A Comparison of Large-Sample Confidence Interval Methods for the Difference of Two Binomial Probabilities

A simulation study was done to compare seven confidence interval methods, based on the normal approximation, for the difference of two binomial probabilities. Cases considered included minimum expected cell sizes ranging from 2 to 15 and smallest group sizes (NMIN) ranging from 6 to 100. Our recommendation is to use a continuity correction of 1/(2 NMIN) combined with the use of (N ? 1) rather than N in the estimate of the standard error. For all of the cases considered with minimum expected cell size of at least 3, this method gave coverage probabilities close to or greater than the nominal 90% and 95%. The Yates method is also acceptable, but it is slightly more conservative. At the other extreme, the usual method (with no continuity correction) does not provide adequate coverage even at the larger sample sizes. For the 99% intervals, our recommended method and the Yates correction performed equally well and are reasonable for minimum expected cell sizes of at least 5. None of the methods performed consistently well for a minimum expected cell size of 2.     

Consideration of the Aerosol Transmission for COVID-19 and Public Health

This article analyzes the available evidence to address airborne, aerosol transmission of the SARS-CoV-2. We review and present three lines of evidence: case reports of transmission for asymptomatic individuals in association with studies that show that normal breathing and talking produce predominantly small droplets of the size that are subject to aerosol transport; limited empirical data that have recorded aerosolized SARS-CoV-2 particles that remain suspended in the air for hours and are subject to transport over distances including outside of rooms and intrabuilding, and the broader literature that further supports the importance of aerosol transmission of infectious diseases. The weight of the available evidence warrants immediate attention to address the significance of aerosols and implications for public health protection.     

Assessing Statistical Results: Magnitude,Precision, and Model Uncertainty

ABSTRACT

Evaluating the importance and the strength of empirical evidence requires asking three questions: First, what are the practical implications of the findings? Second, how precise are the estimates? Confidence intervals provide an intuitive way to communicate precision. Although nontechnical audiences often misinterpret confidence intervals (CIs), I argue that the result is less dangerous than the misunderstandings that arise from hypothesis tests. Third, is the model correctly specified? The validity of point estimates and CIs depends on the soundness of the underlying model.     

Understanding the Ecological Validity of Relying Practice as a Basis for Risk Identification

Understanding the reliability of hazardous organizations and their protective systems is central to understanding the risk they produce. Work on “high reliability organization” has done much to illuminate the conditions in which social organization becomes reliable in highly demanding conditions. But risk depends just as much on how relying entities do their relying as it does on the reliability of the entities they rely on. Patterns of relying are often opaque in sociotechnical systems, and processes of relying and being relied on are mutually influencing in complex ways, so the relationship between relying and risk may not be at all obvious. This study was an attempt to study relying as a social practice, in particular analyzing how it had ecological validity in a social organization—how practice was responsive to the conditions in which it took place. This involved observational fieldwork and inductive, qualitative analysis on an offshore oil and gas production platform that was nearing the end of its design life and undergoing refurbishment. The analysis produced four main categories of ecological validity: responsiveness to formal organization, responsiveness to situational contingency, responsiveness to information asymmetry, and responsiveness to sociomateriality. This ecological validity of relying practice should be a primary focus of risk identification, assessing how relying can become mismatched to reliability in certain ways, both when relying practice is responsive to circumstances and when it is not.     

Pressure to Attend Therapy,Dyadic Adjustment,and Adverse Childhood Experiences: Direct and Indirect Effects on the Therapeutic Alliance in Couples Therapy

In this study we examine the role that pressure to attend therapy, dyadic adjustment, and adverse childhood experiences (ACEs) play in developing the therapeutic alliance. A total of 351 couples received treatment as usual at three family therapy training clinics. Participants rated predictor variables at intake and alliance at the fourth session. Results of a path analysis indicate that each partner's dyadic adjustment is directly associated with the quality of her or his own alliance. In addition, when male partners report more ACEs and pressure to attend treatment, their own alliance scores decrease. Additionally, when one partner reports feeling pressure to attend therapy, the other partner's alliance decreases. Finally, for males, there is an indirect effect of dyadic adjustment on alliance through pressure to attend therapy. These results suggest that clinicians should routinely assess relationship adjustment, how pressured each partner is feeling to attend treatment, and ACEs; as these may impact alliance quality.     

Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book

Six multi‐decade‐long members of SRA reflect on the 1983 Red Book in order to examine the evolving relationship between risk assessment and risk management; the diffusion of risk assessment practice to risk areas such as homeland security and transportation; the quality of chemical risk databases; challenges from other groups to elements at the core of risk assessment practice; and our collective efforts to communicate risk assessment to a diverse set of critical groups that do not understand risk, risk assessment, or many other risk‐related issues. The authors reflect on the 10 recommendations in the Red Book and present several pressing challenges for risk assessment practitioners.     

Reflections of an ordinary life

Philip Anderson (not his real name) was one of thirty people who talked to Wendy Booth and Tim Booth as part of their recently published study Growing Up with Parents who have Learning Difficulties (London: Routledge, 1998). Philip's stoy illustrates many of the themes common to the experience of this group: resilience in the face of risk; the importance of family, especially grandma; social exclusion; the effects of hardship; and the enduring nature of parent-child bonds.     

Fertility decline in Scotland, England and Wales, and Ireland: comparisons from the 1911 census of fertility

Data on family size by year of marriage, age at marriage, and duration of marriage, from the 1911 Fertility Census, are compared between Scotland, England and Wales, Irish county boroughs, and the rest of Ireland. While means show significant inter-country differences, from the 1880s marked similarities are found across all the countries in the pattern of fertility decline, strongly suggesting significant fertility limitation in rural Ireland well before 1911. Noting the implications for the use of rural Ireland as a natural fertility population, the data are instead compared with the Coale-Trussell and Hinde-Woods schedules. The former provides more plausible results, which imply strong period rather than cohort effects in the fertility decline. Except in rural Ireland, little evidence is found for significant fertility limitation early in marriage among younger marrying couples, but many older marrying couples appear to have stopped childbearing at very low parities from an early date.