Usual and Shortest Confidence Intervals on Odds Ratios from Logistic Regression

Based on the large-sample normal distribution of the sample log odds ratio and its asymptotic variance from maximum likelihood logistic regression, shortest 95% confidence intervals for the odds ratio are developed. Although the usual confidence interval on the odds ratio is unbiased, the shortest interval is not. That is, while covering the true odds ratio with the stated probability, the shortest interval covers some values below the true odds ratio with higher probability. The upper and lower limits of the shortest interval are shifted to the left of those of the usual interval, with greater shifts in the upper limits. With the log odds model γ + Xβ, in which X is binary, simulation studies showed that the approximate average percent difference in length is 7.4% for n (sample size) = 100, and 3.8% for n = 200. Precise estimates of the covering probabilities of the two types of intervals were obtained from simulation studies, and are compared graphically. For odds ratio estimates greater (less) than one, shortest intervals are more (less) likely to include one than are the usual intervals. The usual intervals are likelihood-based and the shortest intervals are not. The usual intervals have minimum expected length among the class of unbiased intervals. Shortest intervals do not provide important advantages over the usual intervals, which we recommend for practical use.     

How the Reflection of Linear Correlation in Odds Ratios Depends on the Cut-Off Points

When an OR is calculated based on data measured on continuous scales, the magnitude of the OR is dependent on the cut-offs chosen for dichotomizing both dependent and independent variables even when the relationship is strictly linear. Cuts away from the median on either or both dependent and independent variables increase the expected OR. This increase is quite substantial when the cut-off is made at the extremes. Illustrations of the consequences of cut-off on OR for populations with varying values of linear correlation are provided in simulated and real data. Potential circumstances and motivations for such dichotomizations are discussed.     

A bayesian approach for testing periodicity of dichotomous observations

A Bayesian approach is utilized to test for periodicity in a dichotomous time series. Dichotomous data arise in a variety of circumstances when a variable takes on only two possible values. Conjugate and noninformative priors are considered as well as a hierarchical Bayes approach; the latter is considered the superior Bayes methodology. The situation of stochastic period lengths is also discussed. The generalization to the multinomial model is investigated to allow for the case that a variable takes on more than two possible values. In all cases decisions are made based on a Bayes factor. The proposed procedures are demonstrated on earthquake data in the central Virginia seismic zone     

Use of a single page elder abuse assessment and management tool: a practical clinician's approach to identifying elder mistreatment

Elder abuse is a growing, alarming public health issue. As health care professionals, our challenge is to balance our duty to protect the safety of the vulnerable elder with the elder's right to self-determination. Clinicians in busy practice settings across the continuum of care as well as community-based social workers, emergency medical system, police, and banking personnel are collaborative partners needing tools that focus on early recognition, assessment, intervention, and management of elder abuse. A simple one-page tool that provides principles of assessment and management, best practice guidelines and screening questions will hopefully serve to raise awareness of this important public health issue and maintain a high index of suspicion for elder abuse, neglect and financial exploitation.     

From the streets to assisted living: perceptions of a vulnerable population

The rapid growth of assisted-living facilities is paralleled by the necessity to understand the needs of the people living in them. A hallmark challenge for individuals who are poor and disabled, and often marginalized from mainstream society, is maintaining integrity and being a whole person, rather than a sum of broken parts. A key to maintaining this integrity is the ability to find stable housing and support systems. The inner-city assisted-living facility in this study is unique in that all of its residents are funded by Medicaid. The residents have complex needs related to histories of homelessness, mental illness, drug and/or alcohol addiction, and chronic illness. The purpose of this study was to explore the needs of this vulnerable population as they adapt to a new home and a new concept of assisted, yet independent, living. Structured interviews with key informants and oral survey questionnaires with residents provided quantitative and qualitative data about physical and mental health status, social support, perception of control, psychological wellbeing, and life satisfaction. This study provided valuable insights into the challenges inherent in providing a high quality of life in assisted living for a vulnerable population with diverse needs.     

Applications of a Capability approach to disability and the International Classification of Functioning, Disability and Health (ICF) in social work practice

As disability rates increase more social workers will require greater preparation to practice effectively with individuals with disabilities. The Capability approach and the International Classification of Functioning, Disability and Health provide helpful tools for social worker training. The capability approach emphasizes the need to assess what individuals are able to do in their real-life environments (capabilities) rather than capacity or functional status. The ICF provides helpful disability-related terminology and an actual classification to assist social workers to develop appropriate interventions that facilitate capability development among individuals with disabilities. Using the capability framework with the ICF will contribute to improved understanding of disability among social work students and practitioners.     

The self reported confidence of newly graduated midwives before and after their first year of practice in Sydney, Australia

BackgroundGraduates from a new, 3-year Bachelor of Midwifery program joined those educated through the 1 year, postgraduate route (for those already qualified as nurses) for the first time in New South Wales (NSW) Australia in 2007. Many hospitals offer transition support programs for new graduates during their first year of practice though there is little evidence available to inform these programs.ObjectivesTo establish the new midwife's confidence in working to the 14 “National Competency Standards for the Midwife”¹ and the International Confederation of Midwives (ICM) Definition of a Midwife and to explore whether the new midwife's confidence changed over the new graduate year. In particular the study set out to determine whether there were any differences in the confidence of new graduates from undergraduate or postgraduate programs.DesignPre and post survey with comparisons longitudinally and within undergraduate and postgraduate cohorts.SettingsThree Area Health Services in Sydney and surrounding areas, Australia.ParticipantsA convenience sample of all new graduate midwives employed in the three Area Health Services in the early months of 2008.MethodsNew graduate midwives rated their level of confidence (1–10) in working to the 14 National Competency Standards for the Midwife and the ICM Definition of a Midwife during their first weeks of employment and after the completion of their first year of practice.ResultsMidwives prepared through the undergraduate and postgraduate routes commenced their first year of practice with similar levels of confidence. The confidence of these midwives increased modestly over the first year of practice. Those from postgraduate programs were significantly more confident than those from undergraduate programs on four competencies after the first year of practice. Participant's self reported confidence in working to the ICM Definition of a Midwife was low.ConclusionsOur profession and community need strong, confident midwives and it is in all our interests to look to ways we can best achieve this. While the findings of this study should be treated with caution, this study suggests that there is room for improvement in the way we support newly graduated midwives to build their confidence over their first year of practice. Further research is needed to identify the needs of newly graduated midwives and how best we can support them to develop as strong and confident practitioners through their first year of practice.     

Corporate ownership,efficiency and performance under state capitalism: Evidence from China

This paper studied the relationship between business performance and the ownership structure of firms focusing on Chinese state owned enterprises (SOEs) using a firm level panel data set of China from 1999 to 2011. By classifying all firms into different types based on their ultimate controlling shareholders, we found that SOEs in general underperform in the marketplace than private enterprises. However, among the SOEs in our sample, the SOEs controlled by central government outperformed all types of firms because they offered the highest asset turnover ratio and lowest business administration ratio by receiving favourable government treatment. We conclude that firm ownership type and work efficiency are the main factors that influence the differences in firm performance. In particular, the performance of SOEs controlled by central government is greatly determined by the degree of government intervention, which is referred to as State Capitalism.     

Degradation modeling based on gamma process models with random effects

The random effects in a gamma process are introduced in terms of its scale parameter. However, the scale parameter affects both its mean and variance. Hence, the variation of the degradation rates and the within degradation increments are expected to be large. For some products, the random effects affect just the rate or just the volatility of the process. Thus, two modifications of the parameters' structure of the gamma process are proposed. One implies that the random effects affect just the volatility and the second just the rate. A Bayesian estimation approach is provided and implemented in two case studies.