ESTIMATING THE CONDITIONAL HAZARD FUNCTION OF JOINT LATENT CLASS MIXED MODELS USING HAZARD REGRESSION WITH APPLICATIONS TO PSYCHOLOGY AND NEUROSCIENCE

Research within the fields psychology and neuroscience often have interest in estimating the change of a latent variable over repeated measurements. While the inference of interest lies within this latent variable, observed variables that express this latent variable are instead measured. If the latent variable is observed by a change in a specific biomarker as well as the time-to-event, then a joint model may be more suitable for estimating the change of the latent variable than a typical single-model approach. Given a heterogeneous sample comprising a mixture of classes of this latent variable, a joint latent class mixed model may prove effective.Within this joint model, the Cox proportional hazards model is a popular choice for modeling the time-to-event due to its robustness and minimal assumptions. However, the Cox model still requires a proportionality assumption. Hazard regression (HARE) was developed with relaxing this assumption in mind. HARE uses an adaptive B-spline method to estimate the conditional log-hazard function of the survival model not requiring that the hazard function follow this proportionality assumption. The B-splines in HARE can take the form of covariates of interest, time, or a tensor product of the two. An adaptive regression method estimates the conditional log-hazard function via a partial likelihood method.The purpose of this proposal is to introduce the HARE methodology to estimating the class-specific conditional log-hazard function of a joint latent class mixed model with applications to psychology and neuroscience research. This method is then tested on a study of simulated data, on a subset of data from the Paquid longitudinal cohort study, data from an experiment assessing visual information from infants as they engage in a social arousal task, and longitudinal data from the Infant Brain Imaging Study. The novelty and utility of HARE within the joint latent class mixed model are explored and discussed.Doctor of Public Healt

Longitudinal Study of Body Mass Index in Young Males and the Transition to Fatherhood.

Despite a growing understanding that the social determinants of health have an impact on body mass index (BMI), the role of fatherhood on young men's BMI is understudied. This longitudinal study examines BMI in young men over time as they transition from adolescence into fatherhood in a nationally representative sample. Data from all four waves of the National Longitudinal Study of Adolescent Health supported a 20-year longitudinal analysis of 10,253 men beginning in 1994. A "fatherhood-year" data set was created and changes in BMI were examined based on fatherhood status (nonfather, nonresident father, resident father), fatherhood years, and covariates. Though age is positively associated with BMI over all years for all men, comparing nonresident and resident fathers with nonfathers reveals different trajectories based on fatherhood status. Entrance into fatherhood is associated with an increase in BMI trajectory for both nonresident and resident fathers, while nonfathers exhibit a decrease over the same period. In this longitudinal, population-based study, fatherhood and residence status play a role in men's BMI. Designing obesity prevention interventions for young men that begin in adolescence and carry through young adulthood should target the distinctive needs of these populations, potentially improving their health outcomes

Adolescent Reproductive Knowledge, Attitudes, and Beliefs and Future Fatherhood.

PurposeWith a growing focus on the importance of men's reproductive health, including preconception health, the ways in which young men's knowledge, attitudes, and beliefs (KAB) predict their reproductive paths are understudied. To determine if reproductive KAB predicts fatherhood status, timing and residency (living with child or not).MethodsReproductive KAB and fatherhood outcomes were analyzed from the National Longitudinal Study of Adolescent Health, a 20-year, nationally representative study of individuals from adolescence into adulthood. Four measures of reproductive KAB were assessed during adolescence in waves I and II. A generalized linear latent and mixed model predicted future fatherhood status (nonfather, resident/nonresident father, adolescent father) and timing while controlling for other socio-demographic variables.ResultsOf the 10,253 men, 3,425 were fathers (686 nonresident/2,739 resident) by wave IV. Higher risky sexual behavior scores significantly increased the odds of becoming nonresident father (odds ratio [OR], 1.30; p < .0001), resident father (OR, 1.07; p = .007), and adolescent father (OR, 1.71; p < .0001); higher pregnancy attitudes scores significantly increased the odds of becoming a nonresident father (OR, 1.20; p < .0001) and resident father (OR, 1.11; p < .0001); higher birth control self-efficacy scores significantly decreased the odds of becoming a nonresident father (OR, .72; p < .0001) and adolescent father (OR, .56; p = .01).ConclusionsYoung men's KAB in adolescence predicts their future fatherhood and residency status. Strategies that address adolescent males' reproductive KAB are needed in the prevention of unintended reproductive consequences such as early and nonresident fatherhood

Diamantes do médio rio Jequitinhonha, Minas Gerais: qualificação gemológica e análise granulométrica

BackgroundGlobal health measures represent an attractive option for researchers and clinicians seeking a brief snapshot of a patient's overall perspective on his or her health. Because scores on different global health measures are not comparable, comparative effectiveness research (CER) is challenging.ObjectiveTo establish a common reporting metric so that the physical and mental health scores on the Veterans RAND 12-Item Health Survey (VR-12 (©) ) can be converted into scores on the corresponding Patient Reported Outcomes Measurement Information System (PROMIS(®)) Global Health scores.DesignFollowing a single-sample linking design, participants from an Internet panel completed items from the PROMIS Global Health and VR-12 Health Survey. A common metric was created using analyses based on item response theory (IRT), producing score cross-walk tables for the mental and physical health components of each measure. The linking relationships were evaluated by calculating the standard deviation of differences between the observed and linked PROMIS scores and estimating confidence intervals by sample size.ParticipantsParticipants (N = 2025) were 49 % male and 73 % white; mean age was 46 years.Main measuresMental and physical health subscales of the PROMIS Global Health and the VR-12. The mean VR-12 physical component and mental component scores were 45.2 and 46.6, respectively; the mean PROMIS physical and mental health scores were 48.3 and 48.5, respectively.Key resultsWe found evidence that the combined set of VR-12 and PROMIS items were relatively unidimensional and that we could proceed with linking. Linking worked better between the physical health than mental health scores using VR-12 item responses (vs. linking based on algorithmic scores). For each of the cross-walks, users can minimize the impact of linking error with modest increases in sample sizes.ConclusionsVR-12 scores can be expressed on the PROMIS Global Health metric to facilitate the evaluation of treatment, including CER. Extending these results to other common measures of global health is encouraged

Personality Predicts Mortality Risk: An Integrative Data Analysis of 15 International Longitudinal Studies

This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR<1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research.Funding support for this project was provided by the National Institute on Aging: P01-AG043362 (Integrative Analysis of Longitudinal Studies of Aging (IALSA), [Scott M. Hofer (PI)]), and Daniel K. Mroczek (CoInvestigator and Project Leader of the IALSA Personality & Health Project, as well as R01-AG018436 [Personality & Well-Being Trajectories in Adulthood, Daniel K. Mroczek, PI])

A longitudinal study of paternal mental health during transition to fatherhood as young adults.

Background and objectiveRates of paternal depression range from 5% to 10% with a growing body of literature describing the harm to fathers, children, and families. Changes in depression symptoms over the life course, and the role of social factors, are not well known. This study examines associations with changes in depression symptoms during the transition to fatherhood for young fathers and whether this association differed by key social factors.MethodsWe combined all 4 waves of the National Longitudinal Study of Adolescent Health to support a 23-year longitudinal analysis of 10 623 men and then created a "fatherhood-year" data set, regressing age-adjusted standardized depressive symptoms scores on fatherhood status (nonresidence/residence), fatherhood-years, and covariates to determine associations between Center for Epidemiologic Studies Depression Scale scores and fatherhood life course intervals.ResultsDepressive symptom scores reported at the entry into fatherhood are higher for nonresident fathers than nonfathers, which in turn are higher than those of resident fathers. Resident fathers have a significant decrease in scores during late adolescence (β = -0.035, P = .023), but a significant increase in scores during early fatherhood (β = 0.023, P = .041). From entrance into fatherhood to the end of early fatherhood (+5 years), the depressive symptoms score for resident fathers increases on average by 68%.ConclusionsIn our longitudinal, population-based study, resident fathers show increasing depressive symptom scores during children's key attachment years of 0-5. Identifying at-risk fathers based on social factors and designing effective interventions may ultimately improve health outcomes for the entire family

Linking Physical and Mental Health Summary Scores from the Veterans RAND 12-Item Health Survey (VR-12) to the PROMIS(®) Global Health Scale.

BackgroundGlobal health measures represent an attractive option for researchers and clinicians seeking a brief snapshot of a patient's overall perspective on his or her health. Because scores on different global health measures are not comparable, comparative effectiveness research (CER) is challenging.ObjectiveTo establish a common reporting metric so that the physical and mental health scores on the Veterans RAND 12-Item Health Survey (VR-12 (©) ) can be converted into scores on the corresponding Patient Reported Outcomes Measurement Information System (PROMIS(®)) Global Health scores.DesignFollowing a single-sample linking design, participants from an Internet panel completed items from the PROMIS Global Health and VR-12 Health Survey. A common metric was created using analyses based on item response theory (IRT), producing score cross-walk tables for the mental and physical health components of each measure. The linking relationships were evaluated by calculating the standard deviation of differences between the observed and linked PROMIS scores and estimating confidence intervals by sample size.ParticipantsParticipants (N = 2025) were 49 % male and 73 % white; mean age was 46 years.Main measuresMental and physical health subscales of the PROMIS Global Health and the VR-12. The mean VR-12 physical component and mental component scores were 45.2 and 46.6, respectively; the mean PROMIS physical and mental health scores were 48.3 and 48.5, respectively.Key resultsWe found evidence that the combined set of VR-12 and PROMIS items were relatively unidimensional and that we could proceed with linking. Linking worked better between the physical health than mental health scores using VR-12 item responses (vs. linking based on algorithmic scores). For each of the cross-walks, users can minimize the impact of linking error with modest increases in sample sizes.ConclusionsVR-12 scores can be expressed on the PROMIS Global Health metric to facilitate the evaluation of treatment, including CER. Extending these results to other common measures of global health is encouraged

Longitudinal Study of Body Mass Index in Young Males and the Transition to Fatherhood.

Despite a growing understanding that the social determinants of health have an impact on body mass index (BMI), the role of fatherhood on young men's BMI is understudied. This longitudinal study examines BMI in young men over time as they transition from adolescence into fatherhood in a nationally representative sample. Data from all four waves of the National Longitudinal Study of Adolescent Health supported a 20-year longitudinal analysis of 10,253 men beginning in 1994. A "fatherhood-year" data set was created and changes in BMI were examined based on fatherhood status (nonfather, nonresident father, resident father), fatherhood years, and covariates. Though age is positively associated with BMI over all years for all men, comparing nonresident and resident fathers with nonfathers reveals different trajectories based on fatherhood status. Entrance into fatherhood is associated with an increase in BMI trajectory for both nonresident and resident fathers, while nonfathers exhibit a decrease over the same period. In this longitudinal, population-based study, fatherhood and residence status play a role in men's BMI. Designing obesity prevention interventions for young men that begin in adolescence and carry through young adulthood should target the distinctive needs of these populations, potentially improving their health outcomes

Adolescent Reproductive Knowledge, Attitudes, and Beliefs and Future Fatherhood.

PurposeWith a growing focus on the importance of men's reproductive health, including preconception health, the ways in which young men's knowledge, attitudes, and beliefs (KAB) predict their reproductive paths are understudied. To determine if reproductive KAB predicts fatherhood status, timing and residency (living with child or not).MethodsReproductive KAB and fatherhood outcomes were analyzed from the National Longitudinal Study of Adolescent Health, a 20-year, nationally representative study of individuals from adolescence into adulthood. Four measures of reproductive KAB were assessed during adolescence in waves I and II. A generalized linear latent and mixed model predicted future fatherhood status (nonfather, resident/nonresident father, adolescent father) and timing while controlling for other socio-demographic variables.ResultsOf the 10,253 men, 3,425 were fathers (686 nonresident/2,739 resident) by wave IV. Higher risky sexual behavior scores significantly increased the odds of becoming nonresident father (odds ratio [OR], 1.30; p &lt; .0001), resident father (OR, 1.07; p&nbsp;= .007), and adolescent father (OR, 1.71; p &lt; .0001); higher pregnancy attitudes scores significantly increased the odds of becoming a nonresident father (OR, 1.20; p &lt; .0001) and resident father (OR, 1.11; p &lt; .0001); higher birth control self-efficacy scores significantly decreased the odds of becoming a nonresident father (OR, .72; p &lt; .0001) and adolescent father (OR, .56; p&nbsp;= .01).ConclusionsYoung men's KAB in adolescence predicts their future fatherhood and residency status. Strategies that address adolescent males' reproductive KAB are needed in the prevention of unintended reproductive consequences such as early and nonresident fatherhood