566 research outputs found

    Why Welfare Caseloads Fluctuate: A Review of Research on AFDC, SSI, and the Food Stamps Program

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    This report reviews research on trends in the caseloads of three means-tested transfer programs in the United States: Aid to Families with Dependent Children (AFDC), Supplemental Security Income (SSI), and the Food Stamp Program (FSP). Trends in caseloads are the result of 1) program parameters and interactions between programs, 2) economic conditions, 3) norms and values, and 4) demographic characteristics. Most research tries to estimate the relative importance of the first two. The research suggests that all else equal, as welfare programs become more generous and easier to get caseloads increase. Caseload changes are also greatest when two or more of these four factors provide similar incentives for people to alter their behavior. For example, recent declines in AFDC and the FSP caseloads appear to be the result of the combined effect of the strong U.S. economy and policy changes that made work more available and more attractive compared to welfare. Similarly, program interactions are important. When programs provide opposing incentives, they reduce the behavioral response to either incentive, and when programs provide similar incentives, the behavioral response is greater than if only one program provided the incentive. Finally, incentives do not affect everyone in the same way. Program changes that benefit some recipients may hurt others. The research on caseloads has many limitations that reduce confidence in these estimated effects. The research is almost all based on reduced-form models, which tell us little about the causal mechanisms through which exogenous factors affect caseloads. The theory about these causal mechanisms is weak resulting in the possibility of mis-specification and many key variables are poorly measured or omitted.

    Undergraduate public health education: a workforce perspective

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    Objective: To describe the career paths of students who majored in public health at the undergraduate level and to assess the skills and knowledge these g raduates believed were most useful to them in the public health workforce. Method: A telephone survey was conducted of all graduates from Adelaide University\u27s Bachelor of Health Sciences degree from 1992-99 who had majored in public health (124 graduates). Results: The response rate to the graduate survey was 71 %. Using the definition of public health functions from the National Delphi Study on Public Health Functions to delineate the public health workforce, 59% of respondents were employed in public health. Graduates working in public health valued generic skills such as communication and collaboration more highly than more specific public health skills and knowledge areas. However, they also believed their undergraduate course would have been improved by a more practical orientation. Conclusions: A high proportion of graduates from this generalist degree who major in public health find employment in the public health workforce. They greatly value the generic skills associated with their undergraduate public health education and believe their entry into the workforce would have been further facilitated by stronger links between their academic program and the working environment of public health professionals. Implications: Studies of workforce training programs in public health must differentiate between the educational needs of undergraduate and postgraduate students. In particular, strategies need to be developed to provide stronger links between undergraduate students and the public health workforce

    Identification of a Spike-Specific CD8<sup>+</sup> T-Cell Epitope Following Vaccination Against the Middle East Respiratory Syndrome Coronavirus in Humans

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    Licensed vaccines against the Middle East respiratory syndrome coronavirus (MERS-CoV), an emerging pathogen of concern, are lacking. The modified vaccinia virus Ankara vector-based vaccine MVA-MERS-S, expressing the MERS-CoV-spike glycoprotein (MERS-S), is one of 3 candidate vaccines in clinical development and elicits robust humoral and cellular immunity. Here, we identified for the first time a MERS-S-specific CD8+ T-cell epitope in an HLA-A∗03:01/HLA-B∗35:01-positive vaccinee using a screening assay, intracellular cytokine staining, and in silico epitope prediction. As evidence from MERS-CoV infection suggests a protective role of long-lasting CD8+ T-cell responses, the identification of epitopes will facilitate longitudinal analyses of vaccine-induced T-cell immunity.</p

    Performance of a Limiting-Antigen Avidity Enzyme Immunoassay for Cross-Sectional Estimation of HIV Incidence in the United States

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    Background: A limiting antigen avidity enzyme immunoassay (HIV-1 LAg-Avidity assay) was recently developed for cross-sectional HIV incidence estimation. We evaluated the performance of the LAg-Avidity assay alone and in multi-assay algorithms (MAAs) that included other biomarkers. Methods and Findings: Performance of testing algorithms was evaluated using 2,282 samples from individuals in the United States collected 1 month to >8 years after HIV seroconversion. The capacity of selected testing algorithms to accurately estimate incidence was evaluated in three longitudinal cohorts. When used in a single-assay format, the LAg-Avidity assay classified some individuals infected >5 years as assay positive and failed to provide reliable incidence estimates in cohorts that included individuals with long-term infections. We evaluated >500,000 testing algorithms, that included the LAg-Avidity assay alone and MAAs with other biomarkers (BED capture immunoassay [BED-CEIA], BioRad-Avidity assay, HIV viral load, CD4 cell count), varying the assays and assay cutoffs. We identified an optimized 2-assay MAA that included the LAg-Avidity and BioRad-Avidity assays, and an optimized 4-assay MAA that included those assays, as well as HIV viral load and CD4 cell count. The two optimized MAAs classified all 845 samples from individuals infected >5 years as MAA negative and estimated incidence within a year of sample collection. These two MAAs produced incidence estimates that were consistent with those from longitudinal follow-up of cohorts. A comparison of the laboratory assay costs of the MAAs was also performed, and we found that the costs associated with the optimal two assay MAA were substantially less than with the four assay MAA. Conclusions: The LAg-Avidity assay did not perform well in a single-assay format, regardless of the assay cutoff. MAAs that include the LAg-Avidity and BioRad-Avidity assays, with or without viral load and CD4 cell count, provide accurate incidence estimates

    a global network of chronic kidney disease cohorts

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    Background Chronic kidney disease (CKD) is a global health burden, yet it is still underrepresented within public health agendas in many countries. Studies focusing on the natural history of CKD are challenging to design and conduct, because of the long time-course of disease progression, a wide variation in etiologies, and a large amount of clinical variability among individuals with CKD. With the difference in health-related behaviors, healthcare delivery, genetics, and environmental exposures, this variability is greater across countries than within one locale and may not be captured effectively in a single study. Methods Studies were invited to join the network. Prerequisites for membership included: 1) observational designs with a priori hypotheses and defined study objectives, patient-level information, prospective data acquisition and collection of bio-samples, all focused on predialysis CKD patients; 2) target sample sizes of 1,000 patients for adult cohorts and 300 for pediatric cohorts; and 3) minimum follow-up of three years. Participating studies were surveyed regarding design, data, and biosample resources. Results Twelve prospective cohort studies and two registries covering 21 countries were included. Participants age ranges from >2 to >70 years at inclusion, CKD severity ranges from stage 2 to stage 5. Patient data and biosamples (not available in the registry studies) are measured yearly or biennially. Many studies included multiple ethnicities; cohort size ranges from 400 to more than 13,000 participants. Studies’ areas of emphasis all include but are not limited to renal outcomes, such as progression to ESRD and death. Conclusions iNET-CKD (International Network of CKD cohort studies) was established, to promote collaborative research, foster exchange of expertise, and create opportunities for research training. Participating studies have many commonalities that will facilitate comparative research; however, we also observed substantial differences. The diversity we observed across studies within this network will be able to be leveraged to identify genetic, behavioral, and health services factors associated with the course of CKD. With an emerging infrastructure to facilitate interactions among the investigators of iNET-CKD and a broadly defined research agenda, we are confident that there will be great opportunity for productive collaborative investigations involving cohorts of individuals with CKD

    A Comparison of Two Measures of HIV Diversity in Multi-Assay Algorithms for HIV Incidence Estimation

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    Background: Multi-assay algorithms (MAAs) can be used to estimate HIV incidence in cross-sectional surveys. We compared the performance of two MAAs that use HIV diversity as one of four biomarkers for analysis of HIV incidence. Methods: Both MAAs included two serologic assays (LAg-Avidity assay and BioRad-Avidity assay), HIV viral load, and an HIV diversity assay. HIV diversity was quantified using either a high resolution melting (HRM) diversity assay that does not require HIV sequencing (HRM score for a 239 base pair env region) or sequence ambiguity (the percentage of ambiguous bases in a 1,302 base pair pol region). Samples were classified as MAA positive (likely from individuals with recent HIV infection) if they met the criteria for all of the assays in the MAA. The following performance characteristics were assessed: (1) the proportion of samples classified as MAA positive as a function of duration of infection, (2) the mean window period, (3) the shadow (the time period before sample collection that is being assessed by the MAA), and (4) the accuracy of cross-sectional incidence estimates for three cohort studies. Results: The proportion of samples classified as MAA positive as a function of duration of infection was nearly identical for the two MAAs. The mean window period was 141 days for the HRM-based MAA and 131 days for the sequence ambiguity-based MAA. The shadows for both MAAs were <1 year. Both MAAs provided cross-sectional HIV incidence estimates that were very similar to longitudinal incidence estimates based on HIV seroconversion. Conclusions: MAAs that include the LAg-Avidity assay, the BioRad-Avidity assay, HIV viral load, and HIV diversity can provide accurate HIV incidence estimates. Sequence ambiguity measures obtained using a commercially-available HIV genotyping system can be used as an alternative to HRM scores in MAAs for cross-sectional HIV incidence estimation
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