Project description:We discuss the results on improving the generalizability of individualized treatment rule following the work in Kallus [1] and Mo et al. [5]. We note that the advocated weights in Kallus [1] are connected to the efficient score of the contrast function. We further propose a likelihood-ratio-based method (LR-ITR) to accommodate covariate shifts, and compare it to the CTE-DR-ITR method proposed in Mo et al. [5]. We provide the upper-bound on the risk function of the target population when both the covariate shift and the contrast function shift are present. Numerical studies show that LR-ITR can outperform CTE-DR-ITR when there is only covariate shift.
Project description:This study highlights how the mortality plateau in Barbi and colleagues can be generated by low-frequency, randomly distributed age-misreporting errors. Furthermore, sensitivity of the late-life mortality plateau in Barbi and colleagues to the particular age range selected for regression is illustrated. Collectively, the simulation of age-misreporting errors in late-life human mortality data and a less-specific model choice than that of Barbi and colleagues highlight a clear alternative hypothesis to explanations based on evolution, the cessation of ageing, and population heterogeneity.
Project description:ObjectiveGrowing evidence suggests increasing frequencies of autoimmunity and autoimmune diseases, but findings are limited by the lack of systematic data and evolving approaches and definitions. This study was undertaken to investigate whether the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25-year span in the US.MethodsSerum ANA were measured by standard indirect immunofluorescence assays on HEp-2 cells in 13,519 participants age ≥12 years from the National Health and Nutrition Examination Survey, with approximately one-third from each of 3 time periods: 1988-1991, 1999-2004, and 2011-2012. We used logistic regression adjusted for sex, age, race/ethnicity, and survey design variables to estimate changes in ANA prevalence across the time periods.ResultsThe prevalence of ANA was 11.0% (95% confidence interval [95% CI] 9.7-12.6%) in 1988-1991, 11.4% (95% CI 10.2-12.8%) in 1999-2004, and 16.1% (95% CI 14.4-18.0%) in 2011-2012 (P for trend <0.0001), corresponding to ~22.3 million, ~26.6 million, and ~41.5 million affected individuals, respectively. Among adolescents age 12-19 years, ANA prevalence increased substantially, with odds ratios of 2.07 (95% CI 1.18-3.64) and 2.77 (95% CI 1.56-4.91) in the second and third time periods relative to the first (P for trend = 0.0004). ANA prevalence increased in both sexes (especially in men), older adults (age ≥50 years), and non-Hispanic white individuals. These increases in ANA prevalence were not explained by concurrent trends in weight (obesity/overweight), smoking exposure, or alcohol consumption.ConclusionThe prevalence of ANA in the US has increased considerably in recent years. Additional studies to determine factors underlying these increases in ANA prevalence could elucidate causes of autoimmunity and enable the development of preventative measures.
Project description:ObjectiveGrowing evidence suggests increasing frequencies of autoimmunity and certain autoimmune diseases, but findings are limited by the lack of systematic data and evolving approaches and definitions. This study was undertaken to investigate whether the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25-year span in the US.MethodsSerum ANA were measured by standard indirect immunofluorescence assays on HEp-2 cells in 14,211 participants age ≥12 years from the National Health and Nutrition Examination Survey, with approximately one-third from each of 3 time periods: 1988-1991, 1999-2004, and 2011-2012. We used logistic regression adjusted for sex, age, race/ethnicity, and survey design variables to estimate changes in ANA prevalence across the time periods.ResultsThe prevalence of ANA was 11.0% (95% confidence interval [95% CI] 9.7-12.6%) in 1988-1991, 11.5% (95% CI 10.3-12.8%) in 1999-2004, and 15.9% (95% CI 14.3-17.6%) in 2011-2012 (P for trend < 0.0001), which corresponds to ~22 million, ~27 million, and ~41 million affected individuals, respectively. Among adolescents age 12-19 years, ANA prevalence increased substantially, with odds ratios (ORs) of 2.02 (95% CI 1.16-3.53) and 2.88 (95% CI 1.64-5.04) in the second and third time periods relative to the first (P for trend < 0.0001). ANA prevalence increased in both sexes (especially in men), older adults (age ≥50 years), and non-Hispanic whites. These increases in ANA prevalence were not explained by concurrent trends in weight (obesity/overweight), smoking exposure, or alcohol consumption.ConclusionThe prevalence of ANA in the US has increased considerably in recent years. Additional studies to determine factors underlying these increases in ANA prevalence could elucidate causes of autoimmunity and enable the development of preventative measures.
Project description:Background and aimsThe National Health and Nutrition Examination Survey (NHANES) underestimates the true prevalence of HCV infection. By accounting for populations inadequately represented in NHANES, we created 2 models to estimate the national hepatitis C prevalence among US adults during 2017-2020.Approach and resultsThe first approach (NHANES+) replicated previous methodology by supplementing hepatitis C prevalence estimates among the US noninstitutionalized civilian population with a literature review and meta-analysis of hepatitis C prevalence among populations not included in the NHANES sampling frame. In the second approach (persons who injected drugs [PWID] adjustment), we developed a model to account for the underrepresentation of PWID in NHANES by incorporating the estimated number of adult PWID in the United States and applying PWID-specific hepatitis C prevalence estimates. Using the NHANES+ model, we estimated HCV RNA prevalence of 1.0% (95% CI: 0.5%-1.4%) among US adults in 2017-2020, corresponding to 2,463,700 (95% CI: 1,321,700-3,629,400) current HCV infections. Using the PWID adjustment model, we estimated HCV RNA prevalence of 1.6% (95% CI: 0.9%-2.2%), corresponding to 4,043,200 (95% CI: 2,401,800-5,607,100) current HCV infections.ConclusionsDespite years of an effective cure, the estimated prevalence of hepatitis C in 2017-2020 remains unchanged from 2013 to 2016 when using a comparable methodology. When accounting for increased injection drug use, the estimated prevalence of hepatitis C is substantially higher than previously reported. National action is urgently needed to expand testing, increase access to treatment, and improve surveillance, especially among medically underserved populations, to support hepatitis C elimination goals.
Project description:Root-secreted coumarins and the microbiota interact to improve iron nutrition in Arabidopsis. Harbort and Hashimoto et al. Cell Host & Microbe 2020
Project description:BackgroundAmong ESRD patients, obesity may improve dialysis-survival but decreases likelihood of transplantation, and as such, obesity prevalence may directly affect growth of the dialysis population.ObjectiveThe objective of this study was to assess BMI trends in the ESRD population as compared to the general population.Materials and methodsIncident adult ESRD patients were identified from the United States Renal Data System from 01/01/1995-12/31/2010 (n=1,458,350). Data from the Behavioral Risk Factor Surveillance System (n=4,303,471) represented the US population. Trends in BMI, obesity classes I (BMI of 30-34.9), II (BMI of 35-39.9), and III (BMI ≥ 40), were examined by year of dialysis initiation. Trends in BMI slope were compared between the ESRD and US populations using linear regression.ResultsMean BMI of ESRD patients in 1995 was 25.2 as compared to 29.4 in 2010, a 16.7% increase, while the US population's mean BMI increased from 25.3 to 27.2, a 7.5% increase. BMI increase among the ESRD population was significantly more rapid than among the US population (β: 0.16, 95% CI: 0.14-0.18, p<0.001).Conclusions and recommendationsMean BMI among the ESRD population is increasing more rapidly than the US population. Given decreased access to kidney transplantation among ESRD patients with obesity, future research should be directed at controlling healthcare expenditures by identifying strategies to address the obesity epidemic among the US ESRD population.