The Dynamics of Apoptotic Cell Clearance.
Developmental Cell 38(2):147 (2016)
The phagocytic clearance of dying cells in a tissue is a highly orchestrated series of intercellular events coordinated by a complex signaling network. Recent data from genetic, biochemical, and live-imaging approaches have greatly enhanced our understanding of the dynamics of cell clearance and...
Validation of quasi-induced exposure representativeness assumption among young drivers.
Traffic Injury Prevention 17(4):346 (2016)
Young driver studies have applied quasi-induced exposure (QIE) methods to assess relationships between demographic and behavioral factors and at-fault crash involvement, but QIE's primary assumption of representativeness has not yet been validated among young drivers. Determining whether nonresp...
A two-step semiparametric method to accommodate sampling weights in multiple imputation.
Biometrics 72(1):242 (2016)
Multiple imputation (MI) is a well-established method to handle item-nonresponse in sample surveys. Survey data obtained from complex sampling designs often involve features that include unequal probability of selection. MI requires imputation to be congenial, that is, for the imputations to com...
Association between New Jersey's Graduated Driver Licensing decal provision and crash rates of young drivers with learners' permits.
Injury Prevention 21(6):421 (2015)
New Jersey (NJ) implemented the first-in-the-US Graduated Driver Licensing (GDL) decal provision in May 2010 for young drivers with learner's permits or intermediate licenses. Previous analyses found an association between the provision and crash reduction among intermediate drivers. The aim of ...
Accounting for sampling variability, injury under-reporting, and sensor error in concussion injury risk curves.
Journal of Biomechanics 48(12):3059 (2015)
There has been recent dramatic increase in the use of sensors affixed to the heads or helmets of athletes to measure the biomechanics of head impacts that lead to concussion. The relationship between injury and linear or rotational head acceleration measured by such sensors can be quantified wit...
Surrogacy assessment using principal stratification with multivariate normal and Gaussian copula models.
Clinical Trials 12(4):317 (2015)
The validation of intermediate markers as surrogate markers (S) for the true outcome of interest (T) in clinical trials offers the possibility for trials to be run more quickly and cheaply by using the surrogate endpoint in place of the true endpoint.
Working within a principal stratification fr...
Young driver crash rates by licensing age, driving experience, and license phase.
Accident Analysis & Prevention 80:243 (2015)
Few studies have concurrently assessed the influence of age and experience on young driver crashes, in particular in the post-Graduated Driver Licensing (GDL) era. Further, little attention is given to the transition from intermediate to full licensure. We examined the independent and joint cont...
Discussion of "On Bayesian Estimation of Marginal Structural Models".
Biometrics 71(2):288 (2015)
Joint modeling of cross-sectional health outcomes and longitudinal predictors via mixtures of means and variances.
Biometrics 71(2):487 (2015)
Joint modeling methods have become popular tools to link important features extracted from longitudinal data to a primary event. While most modeling strategies have focused on the association between the longitudinal mean trajectories and risk of an event, we consider joint models that incorpora...
Dynamics of health behaviours and socioeconomic differences in mortality in the USA.
Journal of Epidemiology & Community Health 69(5):416 (2015)
To measure the explanatory role of behavioural factors to educational and income disparities in mortality among US adults (ages 25+).
Data were from four waves of the American Changing Lives Study (N=3617). There were 1832 deaths between 1986 and 2011. Smoking, physical activity, alcohol and bod...
Surrogacy marker paradox measures in meta-analytic settings.
Biostatistics 16(2):400 (2015)
Because of the time and expense required to obtain clinical outcomes of interest, such as functional limitations or death, clinical trials often focus the effects of treatment on earlier and more easily obtained surrogate markers. Preliminary work to define surrogates focused on the fraction of ...
Young driver licensing: examination of population-level rates using New Jersey's state licensing database.
Accident Analysis & Prevention 76:49 (2015)
Recent surveys have provided insight on the primary reasons why US teens delay licensure but are limited in their ability to estimate licensing rates and trends. State administrative licensing data are the ideal source to provide this information but have not yet been analyzed for this purpose. ...
Influence of race/ethnicity, body mass index, and proximity of menopause on menstrual cycle patterns in the menopausal transition: the Study of Women's Health Across the Nation.
Menopause 22(2):159 (2015)
Few studies have evaluated factors that influence menstrual cycle length (MCL) during the menopausal transition (MT), a life stage during which very long cycles become more likely to occur. The objective of this article was to assess how body mass index and race/ethnicity--factors associated wit...
Long-term changes in crash rates after introduction of a Graduated Driver Licensing decal provision.
American Journal of Preventive Medicine 48(2):121 (2015)
New Jersey (NJ) implemented the first Graduated Driver Licensing (GDL) decal provision in the U.S. in May 2010. An initial study reported a 1-year post-decal decrease in the crash rate among NJ intermediate drivers aged <21 years. Longer-term analysis is critical for policymakers in other states...
Engagement with the TeenDrivingPlan and diversity of teens' supervised practice driving: lessons for internet-based learner driver interventions.
Injury Prevention 21(1):4 (2015)
Inexperienced, less-skilled driving characterises many newly licensed drivers and contributes to high crash rates. A randomised trial of TeenDrivingPlan (TDP), a new learner driver phase internet-based intervention, demonstrated effectiveness in improving safety relevant, on-road driving behavio...
Joint modeling compliance and outcome for causal analysis in longitudinal studies.
Statistics in Medicine 33(20):3453 (2014)
This article discusses joint modeling of compliance and outcome for longitudinal studies when noncompliance is present. We focus on two-arm randomized longitudinal studies in which subjects are randomized at baseline, treatment is applied repeatedly over time, and compliance behaviors and clinic...
Effect of the teen driving plan on the driving performance of teenagers before licensure: a randomized clinical trial.
JAMA Pediatrics 168(8):764 (2014)
Many studies have failed to show an effect of parent-supervised practice driving on the driving performance of teenagers; nevertheless, most Graduated Driver Licensing programs have provisions that require supervised practice.
To determine whether a web-based intervention, the Teen Driving Plan ...
Essential role of Elmo1 in Dock2-dependent lymphocyte migration.
Journal of Immunology 192(12):6062 (2014)
Elmo1 and Elmo2 are highly homologous cytoplasmic adaptor proteins that interact with Dock family guanine nucleotide exchange factors to promote activation of the small GTPase Rac. In T lymphocytes, Dock2 is essential for CCR7- and CXCR4-dependent Rac activation and chemotaxis, but the role of E...
Statistical implications of using moving violations to determine crash responsibility in young driver crashes.
Accident Analysis & Prevention 65:28 (2014)
Traditional methods for determining crash responsibility - most commonly moving violation citations - may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these ...
Surrogacy assessment using principal stratification when surrogate and outcome measures are multivariate normal.
Biostatistics 15(2):266 (2014)
In clinical trials, a surrogate outcome variable (S) can be measured before the outcome of interest (T) and may provide early information regarding the treatment (Z) effect on T. Using the principal surrogacy framework introduced by Frangakis and Rubin (2002. Principal stratification in causal i...