a thorough literature review. Key parameters were identified and defined by the best available evidence. The main outcome measure is the benefit derived from each management strategy in quality-adjusted life years (QALYs). Sensitivity analysis was used to define benchmark performance information for these parameters. Results: The benefit of a period of observation followed by radiosurgery, if needed, for significant tumor growth is greater then all other strategies for all age groups and both sexes. When compared to observation followed by microsurgery, the additional benefit is small. QALY totals for the two immediate treatment groups were significantly lower than that for the observation groups. Conclusions: For patients of all ages, a period of observation during which tumor growth and hearing thresholds are closely monitored is the superior strategy. For tumors that grow substantially or when hearing deteriorates, definitive management via radiosurgery is recommended. Laryngoscope, 2010 [source] | ||||||||||||||||||||||