Causality and Association: The Statistical and Legal Approaches

This paper discusses different needs and approaches to establishing ``causation'' that are relevant in legal cases involving statistical input based on epidemiological (or more generally observational or population-based) information. We distinguish between three versions of ``cause'': the first involves negligence in providing or allowing exposure, the second involves ``cause'' as it is shown through a scientifically proved increased risk of an outcome from the exposure in a population, and the third considers ``cause'' as it might apply to an individual plaintiff based on the first two. The population-oriented ``cause'' is that commonly addressed by statisticians, and we propose a variation on the Bradford Hill approach to testing such causality in an observational framework, and discuss how such a systematic series of tests might be considered in a legal context. We review some current legal approaches to using probabilistic statements, and link these with the scientific methodology as developed here. In particular, we provide an approach both to the idea of individual outcomes being caused on a balance of probabilities, and to the idea of material contribution to such outcomes. Statistical terminology and legal usage of terms such as ``proof on the balance of probabilities'' or ``causation'' can easily become confused, largely due to similar language describing dissimilar concepts; we conclude, however, that a careful analysis can identify and separate those areas in which a legal decision alone is required and those areas in which scientific approaches are useful.Comment: Published in at http://dx.doi.org/10.1214/07-STS234 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Stroke mimic diagnoses presenting to a hyperacute stroke unit.

Stroke services have been centralised in several countries in recent years. Diagnosing acute stroke is challenging and a high proportion of patients admitted to stroke units are diagnosed as a non-stroke condition (stroke mimics). This study aims to describe the stroke mimic patient group, including their impact on stroke services. We analysed routine clinical data from 2,305 consecutive admissions to a stroke unit at St George's Hospital, London. Mimic groupings were derived from 335 individual codes into 17 groupings. From 2,305 admissions, 555 stroke mimic diagnoses were identified (24.2%) and 72% of stroke mimics had at least one stroke risk factor. Common mimic diagnoses were headache, seizure and syncope. Medically unexplained symptoms and decompensation of underlying conditions were also common. Median length of stay was 1 day; a diagnosis of dementia (p=0.028) or needing MRI (p=0.006) was associated with a longer stay. Despite emergency department assessment by specialist clinicians and computed tomography brain, one in four suspected stroke patients admitted to hospital had a non-stroke diagnosis. Stroke mimics represent a heterogeneous patient group with significant impacts on stroke services. Co-location of stroke and acute neurology services may offer advantages where service reorganisation is being considered

The Nature of the New Employment Relationship(s): A Content Analysis of the Practitioner and Academic Literatures

This article seeks to provide HRM professionals information and guidance that will assist them in understanding, evaluating, and applying current thinking regarding the new employment relationship. The focus of the article is a study that investigates the extent to which there is a consensus in the literature regarding the nature of the new employment relationship by systematically analyzing the content of relevant articles. The discussion incorporates empirical findings from other studies, notes differences between the articles found in scholarly publications versus those found in trade magazines, provides recommendations for HRM professionals, and suggests areas of future research

An Analysis of Demand-Pull Inflation in the United States Post-Pandemic

The COVID-19 pandemic led to a global shutdown of the economy resulting from both demand and supply shocks. Also, the significant decline in output and employment in the immediate aftermath of the pandemic led to a fast reaction from the government in the form of large fiscal rescue packages. At the end of 2021, the acceleration of inflation, which had been dormant for more than four decades, became the main topic of macroeconomic debates. The debate has revolved around the influence of cost-push versus demand-pull causes of inflation. The dominant view in the United States has been that inflation resulted from excess demand and an overreaction of the Federal Reserve and the Treasury in stimulating the economy. Accordingly, the Federal Reserve has continued to fight inflation by employing tight monetary policy and raising interest rates to reduce demand. However, inflation has persisted, and it seems that monetary tightening might not be an adequate solution, as it appears we are not at full employment nor full capacity utilization. Therefore, inflation is not the result of excess demand. The persistence of inflation seems to be resulting from the continuing supply-side problems and shutdowns that disrupted global trade

Air data measurement system for space shuttle

It is concluded that air data measurements of angle of attack and sideslip are needed to control the space shuttle vehicles. The basis for this conclusion, along with recommended sensor design and implementation, are described

Direction of copper phthalocyanine crystallization using in situ generated tethered phthalocyanines

Copper phthalocyanine in the metastable α crystal polymorph can be obtained directly from phthalonitrile or from phthalodiimide, which would normally give the more stable β crystal form, by the inclusion of 3% or greater of the sulfide 2 or the diimide 3. The resulting α form material does not revert to the β form upon treatment in boiling xylene, unlike conventionally prepared α copper phthalocyanine

Determination of solid mass fraction in partially frozen hydrocarbon fuels

Filtration procedures alone are insufficient to determine the amounts of crystalline solid in a partially frozen hydrocarbon distillate fraction. This is due to the nature of the solidification process by which a large amount of liquid becomes entrapped within an interconnected crystalline structure. A technique has been developed to supplement filtration methods with an independent determination of the amount of liquid in the precipitate thereby revealing the actual value of mass percent crystalline solid, %S. A non-crystallizing dye is injected into the fuel and used as a tracer during the filtration. The relative concentrations of the dye in the filtrate and precipitate fractions is subsequently detected by a spectrophotometric comparison. The filtration apparatus was assembled so that the temperature of the sample is recorded immediately above the filter. Also, a second method of calculation has been established which allows significant reduction in test time while retaining acceptable accuracy of results. Data have been obtained for eight different kerosene range hydrocarbon fuels

Impurity occurrence and removal in crystalline products from process reactions

The behavior of impurities when subjected to crystallizations, and related processes such as recrystallization and reslurrying, has been reviewed with a particular focus on the years 2000–2015, but also including significant cases from outside that period. Small molecule pharmaceuticals and similar small organic molecules are included but not biomolecules, inorganics, or minerals. Phase impurities are only covered when a phase transformation is involved with the management of an impurity. Introductory examples illustrating some general features of crystallization as a method of purification are presented, as well as approaches to quantifying the effectiveness of purification. The review classifies cases based on the behavior of the specific impurities covered. The classes of behavior observed are the removal by washing, recrystallization, or reslurrying (Class I), impurities not being removed by these operations (Class II), and impurities which are removed in conjunction with a phase transformation (Class III). Examples of each of these types of behavior are presented, with many processes producing impurities which fall into more than one of these classes. Studies on the inclusion of extraneous molecules into crystalline materials are also covered. These particularly include the incorporation of compounds as solid solutions, but also eutectic formation and inclusion at surfaces during crystal growth. The relationship between types of impurities and behavior during processing is also examined

A cross-sectional analysis of pharmaceutical industry-funded events for health professionals in Australia

Objectives: To analyse patterns and characteristics of pharmaceutical industry sponsorship of events for Australian health professionals and to understand the implications of recent changes in transparency provisions that no longer require reporting of payments for food and beverages. Design: Cross-sectional analysis. Participants and setting: 301 publicly available company transparency reports downloaded from the website of Medicines Australia, the pharmaceutical industry trade association, covering the period from October 2011 to September 2015. Results: Forty-two companies sponsored 116 845 events for health professionals, on average 608 per week with 30 attendees per event. Events typically included a broad range of health professionals: 82.0% included medical doctors, including specialists and primary care doctors, and 38.3% trainees. Oncology, surgery and endocrinology were the most frequent clinical areas of focus. Most events (64.2%) were held in a clinical setting. The median cost per event was $A263 (IQR$A153–1195) and over 90% included food and beverages. Conclusions: Over this 4-year period, industry-sponsored events were widespread and pharmaceutical companies maintained a high frequency of contact with health professionals. Most events were held in clinical settings, suggesting a pervasive commercial presence in everyday clinical practice. Food and beverages, known to be associated with changes to prescribing practice, were almost always provided. New Australian transparency provisions explicitly exclude meals from the reporting requirements; thus, a large proportion of potentially influential payments from pharmaceutical companies to health professionals will disappear from public view