L’effetto delle operazioni di fusione e acquisizione sui profitti degli azionisti nell’industria farmaceutica

The purpose of this study was to quantify the excess return in shareholder security prices following initial announcements of successful horizontal pharmaceutical mergers which occurred between 1985 and 1996. An event study methodology was used to study a sample of26 fim1s involved in 14 mergers wherein transaction costs exceeded $500 million. Overall, results of the study were consistent with prior research, indicating that target-firm shareholders received a majority oft he short-term merger-related wealth effects in comparison to those received by bidder- firm shareholders

Long-term persistency and costs associated with the use of iron chelation therapies in the treatment of Sickle cell disease within Medicaid programs.

OBJECTIVE: This retrospective study evaluated iron chelating therapy (ICT) discontinuation and costs in Sickle cell disease (SCD) Medicaid recipients using healthcare claims from 2006-2010. METHODS: Patients with ≥1 SCD diagnosis claim, ≥2 claims for deferoxamine (DFO) or deferosirox (DFX), and continuous enrollment ≥6 months prior to and 18 months following ICT initiation were included. Outcomes included treatment discontinuation, persistence (i.e., refill gaps ≥6 weeks), and total healthcare costs. RESULTS: The average age among 404 SCD patients meeting study inclusion criteria was 18.7 (±11.0) years, with 45.8% being males and 66.7% being Blacks. Switches or combinations from DFO at index occurred in 124 (74.7%) patients compared to 10 (4.2%) with DFX at index. The Cox regression model that assessed long-term medication persistence indicated a 1.30-times higher likelihood of treatment discontinuation with DFO compared to DFX (95% CI: 1.06-1.61). Some 19.7% of patient remained on DFX relative to 4.8% on DFO. Both inpatient and total costs were similar in DFX and DFO treatment groups. Following 1 year of treatment, 37.4% remained on DFX compared to 15.7% on DFO. Meaningful differences in treatment discontinuation between the two treatment groups did not occur until 220+ days during the study period. At 18-months, treatment discontinuation rates were high in both groups; 95% for DFO and 80% for DFX. CONCLUSION: This study of SCD Medicaid patients found more therapeutic switches from DFO to DFX and a higher medication persistency rate with DFX than DFO. The conclusions are limited by the study\u27s retrospective nature, which depends on multivariate statistics to account for patient heterogeneity and risk factors

The Contrast and Convergence of Bayesian and Frequentist Statistical Approaches in Pharmacoeconomic Analysis

The application of Bayesian statistical analyses has been facilitated in recent years by methodological advances and an increasing complexity necessitated within research. Substantial debate has historically accompanied this analytic approach relative to the frequentist method, which is the predominant statistical ideology employed in clinical studies. While the essence of the debate between the two branches of statistics centres on differences in the use of prior information and the definition of probability, the ramifications involve the breadth of research design, analysis and interpretation. The purpose of this paper is to discuss the application of frequentist and Bayesian statistics in the pharmacoeconomic assessment of healthcare technology. A description of both paradigms is offered in the context of potential advantages and disadvantages, and applications within pharmacoeconomics are briefly addressed. Additional considerations are presented to stimulate further development and to direct appropriate applications of each method such that the integrity and robustness of scientific inference be strengthened.Bayesian-analysis, Cost-effectiveness, Pharmacoeconomics, Statistics

Increased Statistical Efficiency in a Lognormal Mean Model

Within the context of clinical and other scientific research, a substantial need exists for an accurate determination of the point estimate in a lognormal mean model, given that highly skewed data are often present. As such, logarithmic transformations are often advocated to achieve the assumptions of parametric statistical inference. Despite this, existing approaches that utilize only a sample’s mean and variance may not necessarily yield the most efficient estimator. The current investigation developed and tested an improved efficient point estimator for a lognormal mean by capturing more complete information via the sample’s coefficient of variation. Results of an empirical simulation study across varying sample sizes and population standard deviations indicated relative improvements in efficiency of up to 129.47 percent compared to the usual maximum likelihood estimator and up to 21.33 absolute percentage points above the efficient estimator presented by Shen and colleagues (2006). The relative efficiency of the proposed estimator increased particularly as a function of decreasing sample size and increasing population standard deviation

An Estimation Error Corrected Sharpe Ratio Using Bootstrap Resampling

Abstract The Sharpe ratio is a common financial performance measure that represents the optimal risk versus return of an investment portfolio, also defined as the slope of the capital market line within the mean-variance Markowitz efficient frontier. Obtaining sample point and confidence interval estimates for this metric is challenging due to both its dynamic nature and issues surrounding its statistical properties. Given the importance of obtaining robust determinations of risk versus return within financial portfolios, the purpose of the current research was to improve the statistical estimation error associated with Sharpe's ratio, offering an approach to point and confidence interval estimation which employs bootstrap resampling and computational intelligence. This work also extends prior studies by minimizing the ratio's statistical estimation error first by incorporating the common assumption that the ratio's loss function is the squared error and second by correcting for overestimation through an approach that recognizes that th

The Assessment of Clinical and Economic Outcomes Associated with Stroke in Rural Emergency Departments

Class of 2013 AbstractSpecific Aims: The purpose of this study was to assess the clinical and economic predictors associated with rural emergency department visits in stroke patients. Methods: The current research was a retrospective, observational, cohort study. Multivariate regression was used to assess data from the Agency for Healthcare Research and Quality (AHRQ) 2009 Nationwide Emergency Department Sample (NEDS). Inclusion criteria were at least 18 years of age and rural ED admission with principle diagnoses of stroke. Main Results: Significant results for risks included: Intubation for increased mortality (OR = 17.432, p = 0.001), increased length of stay (IRR = 1.643, p = 0.018) and increased charges (exp β = 2.289, p = < 0.001); myocardial infarction for increased mortality (OR = 1.969, p = 0.006), decreased charges (exp β = 0.862, p = 0.013) and decreased length of stay (IRR = 0.853, p = 0.001); moderate to severe liver disease for increased mortality (OR = 62.691, p = 0.001) and reduced length of stay (IRR = 0.517, p = 0.025); congestive heart failure for increased mortality (OR 1.978, p = 0.003) and increased charges (exp β = 1.118, p = 0.039); non-specific cancer (OR = 2.447, p = 0.017) and metastatic cancer (OR = 4.799, p = 0.016) for mortality; hemiplegia/paraplegia for increased charges (exp β = 1.173, p = < 0.001). Conclusion: The current study found a better understanding of national estimates of burden of illness to further define clinical decision rules for stroke in rural emergency departments.This item is part of the Pharmacy Student Research Projects collection, made available by the College of Pharmacy and the University Libraries at the University of Arizona. For more information about items in this collection, please contact Jennifer Martin, Librarian and Clinical Instructor, Pharmacy Practice and Science, [email protected]

A Diabetic Emergency One Million Feet Long: Disparities and Burdens of Illness among Diabetic Foot Ulcer Cases within Emergency Departments in the United States, 2006-2010.

To evaluate the magnitude and impact of diabetic foot ulcers (DFUs) in emergency department (ED) settings from 2006-2010 in the United States (US).This cross-sectional study utilized Agency for Healthcare Research and Quality (AHRQ) Healthcare Cost and Utilization Project (HCUP) National Emergency Department Sample (NEDS) discharge records of ED cases among persons ≥18 years with any-listed diagnosis of DFUs. Multivariable analyses were conducted for clinical outcomes of patient disposition from the ED and economic outcomes of charges and lengths of stay based upon patient demographic and socioeconomic factors, hospital characteristics, and comorbid disease states.Overall, 1,019,861 cases of diabetic foot complications presented to EDs in the US from 2006-2010, comprising 1.9% of the 54.2 million total diabetes cases. The mean patient age was 62.5 years and 59.4% were men. The national bill was $1.9 billion per year in the ED and$8.78 billion per year (US$ 2014) including inpatient charges among the 81.2% of cases that were admitted. Clinical outcomes included mortality in 2.0%, sepsis in 9.6% of cases and amputation in 10.5% (major-minor amputation ratio of 0.46). Multivariable analyses found that those residing in non-urban locations were associated with +51.3%, +14.9%, and +41.4% higher odds of major amputation, minor amputation, and inpatient death, respectively (p<0.05). Medicaid beneficiaries incurred +21.1% and +25.1% higher odds for major or minor amputations, respectively, than Medicare patients (p<0.05). Persons within the lowest income quartile regions were associated with a +38.5% higher odds of major amputation (p<0.05) versus the highest income regions.Diabetic foot complications exact a substantial clinical and economic toll in acute care settings, particularly among the rural and working poor. Clear opportunities exist to reduce costs and improve outcomes for this systematically-neglected condition by establishing effective practice paradigms for screening, prevention, and coordinated care