Ron Brookmeyer's research while affiliated with Department of Public Health - Los Angeles County and other places

Publications (200)

Article
The COVID-19 pandemic has underscored the importance of observational studies of real-world vaccine effectiveness to help answer urgent public health questions. One approach to rapidly answering questions about real-world vaccine effectiveness relies on linking data from a population-based registry of vaccinations with a population-based registry o...
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Understanding non-communicable diseases (NCDs) among young people living with HIV (YLWH) is critical given the potential for aging-associated comorbidities resulting from HIV, especially in Cambodia where such data are limited. Therefore, we examined the prevalence and correlates of NCDs in YLWH and compared it to a nationally representative sample...
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Introduction: Some evidence suggests that neighborhood socioeconomic disadvantage is associated with dementia-related outcomes. However, prior research is predominantly among non-Latino Whites. Methods: We evaluated the association between neighborhood disadvantage (Area Deprivation Index [ADI]) and dementia incidence in Asian American (n = 18,1...
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Introduction: Literature shows lower dementia incidence in Asian American groups versus whites, varying by Asian ethnicity. One hypothesized driver is nativity differences (eg, healthy immigrant effect). Methods: We followed a cohort of 6243 Chinese, 4879 Filipino, 3256 Japanese, and 141,158 white Kaiser Permanente Northern California members fo...
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A method for generalized linear regression with interval‐censored covariates is described, extending previous approaches. A scenario is considered in which an interval‐censored covariate of interest is defined as a function of other variables. Instead of directly modeling the distribution of the interval‐censored covariate of interest, the distribu...
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While randomized trials remain the best evidence for treatment effectiveness, lack of generalizability often remains an important concern. Additionally, when new treatments are compared against existing standards of care, the potentially small benefit of the new treatment may be difficult to detect in a trial without extremely large sample sizes an...
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Importance Dementia research is susceptible to bias arising from selective survival, a process that results in individuals with certain characteristics disproportionately surviving to old age. Spurious associations between risk factors and dementia may be induced when factors associated with longer survival also influence dementia incidence. Objec...
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Background Substance use decreases the likelihood of achieving undetectable HIV viremia; however, the comparative effects by drug have not been fully described. In this study, we compare the effects of methamphetamine use versus other drugs on viremia in sexual minority men on antiretroviral therapy (ART). Methods HIV-positive participants current...
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For men who have sex with men (MSM) in the US, the positive and negative aspects of social capital – access to resources within their social networks and experiences of homophobia – may explain their disproportionate burden of HIV infection. We analyzed data from 379 HIV seronegative and seropositive MSM in Los Angeles, collected between May 2017 a...
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Objectives: The prevalence of obesity is rising among people living with HIV, which may synergistically increase inflammation and the risk of associated diseases. Disruption of gut bacterial communities may be one of the key drivers of this inflammation; however, the combined effects of HIV and obesity on the microbiome have not been explored. Me...
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Background: The objective of this study was to examine depressive symptoms overtime and quantify the variance in symptoms attributable to substance use among a cohort of HIV-positive and HIV-negative men. Methods: Participants were enrolled in an NIH/NIDA funded cohort, with 534 men resulting in 1,888 visits between August 2014 and June 2018. Pa...
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Methamphetamine (MA) use is a major public health problem in the United States, especially among people living with HIV (PLWH). Many MA-induced neurotoxic effects are mediated by inflammation and gut microbiota may play a role in this process, yet the effects of MA on the microbiome have not been adequately explored. Therefore, we performed 16S rRN...
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Dramatic decreases in HIV transmission are achievable with currently available biomedical and behavioral interventions, including antiretroviral therapy and pre-exposure prophylaxis. However, such decreases have not yet been realized among adolescents and young adults. The Adolescent Medicine Trials Network (ATN) for HIV/AIDS interventions is dedic...
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Public health emergencies, such as an Ebola disease outbreak, provide a complex and challenging environment for the evaluation of candidate vaccines. Here, we outline the need for flexible and responsive vaccine trial designs to be used in public health emergencies, and we summarize recommendations for their use in this setting.
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The cross‐sectional approach to HIV incidence estimation overcomes some of the challenges with longitudinal cohort studies and has been successfully applied in many settings around the world. However, the cross‐sectional approach does rely on an initial training data set to develop and calibrate the statistical methods to be used in cross‐sectional...
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Background Why some persons living with human immunodeficiency virus (HIV) (PLWH) progress quickly and others remain “healthy” for a decade or more without treatment remains a fundamental question of HIV pathology. We aimed to assess the epidemiological characteristics of HIV long-term nonprogressors (LTNPs) based on a cohort of PLWH in China obser...
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Estimation of the proportion of living HIV-infected persons that have been diagnosed is critical for tracking progress toward meeting the UNAIDS goal that all persons who need HIV treatment receive it. The objective of this article is to develop a method for estimating that proportion. The methodological problem is that persons with undiagnosed HIV...
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Clinical trials for Alzheimer’s disease have been aimed primarily at persons who have cognitive symptoms at enrollment. However, researchers are now recognizing that the pathophysiological process of Alzheimer’s disease begins years, if not decades, prior to the onset of clinical symptoms. Successful intervention may require intervening early in th...
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Objective: We employed a high-dimensional covariate adjustment method in microbiome analysis to better control for behavioural and clinical confounders, and in doing so examine the effects of HIV on the rectal microbiome. Design: Three hundred and eighty-three MSM were grouped into four HIV viremia categories: HIV negative (n = 200), HIV-positiv...
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This study evaluates HIV antibody responses and their evolution during the course of HIV infection. A phage display system is used to characterize antibody binding to >3,300 HIV peptides in 57 adults with early- to late-stage infection. We find that the number of unique epitopes targeted (“antibody breadth”) increases early in infection and then st...
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The lifetime risk of a clinical condition is the probability of onset of the condition during one's lifespan. Recent advances in Alzheimer's disease (AD) research have identified screening tests for biomarkers that can identify persons who are in the earliest stages of the AD process but who do not yet have any clinical signs or symptoms. A critica...
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Objective The degree to which Alzheimer's versus other neuropathologies contribute to the risk of Alzheimer's dementia is unknown. We examined the risk of Alzheimer's dementia attributable to pathologic AD and eight other neuropathologies. Methods Participants (n=1,161) came from two clinical‐pathologic studies of aging. Multivariable logistic reg...
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For individuals living with human immunodeficiency virus (HIV), viral suppression positively affects quality and length of life and reduces risks for HIV transmission. Men of color who have sex with men (MoCSM) who have been diagnosed with HIV have disproportionately low rates of viral suppression, with concomitant increases in incidence. We identi...
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Considerable progress has been made in the development of approaches for HIV incidence estimation based on a cross-sectional survey for biomarkers of recent infection. Multiple biomarkers when used in combination can increase the precision of cross-sectional HIV incidence estimates. Multi-assay algorithms (MAAs) for cross-sectional HIV incidence es...
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Background: People living with HIV (PLWH) are still being diagnosed late, rendering the benefits of "early" antiretroviral therapy (ART; based on CD4 count) unattainable. Therefore, we aimed to evaluate the benefits of "immediate" ART (based on the time interval between diagnosis and treatment, regardless of CD4 count). Methods: A nationwide coh...
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Introduction: Lifetime risks are the probabilities of progressing to Alzheimer's disease (AD) dementia during one's lifespan. Here, we report the first estimates of the lifetime and ten-year risks of AD dementia based on age, gender, and biomarker tests for preclinical disease. Methods: We used a multistate model for the disease process together...
Preprint
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Public Health Emergencies (PHEs) provide a complex and challenging environment for vaccine evaluation. Under the R&D Blueprint Plan of Action, the World Health Organization (WHO) has convened a group of experts to agree on standard procedures to rapidly evaluate experimental vaccines during PHEs while maintaining the highest scientific and ethical...
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Background: Methamphetamine use increases the risk of HIV-1 infection among seronegative users, and can exacerbate disease progression in HIV-positive users. The biological mechanisms underlying these associations remain unclear. In this cross-sectional pilot study, we examine the associations between recent methamphetamine use and inflammation in...
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Introduction: We forecast the prevalence of preclinical and clinical Alzheimer's disease (AD) and evaluated potential impacts of primary and secondary preventions in the United States. Methods: We used a multistate model incorporating biomarkers for preclinical AD with US population projections. Results: Approximately 6.08 million Americans ha...
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Background: Interventions in infectious diseases can have both direct effects on individuals who receive the intervention as well as indirect effects in the population. In addition, intervention combinations can have complex interactions at the population level, which are often difficult to adequately assess with standard study designs and analyti...
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Multistate models provide an important method for analyzing a wide range of life history processes including disease progression and patient recovery following medical intervention. Panel data consisting of the states occupied by an individual at a series of discrete time points are often used to estimate transition intensities of the underlying co...
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Background: Clinical trials have demonstrated that immediate initiation of antiretroviral therapy (ART) reduces AIDS-related morbidity and mortality. We tested the hypothesis that initiating ART ≤30 days after HIV diagnosis would be associated with reduced mortality among people living with HIV (PLWH) with CD4 counts >500 cells/mm3. Methods: PLW...
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Here we urge the adoption of a new paradigm for the design and interpretation of intervention trials in infectious diseases, particularly in emerging infectious disease, that more accurately reflects the dynamics of the transmission process. Interventions in infectious diseases can have indirect effects on those not receiving the intervention as we...
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Objective Investments have been made to alter the food environment of neighbourhoods that have a disproportionate number of unhealthy food venues. Corner store conversions are one strategy to increase access to fruits and vegetables (F&V). Although the literature shows modest success, the effectiveness of these interventions remains equivocal. The...
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Introduction: We investigated the association between age of onset of hypertension and dementia risk in an oldest-old cohort. Methods: Participants are from The 90+ Study, a population-based longitudinal study of people aged 90+ who are survivors from the Leisure World Cohort Study. We estimated hypertension onset age using self-reported informa...
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Background: The employment of professional interviewers from academic survey centers to conduct surveys has been standard practice. Because one goal of community-engaged research is to provide professional skills to community residents, this paper considers whether employing locally trained lay interviewers from within the community may be as effe...
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Understanding the impact of concurrency, defined as overlapping sexual partnerships, on the spread of HIV within various communities has been complicated by difficulties in measuring concurrency. Retrospective sexual history data consisting of first and last dates of sexual intercourse for each previous and ongoing partnership is often obtained thr...
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Background The effectiveness of food retail interventions is largely undetermined, yet substantial investments have been made to improve access to healthy foods in food deserts and swamps via grocery and corner store interventions. This study evaluated the effects of corner store conversions in East Los Angeles and Boyle Heights, California on perc...
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Introduction HIV incidence is an important measure for monitoring the development of the epidemic, but it is difficult to ascertain. We combined serial HIV prevalence and mortality data to estimate HIV incidence among key affected populations (KAPs) in China. Methods Serial cross-sectional surveys were conducted among KAPs from 2010 to 2014. Trend...
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Introduction: The number of persons aged >90 years will grow significantly in coming decades. This group has the highest rates of dementia, most commonly Alzheimer's disease (AD). Methods: Using the 90+ Study, we developed a statistical model for dementia risk based on brain pathologies. Intervention scenarios which reduce or eliminate AD pathol...
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Background: Multistage stepwise HIV testing and treatment initiation procedures can result in lost opportunities to provide timely antiretroviral therapy (ART). Incomplete patient engagement along the continuum of HIV care translates into high levels of preventable mortality. We aimed to evaluate the ability of a simplified test and treat structur...
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Understanding HIV incidence, the rate at which new infections occur in populations, is critical for tracking and surveillance of the epidemic. In this article, we derive methods for determining sample sizes for cross-sectional surveys to estimate incidence with sufficient precision. We further show how to specify sample sizes for two successive cro...
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Cardiovascular disease (CVD) is the leading killer of Americans. CVD is understudied among Latinos, who have high levels of CVD risk factors. This study aimed to determine whether access to health care (ie, insurance status and having a usual source of care) is associated with 4 CVD prevention factors (ie, health care utilization, CVD screening, in...
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HIV prevention trials have demonstrated the effectiveness of a number of behavioral and biomedical interventions. HIV prevention packages are combinations of interventions and offer potential to significantly increase the effectiveness of any single intervention. Estimates of the effectiveness of prevention packages are important for guiding the de...
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Background: Human immunodeficiency virus (HIV) prevention intervention programs and related research for men who have sex with men (MSM) in the southern African region remain limited, despite the emergence of a severe epidemic among this group. With a lack of understanding of their social and sexual lives and HIV risks, and with MSM being a hidden...
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Important sources of variation in the spread of HIV in communities arise from overlapping sexual networks and heterogeneity in biological and behavioral risk factors in populations. These sources of variation are not routinely accounted for in the design of HIV prevention trials. In this paper, we use agent-based models to account for these sources...
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Urban food swamps are typically situated in low-income, minority communities and contribute to overweight and obesity. Changing the food landscape in low income and underserved communities is one strategy to combat the negative health consequences associated with the lack of access to healthy food resources and an abundance of unhealthy food venues...
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The performance of diagnostic tests for disease classification is often measured by accuracy (e.g., sensitivity or specificity); however, costs of the diagnostic test are a concern as well. Combinations of multiple diagnostic tests may improve accuracy, but incur additional costs. Here, we consider serial testing approaches that maintain accuracy w...
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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 d...
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Previous studies have established that acculturation is associated with dietary intake among Mexican immigrants and their offspring, but few studies have investigated whether food purchasing, food preparation or food-related values act as mechanisms of dietary acculturation. We examine the relationship between language use and a wide range of food...
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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. Performance of testing algorithms was evaluated using 2,282 samples from individ...
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Introduction: An increasingly popular strategy to improving the food retail environment and promoting healthy eating in low-income and minority communities is the corner store conversion. This approach involves partnering with small 'corner' food stores to expand access to high-quality fruits, vegetables, and other healthy foods. Methods: We con...
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Multi-assay algorithms (MAAs) can be used for cross-sectional HIV incidence estimation. We previously identified a robust MAA that includes the BED capture immunoassay (BED-CEIA), the BioRad-Avidity assay, viral load, and CD4 cell count. In this report, we evaluated MAAs that include a high resolution melting (HRM) diversity assay that does not req...
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Accurate methods for estimating HIV incidence from cross-sectional samples would have great utility in prevention research. This report describes recent improvements in cross-sectional methods that significantly improve their accuracy. These improvements are based on the use of multiple biomarkers to identify recent HIV infections. These multiassay...
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Background: Assays to determine HIV incidence from cross-sectional surveys have exhibited a high rate of false-recent misclassification in Kenya and Uganda where HIV subtypes A and D predominate. Methods: Samples from individuals infected with HIV for at least 2 years with known infecting subtype (133 subtype A, 373 subtype D) were tested using the...
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Viral suppression and viral breakthrough impact the humoral immune response to HIV infection. We evaluated the impact of viral suppression and viral breakthrough on results obtained with two cross-sectional HIV incidence assays. All samples were collected from adults in the US who were HIV infected for >2 years. Samples were tested with the BED cap...
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The incidence of human immunodeficiency virus (HIV) is the rate at which new HIV infections occur in populations. The development of accurate, practical, and cost-effective approaches to estimation of HIV incidence is a priority among researchers in HIV surveillance because of limitations with existing methods. In this paper, we develop methods for...
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Objective: To compare student outcomes between concurrent online and on-campus sections of an introductory biostatistics course offered at a United States school of public health in 2005. Methods: Enrolled students (95 online, 92 on-campus) were invited to participate in a confidential online survey. The course outcomes were compared between the...
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The association between immigration status and cardiovascular disease (CVD) risk factor awareness is unknown. Using physical examination-based data and participants' self-report of prior diagnosis, we assessed immigration-based disparities in awareness of diabetes, hypertension, hypercholesterolemia, and overweight among 12,124 participants in the...
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Background: Accurate testing algorithms are needed for estimating human immunodeficiency virus (HIV) incidence from cross-sectional surveys. Methods: We developed a multiassay algorithm (MAA) for HIV incidence that includes the BED capture enzyme immunoassay (BED-CEIA), an antibody avidity assay, HIV load, and CD4(+) T-cell count. We analyzed 17...
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Background. Reliable methods for estimating the incidence of human immunodeficiency virus (HIV) infection are needed to monitor the epidemic, identify at-risk populations, and evaluate HIV prevention strategies. We used a multifaceted approach to estimate HIV incidence in the HIV Prevention Trials Network (HPTN) 064 study. Methods. The HPTN 064 stu...