Characteristics of the MACS/WIHS Combined Cohort Study: Opportunities for Research on Aging With HIV in the Longest US Observational Study of HIV
AbstractIn 2019, the National Institutes of Health combined the Multicenter AIDS Cohort Study (MACS) and the Women ’s Interagency HIV Study (WIHS) into the MACS/WIHS Combined Cohort Study (MWCCS). In this paper, participants who made a study visit during October 2018–September 2019 (targeted for MWCCS enrollment) are described by human immunodeficiency virus (HIV) serostatus and compared with people living w ith HIV (PLWH) in the United States. Participants include 2,115 women and 1,901 men with a median age of 56 years (interquartile range, 48–63); 62% are PLWH. Study sites encompass the South (18%), the Mid-Atlanti...
Source: American Journal of Epidemiology - March 2, 2021 Category: Epidemiology Source Type: research
Life-Course Socioeconomic Status and Risk of Hospitalization for Heart Failure or Atrial Fibrillation in the Moli-sani Study Cohort
In conclusion, a life-course–disadvantaged SES is an important predictor of first hospitalization fo r HF and AF; known risk factors partially explained the SES–disease gradient. Being in an upwardly mobile group is likely to mitigate the effect of poor childhood circumstances, especially through educational advancement. (Source: American Journal of Epidemiology)
Source: American Journal of Epidemiology - February 24, 2021 Category: Epidemiology Source Type: research
Re: “the clinical course of coronavirus disease 2019 in a us hospital system: a multistate analysis”
We congratulate Mody et al. (1) on their sophisticated multistate analysis of 1,577 hospitalized patients with coronavirus disease 2019 (COVID-19) in a regional US hospital system. Multistate models allow for a detailed investigation of the course of disease while importantly avoiding severe, yet common, types of bias (2). (Source: American Journal of Epidemiology)
Source: American Journal of Epidemiology - February 22, 2021 Category: Epidemiology Source Type: research
Transporting Subgroup Analyses of Randomized Controlled Trials for Planning Implementation of New Interventions
AbstractSubgroup analyses of randomized controlled trials guide resource allocation and implementation of new interventions by identifying groups of individuals who are likely to benefit most from the intervention. Unfortunately, trial populations are rarely representative of the target populations of public health or clinical interest. Unless the relevant differences between trial and target populations are accounted for, subgroup results from trials might not reflect which groups in the target population will benefit most from the intervention. Transportability provides a rigorous framework for applying results derived i...
Source: American Journal of Epidemiology - February 22, 2021 Category: Epidemiology Source Type: research
Propensity Score Weighting and Trimming Strategies for Reducing Variance and Bias of Treatment Effect Estimates: A Simulation Study
AbstractTo extend previous simulations on the performance of propensity score (PS) weighting and trimming methods to settings without and with unmeasured confounding, Poisson outcomes, and various strengths of treatment prediction (PSc statistic), we simulated studies with a binary intended treatmentT as a function of 4 measured covariates. We mimicked treatment withheld and last-resort treatment by adding 2 “unmeasured” dichotomous factors that directed treatment to change for some patients in both tails of the PS distribution. The number of outcomesY was simulated as a Poisson function ofT and confounders. We estimat...
Source: American Journal of Epidemiology - February 22, 2021 Category: Epidemiology Source Type: research
Invited Commentary: Treatment Drop-in —Making the Case for Causal Prediction
AbstractClinical prediction models (CPMs) are often used to guide treatment initiation, with individuals at high risk offered treatment. This implicitly assumes that the probability quoted from a CPM represents the risk to an individual of an adverse outcome in absence of treatment. However, for a CPM to correctly target this estimand requires careful causal thinking. One problem that needs to be overcome is treatment drop-in: where individuals in the development data commence treatment after the time of prediction but before the outcome occurs. In this issue of theJournal, Xu et al. (Am J Epidemiol. 2021;190(10):2000 –2...
Source: American Journal of Epidemiology - February 17, 2021 Category: Epidemiology Source Type: research
Prediction of Cardiovascular Disease Risk Accounting for Future Initiation of Statin Treatment
In conclusion, incorporating statin effects from trial results into risk-prediction models enables statin-naive CVD risk estimation and provides moderate gains in predictive ability but had a limited impact on treatment decision- making under current guidelines in this population. (Source: American Journal of Epidemiology)
Source: American Journal of Epidemiology - February 17, 2021 Category: Epidemiology Source Type: research
Early-Life Socioeconomic Position and the Accumulation of Health-Related Deficits by Midlife in the 1958 British Birth Cohort Study
AbstractReducing population levels of frailty is an important goal, and preventing its development in midadulthood could be pivotal. There is limited evidence on associations between childhood socioeconomic position (SEP) and frailty. Using data on the 1958 British birth cohort (followed from 1958 to 2016;n = 8,711), we aimed to 1) establish the utility of measuring frailty in midlife, by examining associations between a 34-item frailty index at age 50 years (FI50y) and mortality at ages 50 –58 years, and 2) examine associations between early-life SEP and FI50y and investigate whether these associations were explained ...
Source: American Journal of Epidemiology - February 17, 2021 Category: Epidemiology Source Type: research
Emulating Target Trials to Improve Causal Inference From Agent-Based Models
AbstractAgent-based models are a key tool for investigating the emergent properties of population health settings, such as infectious disease transmission, where the exposure often violates the key “no interference” assumption of traditional causal inference under the potential outcomes framework. Agent-based models and other simulation-based modeling approaches have generally been viewed as a separate knowledge-generating paradigm from the potential outcomes framework, but this can lead t o confusion about how to interpret the results of these models in real-world settings. By explicitly incorporating the target trial...
Source: American Journal of Epidemiology - February 17, 2021 Category: Epidemiology Source Type: research
Simulation in practice: the balancing intercept
Simulation is an important tool within epidemiology for both learning and developing new methodology (1–5). Unfortunately, few epidemiology training programs teach basic simulation methods. Briefly, when conducting a simulation experiment, we generally follow the same basic steps. We first decide which variables to include, as well as their distributions and associations —often aided by a causal diagram. We then generate those variables by sampling from their specified distributions and estimate whatever target parameter is of interest (e.g., sample average or causal effect). We finally repeat the process multiple time...
Source: American Journal of Epidemiology - February 17, 2021 Category: Epidemiology Source Type: research
Health-Care Utilization Due to Suicide Attempts Among Homeless Youth in New York State
AbstractSuicide remains the leading cause of death among homeless youth. We assessed differences in health-care utilization between homeless and nonhomeless youth presenting to the emergency department or hospital after a suicide attempt. New York Statewide Inpatient and Emergency Department Databases (2009 –2014) were used to identify homeless and nonhomeless youth aged 10–17 who utilized health-care services following a suicide attempt. To evaluate associations with homelessness, we used logistic regression models for use of violent means, intensive care unit utilization, log-transformed linear r egression models for...
Source: American Journal of Epidemiology - February 12, 2021 Category: Epidemiology Source Type: research
The Impact of Same-Day Antiretroviral Therapy Initiation Under the World Health Organization Treat-All Policy
AbstractRapid initiation of antiretroviral therapy (ART) is recommended for people living with human immunodeficiency virus (HIV), with the option to start treatment on the day of diagnosis (same-day ART). However, the effect of same-day ART remains unknown in realistic public sector settings. We established a cohort of ≥16-year-old patients who initiated first-line ART under a treat-all policy in Nhlangano (Eswatini) during 2014–2016, either on the day of HIV care enrollment (same-day ART) or 1–14 days thereafter (early ART). Directed acyclic graphs, flexible parametric survival analysis, and targeted maximu m likel...
Source: American Journal of Epidemiology - February 12, 2021 Category: Epidemiology Source Type: research
Comparing Parametric, Nonparametric, and Semiparametric Estimators: The Weibull Trials
AbstractWe use simple examples to show how the bias and standard error of an estimator depend in part on the type of estimator chosen from among parametric, nonparametric, and semiparametric candidates. We estimated the cumulative distribution function in the presence of missing data with and without an auxiliary variable. Simulation results mirrored theoretical expectations about the bias and precision of candidate estimators. Specifically, parametric maximum likelihood estimators performed best but must be “omnisciently” correctly specified. An augmented inverse probability–weighted (IPW) semiparametric estimator p...
Source: American Journal of Epidemiology - February 11, 2021 Category: Epidemiology Source Type: research
Associations of Lifestyle and Anthropometric Factors With the Risk of Herpes Zoster: A Nationwide Population-Based Cohort Study
We examined whether smoking status, alcohol consumption, body mass index, or physical activity were associated with zoster risk. We followed a population-based cohort of 101,894 respondents to the 2010 Danish National Health Survey (baseline, May 1, 2010) until zoster diagnosis, death, emigration, or July 1, 2014, whichever occurred first. We computed hazard ratios for zoster associated with each exposure, using Cox regression with age as the time scale and adjusting for potential confounders. Compared with never smokers, hazards for zoster were increased in former smokers (1.17, 95% confidence interval (CI): 1.06, 1.30), ...
Source: American Journal of Epidemiology - February 11, 2021 Category: Epidemiology Source Type: research
Biases in Evaluating the Safety and Effectiveness of Drugs for the Treatment of COVID-19: Designing Real-World Evidence Studies
AbstractThe coronavirus disease 2019 pandemic, which was caused by the severe acute respiratory syndrome coronavirus 2, has led to an unprecedented effort to generate real-world evidence on the safety and effectiveness of various treatments. A growing number of observational studies in which the effects of certain drugs were evaluated have been conducted, including several in which researchers assessed whether hydroxychloroquine improved outcomes in infected individuals and whether renin-angiotensin-aldosterone system inhibitors have detrimental effects. In the present article, we review and illustrate how immortal time bi...
Source: American Journal of Epidemiology - February 10, 2021 Category: Epidemiology Source Type: research
