Adaptive Time-Location Sampling for COMPASS: A SARS-CoV-2 Prevalence Study in Fifteen Diverse Communities in the United States

BACKGROUND

COVID-19 has placed a disproportionate burden on underserved racial and ethnic groups, community members working in essential industries, those living in areas of high population density, and those reliant on in-person services such as transportation. The goal of this study was to estimate the cross-sectional prevalence of SARS-CoV-2 (active SARS-CoV-2 or prior SARS-CoV-2 infection) in children and adults attending public venues in 15 sociodemographically diverse communities in the United States and to develop a statistical design that could be rigorously implemented amidst unpredictable stay-at-home COVID-19 guidelines.

METHODS

We used time-location sampling with complex sampling involving stratification, clustering of units, and unequal probabilities of selection to recruit individuals from selected communities. We safely conducted informed consent, specimen collection, and face-to-face interviews outside of public venues immediately following recruitment.

RESULTS

We developed an innovative sampling design that adapted to constraints such as closure of venues, changing infection hotspots, and uncertain policies. We updated both the sampling frame and the selection probabilities over time using information acquired from prior weeks. We created site-specific survey weights that adjusted sampling probabilities for nonresponse and calibrated to county-level margins on age and sex at birth.

CONCLUSIONS

Although the study itself was specific to COVID-19, the strategies presented in this article could serve as a case study that can be adapted for performing population-level inferences in similar settings and could help inform rapid and effective responses to future global public health challenges.

Prevalence of SARS-CoV-2 Infection among Children and Adults in 15 US Communities, 2021

During January-August 2021, the Community Prevalence of SARS-CoV-2 Study used time/location sampling to recruit a cross-sectional, population-based cohort to estimate SARS-CoV-2 seroprevalence and nasal swab sample PCR positivity across 15 US communities. Survey-weighted estimates of SARS-CoV-2 infection and vaccine willingness among participants at each site were compared within demographic groups by using linear regression models with inverse variance weighting. Among 22,284 persons >2 months of age and older, median prevalence of infection (prior, active, or both) was 12.9% across sites and similar across age groups. Within each site, average prevalence of infection was 3 percentage points higher for Black than White persons and average vaccine willingness was 10 percentage points lower for Black than White persons and 7 percentage points lower for Black persons than for persons in other racial groups. The higher prevalence of SARS-CoV-2 infection among groups with lower vaccine willingness highlights the disparate effect of COVID-19 and its complications.

ADAPTIVE TIME LOCATION SAMPLING FOR COMPASS, A SARS-COV-2 PREVALENCE STUDY IN FIFTEEN DIVERSE COMMUNITIES IN THE UNITED STATES

The COVPN 5002 (COMPASS) study aimed to estimate the prevalence of SARS-CoV-2 (active SARS-CoV-2 or prior SARS-CoV-2 infection) in children and adults attending public venues in 15 socio-demographically diverse communities in the United States. To protect against potential challenges in implementing traditional sampling strategies, time-location sampling (TLS) using complex sampling involving stratification, clustering of units, and unequal probabilities of selection was used to recruit individuals from neighborhoods in selected communities. The innovative design adapted to constraints such as closure of venues; changing infection hotspots; and uncertain policies. Recruitment of children and the elderly raised additional challenges in sample selection and implementation. To address these challenges, the TLS design adaptively updated both the sampling frame and the selection probabilities over time using information acquired from prior weeks. Although the study itself was specific to COVID-19, the strategies presented in this paper could serve as a case study that can be adapted for performing rigorous population-level inferences in similar settings and could help inform rapid and effective responses to future global public health challenges.

Telomere Length and Lung Cancer Mortality among Heavy Smokers

Background: Accumulating evidence suggests that short telomere length is associated with increased overall mortality, but the relationship with cancer mortality is less clear. We examined whether telomere length (global, and chromosome arm 5p- and 13q-specific) is associated with lung cancer mortality among cases from the β-Carotene and Retinol Efficacy Trial of heavy smokers.Methods: Telomere length was measured on average 6 years before diagnosis for 788 lung cancer cases. Adjusted Cox proportional hazards models of all-cause and lung cancer-specific mortality were assessed for lung cancer overall and by histotype.Results: Short telomere length was associated with increased mortality for small cell lung cancer (SCLC), particularly stage III/IV SCLC [HR and 95% confidence interval for shortest vs. longest telomere length tertile: 3.32 (1.78-6.21)]. Associations were strongest for those randomized to the active intervention and when telomere length was measured ≤5 years before diagnosis. All-cause mortality patterns were similar. Short chromosome 5p telomere length was suggestively associated with lung cancer mortality, but there was no association with chromosome 13q telomere length.Conclusions: Our large prospective study suggests that among heavy smokers who developed lung cancer, short prediagnosis telomere length is associated with increased risk of death from SCLC.Impact: This is the first study to examine telomere length and mortality in lung cancer cases by histotype. If the association between short telomere length and SCLC mortality is replicated, elucidation of mechanisms through which telomere length influences survival for this highly aggressive cancer may inform more effective use of telomere-targeted therapeutics. Cancer Epidemiol Biomarkers Prev; 27(7); 829-37. ©2018 AACR.

Nested case-control study of telomere length and lung cancer risk among heavy smokers in the β-Carotene and Retinol Efficacy Trial

Background

Telomeres protect cells from genomic instability. We examined telomere length and lung cancer risk prospectively in heavy smokers.

Methods

In a nested case–control study with 709 cases and 1313 controls, conditional logistic regression was used to evaluate associations between telomere length (global, chromosome 5p, and 13q) and lung cancer risk by histotype, controlling for detailed smoking history.

Results

Risks of overall lung cancer and adenocarcinoma were suggestively elevated among individuals with telomere length in the longest tertile. No clear patterns were observed for other histotypes, or for chromosome 5p or 13q telomere length. Associations with adenocarcinoma were strongest among (OR, 95% CI for longest versus shortest tertile): former smokers (2.26, 1.03–4.96), individuals <65 years (2.22, 1.13–4.35), and women (2.21, 0.99–4.93).

Conclusions

Our large study of heavy smokers adds additional evidence that long telomere length prior to diagnosis is associated with risk of lung adenocarcinoma, but not other histotypes.

Methods to adjust for misclassification in the quantiles for the generalized linear model with measurement error in continuous exposures

In many biomedical studies, covariates of interest may be measured with errors. However, frequently in a regression analysis, the quantiles of the exposure variable are often used as the covariates in the regression analysis. Because of measurement errors in the continuous exposure variable, there could be misclassification in the quantiles for the exposure variable. Misclassification in the quantiles could lead to bias estimation in the association between the exposure variable and the outcome variable. Adjustment for misclassification will be challenging when the gold standard variables are not available. In this paper, we develop two regression calibration estimators to reduce bias in effect estimation. The first estimator is normal likelihood-based. The second estimator is linearization-based, and it provides a simple and practical correction. Finite sample performance is examined via a simulation study. We apply the methods to a four-arm randomized clinical trial that tested exercise and weight loss interventions in women aged 50-75 years.

Effects of Vitamin D3 Supplementation on Lean Mass, Muscle Strength, and Bone Mineral Density During Weight Loss: A Double-Blind Randomized Controlled Trial

OBJECTIVES

To compare the effects of 12 months of vitamin D3 supplementation with that placebo on lean mass, bone mineral density (BMD), and muscle strength in overweight or obese postmenopausal women completing a structured weight-loss program.

DESIGN

Double-blind, placebo-controlled randomized clinical trial.

SETTING

Fred Hutchinson Cancer Research Center, Seattle, Washington.

PARTICIPANTS

Postmenopausal women aged 50 to 75 with a body mass index (BMI) of 25 kg/m(2) or greater and a serum 25-hydroxyvitamin D (25(OH)D) concentration between 10.0 and 32.0 ng/mL (insufficient) (N = 218).

INTERVENTION

Oral vitamin D3 2,000 IU/d or placebo in combination with a lifestyle-based weight loss intervention consisting of a reduction of 500 kcal to 1,000 kcal per day and 225 min/wk of moderate- to vigorous-intensity aerobic exercise.

MEASUREMENTS

Serum 25(OH)D, body composition, and muscle strength were measured before randomization (baseline) and at 12 months. Mean changes of the groups were compared (intention to treat) using generalized estimating equations.

RESULTS

Change in 25(OH)D was significantly different between the vitamin D and placebo groups at 12 months (13.6 ng/mL vs -1.3 ng/mL, P < .001), but no differences in change in lean mass (-0.8 kg vs -1.1 kg, P = .53) or BMD of the spine (-0.01 g/cm(2) vs 0.0 g/cm(2) , P = .82) or right femoral neck (both -0.01 g/cm(2) , P = .49) were detected between the groups. Leg strength decreased in the vitamin D group but not in the placebo group (-2.6 pounds vs 1.8 pounds, P = .03). In women randomized to vitamin D, achieving repletion (25(OH)D ≥ 32 ng/mL) did not alter results.

CONCLUSION

Vitamin D3 supplementation during weight-loss decreased leg strength but did not alter changes in lean mass or BMD in postmenopausal women with vitamin D insufficiency.

Abstract A68: Does genetic ancestry influence the metabolic response to a traditional Mexican versus U.S. diet? A randomized crossover feeding trial among first and second generation women of Mexican descent

Background: Greater acculturation to the U.S. dietary habits has been suggested to contribute to the high rates of obesity, insulin resistance, and therefore, potential risk of type 2 diabetes (T2D) and breast cancer. Mexican immigrants may be evolutionary adapted to traditional diets high in legumes and complex carbohydrates. When consuming an inexpensive, readily available U.S. diet high in refined carbohydrates and added sugars they may experience a detrimental metabolic and/or inflammatory response, placing them at a disproportionately higher risk of certain cancers. To better understand these biological mechanisms that may underlie immigrant-related health disparities, we tested whether genetic ancestry modified the metabolic response to a traditional Mexican versus U.S. diet in a controlled feeding trial.

Methods: First and second generation, female, Mexican immigrants (n=53) completed a randomized, crossover feeding trial testing the response to a Mexican versus U.S. diet for 24 days each, separated by a 28-day washout period. The trial diets were designed to provide energy content for weight maintenance and were similar in macronutrient composition. Participants were instructed to consume only study provided foods. The traditional Mexican diet was high in corn tortillas, beans, Mexican soups, fruits, vegetables, animal fats, full-fat milk, and Mexican cheeses; in contrast, the U.S. diet was high in refined carbohydrates, vegetable oils, nonfat or low-fat milk, processed foods, processed meats and sugar-sweetened beverages. The metabolic response to the diets was measured by fasting serum concentrations of glucose, insulin, insulin-like growth factor (IGF)-1, IGF binding protein (IGFBP)-3, adiponectin, C-reactive protein (CRP), interleukin-6 (IL-6), and the calculated homeostasis model assessment of insulin resistance (HOMA-IR) at the beginning and end of each feeding period. DNA was extracted from baseline blood for genotyping and estimation of each participant's proportion of genetic ancestry from four populations – Indigenous American (IA), European, African, and Asian – with the use of 218 Informative Ancestry Markers. Linear mixed models were adjusted for diet sequence, feeding period, baseline and washout biomarker concentrations, age, body weight, and acculturation.

Results: The overall genetic ancestral background of the study sample was 53% IA and 36% European ancestry. In general, genetic ancestry did not modify the metabolic responses to the Mexican versus U.S. diet. However, genetic ancestry was associated with some baseline participant's characteristics and measures. Greater IA ancestry trended toward a positive association with waist-to-hip ratio (P=0.08) and was inversely associated with both education and acculturation (P&lt;0.05). Further, greater IA ancestry was positively associated with baseline fasting serum concentrations of glucose, CRP, IL-6, and calculated HOMA-IR (P&lt;0.05), and was inversely associated with circulating concentrations of IGF-1 and IGFBP-3 (P&lt;0.05).

Conclusions: Genetic ancestry suggested differences in baseline measures of several biomarkers that have been identified as cancer susceptibility biomarkers. Although, we found a significant metabolic response to the traditional Mexican versus U.S. diet, overall, we did not observe correlations between genetic ancestry and this response. Nonetheless, the results from the study may inform our understanding of variation in cancer susceptibility biomarkers in vulnerable populations. Additional research is needed to further investigate whether genetic ancestry modifies the associations of other lifestyle exposures, such as physical activity or smoking, with cancer susceptibility biomarkers in Mexican immigrants and other minority groups.

Citation Format: Margarita Santiago-Torres, Jean De Dieu Tapsoba, Mario Kratz, Johanna W. Lampe, Kara L. Breymeyer, Lisa Levy, Xiaoling Song, Adriana Villaseñor, Ching-Yun Wang, Christopher Carlson, Marian L. Neuhouser. Does genetic ancestry influence the metabolic response to a traditional Mexican versus U.S. diet? A randomized crossover feeding trial among first and second generation women of Mexican descent. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr A68.

Metabolic responses to a traditional Mexican diet compared with a commonly consumed US diet in women of Mexican descent: a randomized crossover feeding trial

BACKGROUND

Mexican immigrants are disproportionally affected by diet-related risk of metabolic dysfunction. Whether adhering to a traditional Mexican diet or adopting a US diet contributes to metabolic changes associated with future risk of type 2 diabetes and other chronic diseases has not been investigated.

OBJECTIVE

The purpose of this study was to test in a randomized crossover feeding trial the metabolic responses to a Mexican diet compared with a commonly consumed US diet.

DESIGN

First- and second-generation healthy women of Mexican descent (n = 53) were randomly assigned in a crossover design to consume a Mexican or US diet for 24 d each, separated by a 28-d washout period. Diets were eucaloric and similar in macronutrient composition. The metabolic responses to diets were assessed by measuring fasting serum concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), adiponectin, C-reactive protein (CRP), and interleukin 6 (IL-6), as well as the homeostasis model assessment of insulin resistance (HOMA-IR) at the beginning and end of each period. Linear mixed models tested the intervention effect on the biomarkers, while adjusting for diet sequence, feeding period, baseline and washout biomarker concentrations, age, acculturation, and BMI.

RESULTS

Compared with the US diet, the Mexican diet reduced insulin by 14% [geometric means (95% CIs): 9.3 (8.3, 10.3) compared with 8.0 (7.2, 8.9) μU/mL; P = 0.02], HOMA-IR by 15% [2.0 (1.8, 2.3) compared with 1.7 (1.6, 2.0); P = 0.02], and IGFBP-3 by 6% (mean ± SEM: 2420 ± 29 compared with 2299 ± 29 ng/mL; P < 0.01) and tended to reduce circulating concentrations of IGF-1 by 4% (149 ± 2.6 compared with 144 ± 2.5 ng/mL; P = 0.06). There was no significant intervention effect on serum concentrations of glucose, adiponectin, CRP, or IL-6 in the US compared with the Mexican diet.

CONCLUSION

Compared with the commonly consumed US diet, the traditional Mexican diet modestly improved insulin sensitivity under conditions of weight stability in healthy women of Mexican descent, while having no impact on biomarkers of inflammation. This trial was registered at clinicaltrials.gov as NCT01369173.

Immunoglobulin genes and the acquisition of HIV infection in a randomized trial of recombinant adenovirus HIV vaccine

Our knowledge of the host genetic factors that contribute to the acquisition of HIV infection is limited. To identify the host genetic correlates of HIV1 acquisition, we genotyped 777 participants of a randomized trial of recombinant adenovirus HIV1 vaccine for Fcγ receptor IIa (FcγRIIa), FcγRIIIa, and several GM and KM alleles-genetic markers of immunoglobulin γ and κ chains, respectively. None of the genotypes by itself was significantly associated with the acquisition of HIV1 infection. However, particular combinations of GM and KM as well as those of GM and FcγRIIIa loci were significantly associated with the acquisition of HIV1 infection epistatically: KM1/3-GM3/17 (interaction p=0.0246; FDR=0.2952), KM1/3-GM5/21 (interaction p=0.0016; FDR=0.0960), and GM23+/-FcγRIIIa (interaction p=0.0060; FDR=0.1200). These results suggest the involvement of GM, KM, and FcγRIIIa loci in the acquisition of HIV infection. Additional studies are warranted.