Subjective health in adolescence: Comparing the reliability of contemporaneous, retrospective, and proxy reports of overall health.

Self-rated health (SRH) is one of the most important social science measures of health. Yet its measurement properties remain poorly understood. Most studies ignore the measurement error in SRH despite the bias resulting from even random measurement error. Our goal is to estimate the measurement reliability of SRH in contemporaneous, retrospective, and proxy indicators. We use the National Longitudinal Study of Adolescent to Adult Health to estimate the reliability of SRH relative to proxy assessments and respondents' recollections of past health. Even the best indicators - contemporaneous self-reports - have a modest reliability of ~0.6; retrospective and proxy assessments fare much worse, with reliability less than 0.2. Moreover, not correcting for measurement error in SRH leads to a ~20-40% reduction in its correlation with other measures of health. Researchers should be skeptical of analyses that treat these subjective reports as explanatory variables and fail to take account of their substantial measurement error.

Evidence for Association between SH2B1 Gene Variants and Glycated Hemoglobin in Nondiabetic European American Young Adults: The Add Health Study.

Glycated hemoglobin (HbA1c) is used to classify glycaemia and type 2 diabetes (T2D). Body mass index (BMI) is a predictor of HbA1c levels and T2D. We tested 43 established BMI and obesity loci for association with HbA1c in a nationally representative multiethnic sample of young adults from the National Longitudinal Study of Adolescent to Adult Health [Add Health: age 24-34 years; n = 5641 European Americans (EA); 1740 African Americans (AA); 1444 Hispanic Americans (HA)] without T2D, using two levels of covariate adjustment (Model 1: age, sex, smoking, and geographic region; Model 2: Model 1 covariates plus BMI). Bonferroni adjustment was made for 43 SNPs and we considered P < 0.0011 statistically significant. Means (SD) for HbA1c were 5.4% (0.3) in EA, 5.7% (0.4) in AA, and 5.5% (0.3) in HA. We observed significant evidence for association with HbA1c for two variants near SH2B1 in EA (rs4788102, P = 2.2 × 10(-4) ; rs7359397, P = 9.8 × 10(-4) ) for Model 1. Both results were attenuated after adjustment for BMI (rs4788102, P = 1.7 × 10(-3) ; rs7359397, P = 4.6 × 10(-3) ). No variant reached Bonferroni-corrected significance in AA or HA. These results suggest that SH2B1 polymorphisms are associated with HbA1c, largely independent of BMI, in EA young adults.

Interaction of smoking and obesity susceptibility loci on adolescent BMI: The National Longitudinal Study of Adolescent to Adult Health.

BACKGROUND: Adolescence is a sensitive period for weight gain and risky health behaviors, such as smoking. Genome-wide association studies (GWAS) have identified loci contributing to adult body mass index (BMI). Evidence suggests that many of these loci have a larger influence on adolescent BMI. However, few studies have examined interactions between smoking and obesity susceptibility loci on BMI. This study investigates the interaction of current smoking and established BMI SNPs on adolescent BMI. Using data from the National Longitudinal Study of Adolescent to Adult Health, a nationally-representative, prospective cohort of the US school-based population in grades 7 to 12 (12-20 years of age) in 1994-95 who have been followed into adulthood (Wave II 1996; ages 12-21, Wave III; ages 18-27), we assessed (in 2014) interactions of 40 BMI-related SNPs and smoking status with percent of the CDC/NCHS 2000 median BMI (%MBMI) in European Americans (n = 5075), African Americans (n = 1744) and Hispanic Americans (n = 1294). RESULTS: Two SNPs showed nominal significance for interaction (p < 0.05) between smoking and genotype with %MBMI in European Americans (EA) (rs2112347 (POC5): ß = 1.98 (0.06, 3.90), p = 0.04 and near rs571312 (MC4R): ß 2.15 (-0.03, 4.33) p = 0.05); and one SNP showed a significant interaction effect after stringent correction for multiple testing in Hispanic Americans (HA) (rs1514175 (TNNI3K): ß 8.46 (4.32, 12.60), p = 5.9E-05). Stratifying by sex, these interactions suggest a stronger effect in female smokers. CONCLUSIONS: Our study highlights potentially important sex differences in obesity risk by smoking status in adolescents, with those who may be most likely to initiate smoking (i.e., adolescent females), being at greatest risk for exacerbating genetic obesity susceptibility.

Gene-environment interactions related to body mass: School policies and social context as environmental moderators.

This paper highlights the role of institutional resources and policies, whose origins lie in political processes, in shaping the genetic etiology of body mass among a national sample of adolescents. Using data from Waves I and II of the National Longitudinal Study of Adolescent Health, we decompose the variance of body mass into environmental and genetic components. We then examine the extent to which the genetic influences on body mass are different across the 134 schools in the study. Taking advantage of school differences in both health-related policies and social norms regarding body size, we examine how institutional resources and policies alter the relative impact of genetic influences on body mass. For the entire sample, we estimate a heritability of .82, with the remaining .18 due to unique environmental factors. However, we also show variation about this estimate and provide evidence suggesting that social norms and institutional policies often mask genetic vulnerabilities to increased weight. Empirically, we demonstrate that more-restrictive school policies and policies designed to curb weight gain are also associated with decreases the proportion of variance in body mass that is due to additive genetic influences.

A Bayesian approach to comparing common models of life-course epidemiology.

BACKGROUND: Life-course epidemiology studies people's health over long periods, treating repeated measures of their experiences (usually risk factors) as predictors or causes of subsequent morbidity and mortality. Three hypotheses or models often guide the analyst in assessing these sequential risks: the accumulation model (all measurement occasions are equally important for predicting the outcome), the critical period model (only one occasion is important) and the sensitive periods model (a catch-all model for any other pattern of temporal dependence). METHODS: We propose a Bayesian omnibus test of these three composite models, as well as post hoc decompositions that identify their best respective sub-models. We test the approach via simulations, before presenting an empirical example that relates five sequential measurements of body weight to an RNAseq measure of colorectal-cancer disposition. RESULTS: The approach correctly identifies the life-course model under which the data were simulated. Our empirical cohort study indicated with >90% probability that colorectal-cancer disposition reflected a sensitive process, with current weight being most important but prior body weight also playing a role. CONCLUSIONS: The Bayesian methods we present allow precise inferences about the probability of life-course models given the data and are applicable in realistic scenarios involving causal analysis and missing data.

Household Financial Assets Inequity and Health Disparities Among Young Adults: Evidence from the National Longitudinal Study of Adolescent to Adult Health.

INTRODUCTION: Research has established a strong relationship between financial resources and health outcomes. Yet, little is known about the effects of assets disparities on health outcomes, especially during the critical period when adolescents transition to adults. Methods: Using data from the National Longitudinal Study of Adolescent to Adult Health (n = 10,861), this study investigated the relationships between three household total assets value groups (low, moderate, and high assets) and three net worth groups (negative, neutral, and positive) on young adults' general health, obese, and depression. RESULTS: Both assets and debts were related to young adults' health status, young adults with more assets and positive net worth have higher probability to report a better level of both general health and depression. Young adult's obesity was found to be associated with net worth but not with assets. CONCLUSIONS AND IMPLICATIONS: Our work connects health promotion with poverty alleviation to address the challenge of health disparity. A better understanding of different forms of financial resources (e.g., income, assets, and debt) and their dynamic relationships with health outcomes will contribute to developing effective asset-based interventions for promoting health status. Particularly, current policy and practice should consider the importance of resolving and clearing debt.

Beyond Race/Ethnicity: Skin Color and Cardiometabolic Health Among Blacks and Hispanics in the United States.

We investigated whether darker interviewer-ascribed skin color is associated with worse cardiometabolic health among young adult Blacks and Hispanics in the United States. Our sample was comprised of 2,128 non-Hispanic Blacks and 1603 Hispanics aged 24-32, who were in high school in the United States in 1994. We used logistic and OLS regression to predict obesity, hypertension, diabetes, and cardiometabolic risk. We tested the interaction between Hispanic immigrant generation and ascribed skin color. Darker ascribed skin color predicted worse cardiometabolic health among both young adult Blacks and Hispanics. Among Hispanics, the associations were strongest among third and higher generation respondents. Our findings suggest that among US Blacks and Hispanics how individuals are perceived by others via their skin color is significantly associated with their health and well-being. Gradients in cardiometabolic health in young adulthood will likely contribute to gradients in cardiovascular disease and all-cause mortality later in life.

Analysis of False-Negative Cancer Cases Identified with a Mammography Audit.

The purpose of this study was to analyze the causes of false-negative breast imaging in symptomatic and asymptomatic patients, as defined by cancer diagnosed within 1 year of a nonsuspicious mammogram. A computerized audit of 27,305 mammograms performed between November 1992 and December 1993 identified 50 patients who developed malignancy within 1 year of a mammographic report indicating negative, benign, or probably benign results. The audit revealed 26,661 mammograms interpreted as negative, benign, or probably benign. Of these, 50 patients were diagnosed with carcinoma within 1 year. Thirteen of the cancers were not visible retrospectively. Five were seen only in retrospect. Thirty-two were seen prospectively, of which 5 were interpreted as benign and 27 were interpreted as probably benign. Seventeen of the 27 probably benign were recommended for 6-month follow-up. Ten of the 27 probably benign had immediate ultrasound-guided fine needle aspiration cytology yielding unsuspected malignancy. In most (32/50) false-negative cases the lesions were seen prospectively but were interpreted as benign or probably benign. Ultrasound-guided aspiration averted a delayed diagnosis of malignancy in 20% (10/50) of the false-negative imaging interpretations. Six-month follow-up studies were helpful for 12 of 17 cases, where the lesions progressed within 1 year.

Multiple levels of social disadvantage and links to obesity in adolescence and young adulthood.

BACKGROUND: The rise in adolescent obesity has become a public health concern, especially because of its impact on disadvantaged youth. This article examines the role of disadvantage at the family-, peer-, school-, and neighborhood-level, to determine which contexts are related to obesity in adolescence and young adulthood. METHODS: We analyzed longitudinal data from Waves I (1994-1995), II (1996), and III (2001-2002) of the National Longitudinal Study of Adolescent Health, a nationally representative population-based sample of adolescents in grades 7-12 in 1995 who were followed into young adulthood. We assessed the relationship between obesity in adolescence and young adulthood, and disadvantage (measured by low parent education in adolescence) at the family-, peer-, school-, and neighborhood-level using multilevel logistic regression. RESULTS: When all levels of disadvantage were modeled simultaneously, school-level disadvantage was significantly associated with obesity in adolescence for males and females and family-level disadvantage was significantly associated with obesity in young adulthood for females. CONCLUSIONS: Schools may serve as a primary setting for obesity prevention efforts. Because obesity in adolescence tracks into adulthood, it is important to consider prevention efforts at this stage in the life course, in addition to early childhood, particularly among disadvantaged populations.

Prevalence of HIV infection among young adults in the United States: results from the Add Health study.

OBJECTIVES: We estimated HIV prevalence rates among young adults in the United States. METHODS: We used survey data from the third wave of the National Longitudinal Study of Adolescent Health, a random sample of nearly 19000 young adults initiated in 1994-1995. Consenting respondents were screened for the presence of antibodies to HIV-1 in oral mucosal transudate specimens. We calculated prevalence rates, accounting for survey design, response rates, and test performance. RESULTS: Among the 13184 participants, the HIV prevalence rate was 1.0 per 1000 (95% confidence interval [CI] = 0.4, 1.7). Gender-specific prevalence rates were similar, but rates differed markedly between non-Hispanic Blacks (4.9 per 1000; 95% CI=1.8, 8.7) and members of other racial/ethnic groups (0.22 per 1000; 95% CI=0.00, 0.64). CONCLUSIONS: Racial disparities in HIV in the United States are established early in the life span, and our data suggest that 15% to 30% of all cases of HIV occur among individuals younger than 25 years.

Recall and detection rates in screening mammography.

BACKGROUND: The authors investigated the correlation between recall and detection rates in a group of 10 radiologists who had read a high volume of screening mammograms in an academic institution. METHODS: Practice-related and outcome-related databases of verified cases were used to compute recall rates and tumor detection rates for a group of 10 Mammography Quality Standard Act (MQSA)-certified radiologists who interpreted a total of 98,668 screening mammograms during the years 2000, 2001, and 2002. The relation between recall and detection rates for these individuals was investigated using parametric Pearson (r) and nonparametric Spearman (rho) correlation coefficients. The effect of the volume of mammograms interpreted by individual radiologists was assessed using partial correlations controlling for total reading volumes. RESULTS: A wide variability of recall rates (range, 7.7-17.2%) and detection rates (range, 2.6-5.4 per 1000 mammograms) was observed in the current study. A statistically significant correlation (P < 0.05) between recall and detection rates was observed in this group of 10 experienced radiologists. The results remained significant (P < 0.05) after accounting for the volume of mammograms interpreted by each radiologist. CONCLUSIONS: Optimal performance in screening mammography should be evaluated quantitatively. The general pressure to reduce recall rates through "practice guidelines" to below a fixed level for all radiologists should be assessed carefully.