The Life Course Origins of the Race Disparity in Cognitive Functioning in Brazil

Background Cognitive health is a major concern for understanding population health in Brazil. Race inequalities have been found for several health outcomes but less is known about older adult cognitive health. Health inequalities have been tied to several life course factors, but less is known about how the racial stratification in Brazil may contribute to race disparities in cognitive health. Method: Data come from the Brazilian Longitudinal Study of Aging. We used nested regression models to examine the life course origins of the race differences in cognitive functioning. Results Whites had better cognitive functioning than non-Whites. Education reduced these differences by about half. Health behaviors and cardiometabolic conditions had little to no impact. Discussion Race differences in cognitive functioning in Brazil are in large part attributable to educational opportunities. These finding point to the importance of cognitive development in childhood to understand racial disparities in later life cognitive health.

Visual and oculomotor abilities predict professional baseball batting performance

Scientists and practitioners have long debated about the specific visual skills needed to excel at hitting a pitched baseball. This study aimed to advance the debate by evaluating the relationship between pre-season visual and oculomotor evaluations and pitch-by-pitch season performance data from professional baseball batters. Eye tracking, visual-motor, and optometric evaluations collected during spring training 2018 were obtained from 71 professional baseball players. Pitch-level data from Trackman 3D Doppler radar were obtained from these players during the subsequent season and used to generate batting propensity scores for swinging at pitches out of the strike zone (O-Swing), swinging at pitches in the strike zone (Z-Swing), and swinging at, but missing pitches in the strike zone (Z-Miss). Nested regression models were used to test which vision-related evaluation(s) could best predict the standardized plate discipline scores as well as the batters’ highest attained league levels during the season. Results indicated that visual evaluations relying on eye tracking (e.g., smooth pursuit accuracy and oculomotor processing speed) significantly predicted the highest attained league level and the propensity scores associated with O-Swing and Z-Swing, but not Z-Miss. These exploratory findings indicate that batters with superior visual and oculomotor abilities are generally more discerning at the plate. When combined with other known performance advantages in perceptual and cognitive abilities for elite athletes, these results provide a wholistic view of visual expertise in athletes.

Nested Nonlinear Regression Models

Stepwise fitting of nonlinear nested regression models is considered in this chapter. The forward stepwise method of linear model building is used as far as possible. With linear models this is straightforward as there is in principle a free choice of the order that individual terms or factors are selected for inclusion. The only real issue is that sufficient submodels are examined to ensure that those finally selected really are amongst the best. The nonlinear case is not so straightforward, as embeddedness and parameter indeterminacy issues impose restrictions on the order in which steps can be taken to build a valid model, as certain parameters can only be meaningfully included if other specific parameters are definitely present. A systematic way of building valid nonlinear models of increasing complexity is described and illustrated by two examples using real data. A brief review of non-nested model building is also given.

The MEssaging for Diabetes Intervention Reduced Barriers to Medication Adherence Among Low-Income, Diverse Adults With Type 2

Background: Nonadherence to diabetes medication is prevalent and costly. MEssaging for Diabetes (MED), a mobile health (mHealth) intervention, identified and addressed user-specific barriers to medication adherence. We assessed whether MED reduced users’ targeted barriers and if barrier reductions were associated with within-participant improvements in adherence or glycemic control (HbA1c). Methods: Adults (N = 80) with type 2 diabetes completed self-report measures identifying barriers to adherence at baseline and monthly for 3 months. At each assessment, 17 barriers were assessed and ranked for each user. Each subsequent month, users received daily text messages addressing their 3 highest ranked barriers. Targeted barriers were different for each participant and could change monthly. Paired t-tests assessed within-participant improvement in targeted barriers each month, and nested regression models assessed if changes in a participant’s barrier scores were associated with improvements in adherence and HbA1c. Results: Participants were 69% non-white and 82% had incomes <$25K. Average HbA1c was 8.2 ± 2.0%. Assessment completion rates were 100% at baseline, 59% at 1 month, 30% at 2 months, and 65% at 3 months. The most commonly reported barriers were the cost of medications (76%), believing medications are harmful (58%), and lacking information about medications (53%). Participants’ barrier scores improved each month and barrier improvement predicted adherence assessed via nightly adherence assessment text messages ( P < .001). Among participants who completed assessments each month, barrier improvement in months 2 and 3 ( P < .05) predicted HbA1c improvement. Conclusions: Iterative, individual tailoring may overcome users’ barriers to adherence. Attrition is a challenge for mHealth interventions among low-income patients.

Black and White or Shades of Grey? Comparing Social Representations Centrality Models

The present study, aligned with the structural approach on social representations (SR), aimed at comparing dichotomous (central vs. peripheral) and continuous models of structural status of SR elements. The sample was formed by 114 undergraduate students who completed context independence tasks and resistance to change evaluations related to 30 elements from 3 SR objects. Non-nested regression models having resistance to change as the criterion variable and dichotomous and continuous operationalizations of symbolic value as predictors were compared. Statistical results complemented by follow-up t-tests challenge the dichotomous model and support a continuous quadratic one. The curve is interpreted as being related to different evaluations when elements are attributed to a majority or a minority and point out to the need to employ within subjects designs in future research assessing more properties with composite measures.