Applications of a simple regression model to acid rain data

This paper addresses two vital and seemingly simple questions concerning wet deposition of sulfates, a major contributor to acid rain. The first is to estimate the annual wet deposition of sulfate at a monitoring site under emissions that existed during the 1980s. This problem is complicated by missing data. The second is to estimate accurately the effect of a change in pollution emissions on concentrations of sulfate in precipitation. This problem is made difficult by the substantial natural variations in sulfate concentrations due to weather variations between years. As a tool for addressing both of these problems, we develop a regression model for the sulfate concentration of precipitation on a particular day as a function of amount of precipitation and time of the year. The model is used as a basis for imputing missing sulfate concentrations to handle the missing-data problem. It is also used to explain some of the variability in annual sulfate concentrations due to meteorology and hence provide more accurate estimates of the effect of changes in emissions.     

Research Review: Young people leaving care

This paper reviews the international research on young people leaving care. Set in the context of a social exclusion framework, it explores young people’s accelerated and compressed transitions to adulthood, and discusses the development and classification of leaving care services in responding to their needs. It then considers the evidence from outcome studies and argues that adopting a resilience framework suggests that young people leaving care may fall into three groups: young people ‘moving on’, ‘survivors’ and ‘victims’. In concluding, it argues that these three pathways are associated with the quality of care young people receive, their transitions from care and the support they receive after care.     

Rosalie Wolf Memorial Lecture: A logic model to measure the impacts of World Elder Abuse Awareness Day

ABSTRACT

This commentary discusses the need to evaluate the impact of World Elder Abuse Awareness Day activities, the elder abuse field’s most sustained public awareness initiative. A logic model is proposed with measures for short-term, medium-term, and long-term outcomes for community-based programs.     

The influence of ethnicity, socioeconomic status, and psychological barriers on use of mammography

This study assessed the relative influence of psychological barriers, SES, and ethnic differences in mammography use for a community sample of 586 White, 227 Black, and 150 Hispanic women. Confirmatory factor analyses with latent variables indicated plausible factor structures for all groups on items related to barriers to mammography. Summed indicators of SES, fear of radiation, embarrassment, pain, anxiety, and cost concerns were correlated significantly with mammography use for the pooled group. Separate analyses by ethnicity indicated a substantial relationship between mammography use and cost concerns by White and Black women, and fear of pain by Black and Hispanic women. Use of mammography was associated more highly with SES among Hispanic women. Pooled logistic regression analyses controlling for SES and ethnicity showed that the psychological barriers, especially concern about cost, remained important independent predictors of mammography use. We explore sociocultural explanations for less mammography use by Hispanic women, especially those less acculturated.     

Association between physical partner violence, posttraumatic stress, childhood trauma, and suicide attempts in a community sample of women

Our objective was to estimate the prevalence of intimate partner violence (IPV) and to explore its association with childhood maltreatment, substance misuse, posttraumatic stress, and suicidal behavior in a representative community sample of women. IPV was operationalized as a "physical attack or beating by a spouse, boyfriend, or live-in partner." We surveyed 637 women in Memphis, Tennessee, by telephone survey. Sixteen percent reported ever experiencing IPV by a male partner, and 75% endorsed multiple assaultive acts. Of abused women, 5.9% met current PTSD diagnostic criteria, and an additional 11.8% were assessed with subthreshold symptoms. Abused women were more likely than other women to be divorced, to have less than 13 years education, to endorse high levels of childhood victimization, to have abused drugs and alcohol, and to have attempted suicide. Twenty-three percent of IPV+ (abused) women reported a suicide attempt at some time in their lives compared with 3% of IPV- (nonabused) women (p < .0001). Further, multiple logistic regression analysis showed that childhood sexual and emotional abuse and low educational attainment were the only significant predictors of IPV. These results suggest that in women who endorse IPV, careful inquiry of past abuse, trauma-related symptoms, suicidal behavior, and drug use may be important, so that interventions can be both timely and appropriate.     

SYNSEG – Eine Methode zur <Emphasis Type="Italic">syn</Emphasis>taxgeleiteten <Emphasis Type="Italic">Seg</Emphasis>mentierung von Kodiereinheiten für die Analyse von Gruppenprozessen

Observing group processes allows for obtaining insights into what successful groups do differently than less successful groups. In doing so, observational data is typically transcribed or integrated into coding software, coding units are identified, and coding systems are applied to code these units with regard to the respective content. While there are systems available for transcribing and coding observational group data, the segmentation of coding units is mostly left to the coders’ intuition. Standardized and tested procedures for identifying coding units are not available for group research, limiting the reliability of coding group data. We introduce a method which aims at systematically identifying and segmenting coding units to enhance coding reliability. SYNSEG – syntax-based segmentation of coding units – suggests ten rules to segment coding units based on German grammar. To test for reliability, two coders applied SYNSEG for segmenting a 60-minute group discussion. A normalised Levensthein Distance of nD = 0,19 indicated satisfying coder agreement. We discuss the relevance and applicability of SYNSEG in applied group research.     

World Elder Abuse Awareness Day: The Concept,the Reality,and the Promise

This commentary traces the origins and evolution of the World Elder Abuse Awareness Day (WEAAD) initiative and provides recommendations for increasing WEAAD’s impact as a catalyst for a coordinated movement within the United States.     

Subgroup analyses in cost‐effectiveness analyses to support health technology assessments

‘Success’ in drug development is bringing to patients a new medicine that has an acceptable benefit–risk profile and that is also cost‐effective. Cost‐effectiveness means that the incremental clinical benefit is deemed worth paying for by a healthcare system, and it has an important role in enabling manufacturers to obtain new medicines to patients as soon as possible following regulatory approval. Subgroup analyses are increasingly being utilised by decision‐makers in the determination of the cost‐effectiveness of new medicines when making recommendations. This paper highlights the statistical considerations when using subgroup analyses to support cost‐effectiveness for a health technology assessment. The key principles recommended for subgroup analyses supporting clinical effectiveness published by Paget et al. are evaluated with respect to subgroup analyses supporting cost‐effectiveness. A health technology assessment case study is included to highlight the importance of subgroup analyses when incorporated into cost‐effectiveness analyses. In summary, we recommend planning subgroup analyses for cost‐effectiveness analyses early in the drug development process and adhering to good statistical principles when using subgroup analyses in this context. In particular, we consider it important to provide transparency in how subgroups are defined, be able to demonstrate the robustness of the subgroup results and be able to quantify the uncertainty in the subgroup analyses of cost‐effectiveness. Copyright © 2014 John Wiley & Sons, Ltd.