Scale development and validation are critical to much of the work in the health, social, and behavioral sciences. However, the constellation of techniques required for scale development and evaluation can be onerous, jargon-filled, unfamiliar, and resource-intensive. Further, it is often not a part of graduate training. Therefore, our goal was to concisely review the process of scale development in as straightforward a manner as possible, both to facilitate the development of new, valid, and reliable scales, and to help improve existing ones. To do this, we have created a primer for best practices for scale development in measuring complex phenomena. This is not a systematic review, but rather the amalgamation of technical literature and lessons learned from our experiences spent creating or adapting a number of scales over the past several decades. We identified three phases that span nine steps. In the first phase, items are generated and the validity of their content is assessed. In the second phase, the scale is constructed. Steps in scale construction include pre-testing the questions, administering the survey, reducing the number of items, and understanding how many factors the scale captures. In the third phase, scale evaluation, the number of dimensions is tested, reliability is tested, and validity is assessed. We have also added examples of best practices to each step. In sum, this primer will equip both scientists and practitioners to understand the ontology and methodology of scale development and validation, thereby facilitating the advancement of our understanding of a range of health, social, and behavioral outcomes.

Food insecurity has been associated with diverse developmental consequences for U.S. children primarily from cross-sectional studies. We used longitudinal data to investigate how food insecurity over time related to changes in reading and mathematics test performance, weight and BMI, and social skills in children. Data were from the Early Childhood Longitudinal Study-Kindergarten Cohort, a prospective sample of approximately 21,000 nationally representative children entering kindergarten in 1998 and followed through 3rd grade. Food insecurity was measured by parent interview using a modification of the USDA module in which households were classified as food insecure if they reported > or =1 affirmative response in the past year. Households were grouped into 4 categories based on the temporal occurrence of food insecurity in kindergarten and 3rd grade. Children's academic performance, height, and weight were assessed directly. Children's social skills were reported by teachers. Analyses examined the effects of modified food insecurity on changes in child outcomes using lagged, dynamic, and difference (i.e., fixed-effects) models and controlling for child and household contextual variables. In lagged models, food insecurity was predictive of poor developmental trajectories in children before controlling for other variables. Food insecurity thus serves as an important marker for identifying children who fare worse in terms of subsequent development. In all models with controls, food insecurity was associated with outcomes, and associations differed by gender. This study provides the strongest empirical evidence to date that food insecurity is linked to specific developmental consequences for children, and that these consequences may be both nutritional and nonnutritional.

Food insecurity, which affects >1 billion people worldwide, is inextricably linked to the HIV epidemic. We present a conceptual framework of the multiple pathways through which food insecurity and HIV/AIDS may be linked at the community, household, and individual levels. Whereas the mechanisms through which HIV/AIDS can cause food insecurity have been fairly well elucidated, the ways in which food insecurity can lead to HIV are less well understood. We argue that there are nutritional, mental health, and behavioral pathways through which food insecurity leads to HIV acquisition and disease progression. Specifically, food insecurity can lead to macronutrient and micronutrient deficiencies, which can affect both vertical and horizontal transmission of HIV, and can also contribute to immunologic decline and increased morbidity and mortality among those already infected. Food insecurity can have mental health consequences, such as depression and increased drug abuse, which, in turn, contribute to HIV transmission risk and incomplete HIV viral load suppression, increased probability of AIDS-defining illness, and AIDS-related mortality among HIV-infected individuals. As a result of the inability to procure food in socially or personally acceptable ways, food insecurity also contributes to risky sexual practices and enhanced HIV transmission, as well as to antiretroviral therapy nonadherence, treatment interruptions, and missed clinic visits, which are strong determinants of worse HIV health outcomes. More research on the relative importance of each of these pathways is warranted because effective interventions to reduce food insecurity and HIV depend on a rigorous understanding of these multifaceted relationships.

This study provides evidence that low intakes of energy and selected nutrients are independently associated with frailty.

Food insecurity is a daily reality for hundreds of millions of people around the world. Although its most extreme manifestations are often obvious, many other households facing constraints in their access to food are less identifiable. Operational agencies lack a method for differentiating households at varying degrees of food insecurity in order to target and evaluate their interventions. This chapter provides an overview of a set of papers associated with a research initiative that seeks to identify more precise, yet simple, measures of household food insecurity. The overview highlights three main conceptual developments associated with practical approaches to measuring constraints in access to food: 1) a shift from using measures of food availability and utilization to measuring "inadequate access"; 2) a shift from a focus on objective to subjective measures; and 3) a growing emphasis on fundamental measurement as opposed to reliance on distal, proxy measures. Further research is needed regarding 1) how well measures of household food insecurity designed for chronically food-insecure contexts capture the processes leading to, and experience of, acute food insecurity, 2) the impact of short-term shocks, such as major floods or earthquake, on household behaviors that determine responses to food security questions, 3) better measurement of the interaction between severity and frequency of household food insecurity behaviors, and 4) the determination of whether an individual's response to survey questions can be representative of the food insecurity experiences of all members of the household.

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Mating stimulates the rate of egg-laying by female insects. In Drosophila melanogaster this stimulation is initially caused by seminal fluid molecules transferred from the male (Acps or accessory gland proteins; reviewed in [1] [2] [3]). Egg-laying is a multi-step process. It begins with oocyte release by the ovaries, followed by egg movement down the oviducts and the deposition of eggs onto the substratum. Although two Acps are known to stimulate egg-laying [4] [5], they were detected by assays that do not discriminate between the steps of this process or allow examination of its earliest changes [4] [5] [6] [7]. To determine how egg-laying is regulated, we developed a generally applicable assay to separate the process into quantifiable steps, allowing us to assess the ovulation pattern and rate of egg movement. As the steps are interdependent yet potentially subject to independent controls, we determined the contribution of each step and effector independent of the others. We used a statistical method [8] [9] that separately considers and quantifies each 'path' to a common end. We found that the prohormone-like molecule Acp26Aa [5] [10] stimulates the first step in egg-laying - release of oocytes by the ovary. During mating, Acp26Aa begins to accumulate at the base of the ovaries, a position consistent with action on the ovarian musculature to mediate oocyte release. Understanding how individual Acps regulate egg-laying in fruitflies will help provide a full molecular picture of insects' prodigious fertility, of reproductive hormones, and of the roles of these rapidly evolving proteins [11] [12].