Protocol of the study: Multilevel community-based mental health intervention to address structural inequities and adverse disparate consequences of COVID-19 pandemic on Latinx Immigrants and African refugees

The NIMH-funded Multilevel Community-Based Mental Health Intervention to Address Structural Inequities and Adverse Disparate Consequences of COVID-19 Pandemic on Latinx Immigrants and African Refugees study aims to advance the science of multilevel interventions to reduce the disparate, adverse mental health, behavioral, and socioeconomic consequences of the COVID-19 pandemic that are a result of complex interactions between underlying structural inequities and barriers to health care. The study tests three nested levels of intervention: 1) an efficacious 4-month advocacy and mutual learning model (Refugee and Immigrant Well-being Project, RIWP); 2) engagement with community-based organizations (CBOs); and 3) structural policy changes enacted in response to the pandemic. This community-based participatory research (CBPR) study builds on long-standing collaboration with five CBOs. By including 240 Latinx immigrants and 60 African refugees recruited from CBO partners who are randomly assigned to treatment-as-usual CBO involvement or the RIWP intervention and a comparison group comprised of a random sample of 300 Latinx immigrants, this mixed methods longitudinal waitlist control group design study with seven time points over 36 months tests the effectiveness of the RIWP intervention and engagement with CBOs to reduce psychological distress, daily stressors, and economic precarity and increase protective factors (social support, access to resources, English proficiency, cultural connectedness). The study also tests the ability of the RIWP intervention and engagement with CBOs to increase access to the direct benefits of structural interventions. This paper reports on the theoretical basis, design, qualitative and quantitative analysis plan, and power for the study.

Developing questions to assess and measure patients' perceived survival benefit from adjuvant endocrine therapy in breast cancer: a mixed methods pilot study

This mixed method study developed multiple question types to understand and measure women's perceived benefit from adjuvant endocrine therapy. We hypothesis that patients do not understand this benefit and sought to develop the questions needed to test this hypothesis and obtain initial patient estimates. From 8/2022 to 3/2023, qualitative interviews focused on assessing and modifying 9 initial varied question types asking about the overall survival (OS) benefit from adjuvant endocrine therapy. Subsequent focus groups modified and selected the optimal questions. Patients' self-assessment of their OS benefit was compared to their individualized PREDICT model results. Fifty-three patients completed the survey; 42% Hispanic, 30% rural, and 47% with income < $39,999 per year. Patients reported adequate health care literacy (61.5%) and average confidence about treatment and medication decisions 49.4 (95% CI 24.4-59.5). From the original 9 questions, 3 modified questions were ultimately found to capture patients' perception of this OS benefit, focusing on graphical and prose styles. Patients estimated an OS benefit of 42% compared to 4.4% calculated from the PREDICT model (p < 0.001). In this group with considerable representation from ethnic minority, rural and low-income patients, qualitative data showed that more than one modality of question type was needed to clearly capture patients' understanding of treatment benefit. Women with breast cancer significantly overestimated their 10-year OS benefit from adjuvant endocrine therapy compared to the PREDICT model.

Predictors of mental health outcomes of three refugee groups in an advocacy-based intervention: A precision medicine perspective

OBJECTIVE

Precision medicine is an area with great potential for mental health, but has made limited gains prognostically in predicting effective treatments. For refugees exposed to violence, culture may be a crucial factor in predicting treatment outcomes.

METHOD

For this study, 290 participants from three regions (Afghanistan, the Great Lakes region of Africa, and Iraq and Syria) participated in a randomized controlled trial of an advocacy-based intervention. Emotional distress symptoms were measured prior to intervention, midintervention (3 months), postintervention (6 months), and follow-up (6 months after the end of intervention). Number of traumatic events, resource access, social support, and English proficiency were tested for potential predictive effects on intervention outcome.

RESULTS

Multilevel generalized linear models revealed that Afghans' (B = -0.259, SE = 0.108, p = .013), and Great Lakes Africans' (B = -0.116, SE = 0.057, p = .042) emotional distress symptoms improved as a function of the intervention, while Iraqis and Syrians showed no intervention effects. For Afghans, English proficiency (B = -0.453, SE = 0.157, p < .01) and social support (B = -0.179, SE = 0.086, p = .037) were most strongly correlated to emotional distress, while for Africans, resource access (B = -0.483, SE = 0.082, p < .001) and social support (B = -0.100, SE = 0.048, p = .040) were the strongest predictors of emotional distress.

CONCLUSIONS

Response to advocacy-based interventions and active ingredients may be influenced by culture; findings have implications for refugees and precision medicine. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Novel Psychosocial Correlates of COVID-19 Vaccine Hesitancy: Cross-Sectional Survey

BACKGROUND

Effective COVID-19 vaccines have been available since early 2021 yet many Americans refuse or delayed uptake. As of mid-2022, still around 30% of US adults remain unvaccinated against COVID-19. The majority (81%) of these unvaccinated adults say they will "definitely not" be getting the COVID-19 vaccine. Understanding the determinants of COVID-19 vaccine uptake is critical to reducing death and illness from the virus, as well as to inform future vaccine efforts, such as the more recent bivalent (omicron) booster.

OBJECTIVE

This study aimed to expand our understanding of psychosocial determinants of COVID-19 vaccine uptake. We focus on both COVID-19-specific factors, such as COVID-19 conspiracy beliefs, as well as more global personality attributes such as dogmatism, reactance, gender roles, political beliefs, and religiosity.

METHODS

We conducted a web-based survey in mid-2021 of a representative sample of 1376 adults measuring both COVID-19-specific beliefs and attitudes, as well as global personality attributes. COVID-19 vaccination status is reported at 3 levels: vaccinated; unvaccinated-may-get-it; unvaccinated-hard-no.

RESULTS

Our analyses focused on the correlation of COVID-19 vaccination status with 10 psychosocial attributes: COVID-19-specific conspiracy theory beliefs; COVID-19 vaccine misinformation; COVID-19-related Rapture beliefs; general antivaccination beliefs; trait reactance; trait dogmatism; belief in 2020 election fraud; belief in a QAnon conspiracy; health care system distrust; and identification with traditional gender roles. We used a multivariate analysis of covariance to examine mean differences across vaccine status groups for each of the correlates while holding constant the effects of age, gender, race, income, education, political party, and Evangelicalism. Across the 10 psychosocial correlates, several different response scales were used. To allow for comparison of effects across correlates, measures of effect size were computed by converting correlates to z scores and then examining adjusted mean differences in z scores between the groups. We found that all 10 psychosocial variables were significantly associated with vaccination status. After general antivaccination beliefs, COVID-19 misinformation beliefs and COVID-19 conspiracy beliefs had the largest effect on vaccine uptake.

CONCLUSIONS

The association of these psychosocial factors with COVID-19 vaccine hesitancy may help explain why vaccine uptake has not shifted much among the unvaccinated-hard-no group since vaccines became available. These findings deepen our understanding of those who remain resistant to getting vaccinated and can guide more effective tailored communications to reach them. Health communication professionals may apply lessons learned from countering related beliefs and personality attributes around issues such as climate change and other forms of vaccine hesitancy. For example, using motivational interviewing strategies that are equipped to handle resistance and provide correct information in a delicate manner that avoids reactance.

Engagement With Tailored Physical Activity Content: Secondary Findings From the Families Improving Together for Weight Loss Randomized Controlled Trial

BACKGROUND

Web-based tailored interventions offer rich opportunities for improved access to and personalization of behavioral interventions. However, despite the promise of this approach, the engagement and underrepresentation of minority groups remain major issues.

OBJECTIVE

This study evaluated whether engagement (log-in status and log-in duration) with different types of tailored behavioral content from the Families Improving Together for weight loss web-based intervention was associated with changes in moderate to vigorous physical activity (MVPA) among African American families with overweight or obesity.

METHODS

Parent-adolescent dyads were randomized to a web-based tailored intervention or web-based health education comparison program. The web-based intervention (N=119) was completed by parents and targeted 6 weight-related behaviors to support their adolescent children's weight loss goals (session contents included energy balance, fast food, fruits and vegetables, physical activity [PA], sedentary behavior, and sweetened beverages). MVPA was measured using accelerometers at baseline and after the intervention.

RESULTS

Using a hierarchical approach, the log-in status and duration for each web-based session were used to evaluate the additive effects of engagement with different types of tailored behavioral content on MVPA after the web-based intervention. Among parents, logging in to the PA session was not associated with greater MVPA (B=-12.561, 95% CI -18.759 to -6.367), but MVPA increased with greater log-in duration for the PA (B=0.008, 95% CI 0.004-0.012) and sedentary behavior (B= 0.008, 95% CI 0.004-0.012) sessions. These results suggest that parents who logged in to the PA session had lower MVPA, but MVPA increased with greater log-in duration for the PA and sedentary behavior sessions. These associations remained even after accounting for engagement with other content sessions. However, these engagement effects did not translate to the adolescents.

CONCLUSIONS

The results of this study highlight the need to disentangle the impact of engagement with different tailored content to improve the efficacy of tailored web-based interventions, especially for promoting PA in African American families.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01796067; https://clinicaltrials.gov/ct2/show/NCT01796067.

An intensive longitudinal examination of topiramate treatment for alcohol use disorder: a secondary analysis of data from a randomized controlled trial

BACKGROUND AND AIMS

Previous findings have been equivocal as to whether a single-nucleotide polymorphism (rs2832407) in GRIK1, which encodes a glutamate receptor subunit, moderates the effects of topiramate treatment for drinking reduction. We leveraged intensive longitudinal data to provide greater precision and allow an examination of intermediate outcomes addressing this question. We used data from a randomized controlled trial (RCT) to test the hypotheses that topiramate treatment reduces daily heavy drinking, desire to drink and positive alcohol expectancies and that these effects are stronger in rs2832407*C-allele homozygotes.

DESIGN

Secondary data analysis of a randomized controlled trial.

SETTING

University of Pennsylvania Treatment Research Center in the United States.

PARTICIPANTS/CASES

Participants were 164 individuals (70.1% male, mean age = 51.42, 36.0% rs2832407*C-allele homozygotes) who sought to reduce or stop drinking.

INTERVENTION AND COMPARATOR

Participants were assigned to medication (topiramate or placebo), with stratification by genotype group (CC versus AA/AC) and treatment goal (reduce versus abstain).

MEASUREMENTS

During the 12-week treatment period, participants completed daily interactive voice response (IVR) surveys.

FINDINGS

On any given day during treatment, participants who received topiramate had lower odds of IVR-reported heavy drinking [odds ratio (OR) = 0.259, b (standard error, SE) = -1.351 (0.334), P < 0.001] and lower levels of desire to drink [b (SE) = -0.323 (0.122), P = 0.009] and positive alcohol expectancies [b (SE) = -0.347 (0.138), P = 0.013] than those who received placebo. Participants who received topiramate also reported greater reductions in positive alcohol expectancies during the first 2 weeks of treatment than those who received placebo [b (SE) = -0.028 (0.008), P = 0.001], but topiramate did not impact the daily rate of change in heavy drinking or desire to drink. Genotype did not moderate the effects of topiramate on any outcomes examined (P > 0.05).

CONCLUSIONS

Topiramate is an effective medication for individuals seeking to reduce heavy drinking. The effects are not moderated by the single-nucleotide polymorphism rs2832407.

Results from "Developing Real Incentives and Volition for Exercise" (DRIVE): A pilot randomized controlled trial for promoting physical activity in African American women

OBJECTIVE

Motivation is a barrier to physical activity (PA) among African American (AA) women, but past studies have implemented a "one-size-fits-all" approach and have not addressed differences in autonomous motivation. This pilot randomized controlled trial assessed the preliminary efficacy of "Developing Real Incentives and Volition for Exercise," a community- and theory-based intervention, which evaluated whether a motivationally matched (vs. a nonmatched) intervention increases daily total PA.

METHOD

In total, 68 AA women (50.72 ± 13.66 years; 86.8% with obesity) were randomized to an 8-week challenge-focused program (targeted toward high autonomous motivation) or rewards-focused program (targeted toward low autonomous motivation). Randomization was stratified by baseline autonomous motivation. FitBits were used during the intervention to promote self-monitoring (both programs) and social connectedness (challenge program only).

RESULTS

Both programs retained ≥ 80% of participants. Process evaluation revealed high attendance, dose, and fidelity (both programs). However, contrary to expectations, across all motivational levels (low and high autonomous), the challenge-focused intervention resulted in a greater increase in total daily PA (primary outcome), with an average increase of 17.9 min in the challenge-focused intervention versus an average decrease of 8.55 min in the rewards-focused intervention. An exploratory follow-up analysis revealed that engagement with the FitBit mobile app predicted greater PA at postintervention in the challenge-focused program.

CONCLUSIONS

A team-based approach targeting social connectedness, enjoyment of PA, and positive intragroup competition is a promising approach for promoting PA among AA women. These findings are used to guide a discussion on best practices for engaging AA women in future behavioral interventions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Individual differences in the effects of the ACTION-PAC intervention: an application of personalized medicine in the prevention and treatment of obesity

There is an increased interest in the use of personalized medicine approaches in the prevention or treatment of obesity, however, few studies have used these approaches to identify individual differences in treatment effects. The current study demonstrates the use of the predicted individual treatment effects framework to test for individual differences in the effects of the ACTION-PAC intervention, which targeted the treatment and prevention of obesity in a high school setting. We show how methods for personalized medicine can be used to test for significant individual differences in responses to an intervention and we discuss the potential and limitations of these methods. In our example, 25% of students in the preventive intervention, were predicted to have their BMI z-score reduced by 0.39 or greater, while at other end of the spectrum, 25% were predicted to have their BMI z-score increased by 0.09 or more. In this paper, we demonstrate and discuss the process of using methods for personalized medicine with interventions targeting adiposity and discuss the lessons learned from this application. Ultimately, these methods have the potential to be useful for clinicians and clients in choosing between treatment options, however they are limited in their ability to help researchers understand the mechanisms underlying these predictions.

Teacher's Corner: An R Shiny App for Sensitivity Analysis for Latent Growth Curve Mediation

Mechanisms of behavior change are the processes through which interventions are hypothesized to cause changes in outcomes. Latent growth curve mediation models (LGCMM) are recommended for investigating the mechanisms of behavior change because LGCMM models establish temporal precedence of change from the mediator to the outcome variable. The Correlated Augmented Mediation Sensitivity Analyses (CAMSA) App implements sensitivity analysis for LGCMM models to evaluate if a mediating path (mechanism) is robust to potential confounding variables. The CAMSA approach is described and applied to simulated data, and data from a research study exploring a mechanism of change in the treatment of substance use disorder.

The Results of the Families Improving Together (FIT) for Weight Loss Randomized Trial in Overweight African American Adolescents

BACKGROUND

Few intervention studies have integrated cultural tailoring, parenting, behavioral, and motivational strategies to address African American adolescent weight loss.

PURPOSE

The Families Improving Together (FIT) for Weight Loss trial was a randomized group cohort study testing the efficacy of a cultural tailoring, positive parenting, and motivational intervention for weight loss in overweight African American adolescents (N = 241 adolescent/caregiver dyads).

METHODS

The trial tested an 8-week face-to-face group motivational plus family weight loss program (M + FWL) compared with a comprehensive health education control program. Participants were then rerandomized to an 8-week tailored or control online program to test the added effects of the online intervention on reducing body mass index and improving physical activity (moderate-to-vigorous physical activity [MVPA], light physical activity [LPA]), and diet.

RESULTS

There were no significant intervention effects for body mass index or diet. There was a significant effect of the group M + FWL intervention on parent LPA at 16 weeks (B = 33.017, SE = 13.115, p = .012). Parents in the group M + FWL intervention showed an increase in LPA, whereas parents in the comprehensive health education group showed a decrease in LPA. Secondary analyses using complier average causal effects showed a significant intervention effect at 16 weeks for parents on MVPA and a similar trend for adolescents.

CONCLUSIONS

While the intervention showed some impact on physical activity, additional strategies are needed to impact weight loss among overweight African American adolescents.

A permutation test for assessing the presence of individual differences in treatment effects

An important goal of personalized medicine is to identify heterogeneity in treatment effects and then use that heterogeneity to target the intervention to those most likely to benefit. Heterogeneity is assessed using the predicted individual treatment effects framework, and a permutation test is proposed to establish if significant heterogeneity is present given the covariates and predictive model or algorithm used for predicted individual treatment effects. We first show evidence for heterogeneity in the effects of treatment across an illustrative example data set. We then use simulations with two different predictive methods (linear regression model and Random Forests) to show that the permutation test has adequate type-I error control. Next, we use an example dataset as the basis for simulations to demonstrate the ability of the permutation test to find heterogeneity in treatment effects for a predicted individual treatment effects estimate as a function of both effect size and sample size. We find that the proposed test has good power for detecting heterogeneity in treatment effects when the heterogeneity was due primarily to a single predictor, or when it was spread across the predictors. Power was found to be greater for predictions from a linear model than from random forests. This non-parametric permutation test can be used to test for significant differences across individuals in predicted individual treatment effects obtained with a given set of covariates using any predictive method with no additional assumptions.

Interaction of Neighborhood and Genetic Risk on Waist Circumference in African-American Adults: A Longitudinal Study

BACKGROUND

Understanding determinants of metabolic risk has become a national priority given the increasingly high prevalence rate of this condition among U.S. adults.

PURPOSE

This study's aim was to assess the impact of gene-by-neighborhood social environment interactions on waist circumference (WC) as a primary marker of metabolic risk in underserved African-American adults. Based on a dual-risk model, it was hypothesized that those with the highest genetic risk and who experienced negative neighborhood environment conditions would demonstrate higher WC than those with fewer risk factors.

METHODS

This study utilized a subsample of participants from the Positive Action for Today's Health environmental intervention to improve access and safety for walking in higher-crime neighborhoods, who were willing to provide buccal swab samples for genotyping stress-related genetic pathways. Assessments were conducted with 228 African-American adults at baseline, 12, 18, and 24 months.

RESULTS

Analyses indicated three significant gene-by-environment interactions on WC outcomes within the sympathetic nervous system (SNS) genetic pathway. Two interactions supported the dual-risk hypotheses, including the SNS genetic risk-by-neighborhood social life interaction (b = -0.11, t(618) = -2.02, p = .04), and SNS genetic risk-by-informal social control interaction (b = -0.51, t(618) = -1.95, p = .05) on WC outcomes. These interactions indicated that higher genetic risk and lower social-environmental supports were associated with higher WC. There was also one significant SNS genetic risk-by-neighborhood satisfaction interaction (b = 1.48, t(618) = 2.23, p = .02) on WC that was inconsistent with the dual-risk pattern.

CONCLUSIONS

Findings indicate that neighborhood and genetic factors dually influence metabolic risk and that these relations may be complex and warrant further study.

TRIAL REGISTRATION

NCT01025726.

Latent Class Mediation: A Comparison of Six Approaches

Latent class mediation modeling is designed to estimate the mediation effect when both the mediator and the outcome are latent class variables. We suggest using an adjusted one-step approach in which the latent class models for the mediator and the outcome are estimated first to decide on the number of classes, then the latent class models and the mediation model are jointly estimated. We present both an empirical demonstration and a simulation study to compare the performance of this one-step approach to a standard three-step approach with modal assignment (modal) and four different modern three-step approaches. Results from the study indicate that unadjusted modal, which ignores the classification errors of the latent class models, produced biased mediation effects. On the other hand, the adjusted one-step approach and the modern three-step approaches performed well with respect to bias for estimating mediation effects, regardless of measurement quality (i.e., model entropy) and latent class size. Among the three-step approaches we investigated, the maximum likelihood method with modal assignment and the BCH correction with robust standard error estimators are good alternatives to the adjusted one-step approach, given their unbiased standard error estimations.

Development of a coronavirus social distance attitudes scale

OBJECTIVE

Our goal was to develop a scale to assess social distance attitudes related to COVID-19.

METHODS

We performed an online national survey of US adults (n = 1,074) to assess social distance attitudes, COVID-19 related beliefs and behaviors, and demographics. We assessed scale structure using confirmatory factor analysis and evaluated internal consistency and validity. We assessed association of scale factors with respondent characteristics.

RESULTS

Confirmatory factor analysis supported a hypothesized two-factor solution. Internal consistency was high for both positive (Alpha = 0.92) and negative (Alpha = 0.91) attitude factors. Analyses supported construct and predictive validity with expected associations between scale factors and perceived norms and behavior (e.g. trips out of the home). We found an interaction suggesting that holding highly negative attitudes reduced the effect of holding positive beliefs. Both attitude factors were related to age, gender, race/ethnicity, and political affiliation. Perceived COVID-19 risk (to others but not for self) and perceived severity were consistently associated with higher positive and lower negative attitudes.

CONCLUSION

This COVID-19 Social Distance Attitude Scale contains positive and negative factors with high internal consistency and construct and predictive validity.

PRACTICE IMPLICATION

A greater understanding and ongoing assessment of COVID-19 social distance attitudes could inform policymakers, researchers, and clinicians who seek to promote protective social distance behaviors.

Novel Predictors of COVID-19 Protective Behaviors Among US Adults: Cross-sectional Survey

Background

A central component of the public health strategy to control the COVID-19 pandemic involves encouraging mask wearing and social distancing to protect individuals from acquiring and transmitting the virus.

Objective

This study aims to understand the psychological factors that drive adoption or rejection of these protective behaviors, which can inform public health interventions to control the pandemic.

Methods

We conducted an online survey of a representative sample of 1074 US adults and assessed three novel potential predictors of COVID-19 behaviors: trait reactance, COVID-19 conspiracy beliefs, and COVID-19 apocalypse beliefs. Key outcomes (dependent variables) included an index of COVID-19 protective behaviors, the number of trips taken from the home, and COVID-19 knowledge.

Results

In bivariate analyses, all three predictors were significantly correlated in the hypothesized direction with the three COVID-19 outcomes. Specifically, each predictor was negatively (P<.01) correlated with the COVID-19 protective behaviors index and COVID-19 knowledge score, and positively correlated with trips taken from home per week (more of which was considered higher risk). COVID-19 protective behaviors and COVID-19 knowledge were significantly lower in the top median compared to the bottom median for all three predictors. In general, these findings remained significant after adjusting for all novel predictors plus age, gender, income, education, race, political party, and religiosity. Self-identified Republicans (vs other political affiliations) reported the highest values for each of the novel predictors.

Conclusions

This study can inform the development of health communication interventions to encourage the adoption of COVID-19 protective behaviors. Interestingly, we found that higher scores of all three novel predictors were associated with lower COVID-19 knowledge, suggesting that lack of an accurate understanding of the virus may be driving some of these attitudes; although, it is also possible that these attributes may interfere with one’s willingness or ability to seek and absorb accurate health information. These individuals may be particularly immune to accepting new information and yielding their beliefs. Health communication professionals may apply lessons learned from countering similar beliefs around climate change and vaccine hesitancy. Messages designed for individuals prone to reactance may be more effective if they minimize controlling language and emphasize the individual’s independence in adopting these behavioral recommendations. Messaging for those who possess conspiracy beliefs should similarly not assume that providing evidence contrary to these beliefs will alone alter behavior. Other communication techniques such as rolling with resistance, a strategy used in motivational interviewing, may be helpful. Messaging for those with apocalyptic beliefs may require using religious leaders as the message source and using scripture that would support the adoption of COVID-19 protection behaviors.

Applying methods for personalized medicine to the treatment of alcohol use disorder

OBJECTIVE

Numerous behavioral treatments for alcohol use disorder (AUD) are effective, but there are substantial individual differences in treatment response. This study examines the potential use of new methods for personalized medicine to test for individual differences in the effects of cognitive behavioral therapy (CBT) versus motivational enhancement therapy (MET) and to provide predictions of which will work best for individuals with AUD. We highlight both the potential contribution and the limitations of these methods.

METHOD

We performed secondary analyses of abstinence among 1,144 participants with AUD participating in either outpatient or aftercare treatment who were randomized to receive either CBT or MET in Project MATCH. We first obtained predicted individual treatment effects (PITEs), as a function of 19 baseline client characteristics identified a priori by MATCH investigators. Then, we tested for the significance of individual differences and examined the predicted individual differences in abstinence 1 year following treatment. Predictive intervals were estimated for each individual to determine if they were 80% more likely to achieve abstinence in one treatment versus the other.

RESULTS

Results indicated that individual differences in the likelihood of abstinence at 1 year following treatment were significant for those in the outpatient sample, but not for those in the aftercare sample. Individual predictive intervals showed that 37% had a better chance of abstinence with CBT than MET, and 16% had a better chance of abstinence with MET. Obtaining predictions for a new individual is demonstrated.

CONCLUSIONS

Personalized medicine methods, and PITE in particular, have the potential to identify individuals most likely to benefit from one versus another intervention. New personalized medicine methods play an important role in putting together differential effects due to previously identified variables into one prediction designed to be useful to clinicians and clients choosing between treatment options. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The role of parental support for youth physical activity transportation and community-level poverty in the healthy communities study

This study evaluates whether parental provision of transportation for physical activity is associated with child/adolescent moderate-to-vigorous physical activity, while also evaluating community-level poverty. Self- and parental-reported surveys were administered with parents/caregivers and children in the Healthy Communities Study (N = 5138). Associations between individual-level demographics, community-level poverty, parental provision of transportation for physical activity, and moderate-to-vigorous physical activity were examined in multi-level models. Even when accounting for community-level poverty, which was significantly associated with lower moderate-to-vigorous physical activity, parental provision of transportation for physical activity was positively associated with greater moderate-to-vigorous physical activity. This study provides evidence for the importance of considering multiple systems of influence (e.g., community and individual factors) and considering how gaps in physical activity transportation for youth can be addressed in future health policies.

Effects of Parenting and Perceived Stress on BMI in African American Adolescents

OBJECTIVE

This study set out to examine the role of parenting practices in protecting or exacerbating the negative effects of parent and adolescent stress on adolescent body mass index (BMI) over time. Separate longitudinal models were conducted to evaluate how parenting practices interacted with parental perceived stress and adolescent perceived stress in predicting adolescent BMI.

METHODS

Baseline data were collected from 148 African American adolescents (Mage = 12.93, SD = 1.75; Mz-BMI = 0.78, SD = 0.50; MBMI%-ile = 96.7, SD = 3.90) and their caregivers (Mage = 44.45, SD = 8.65; MBMI = 37.63, SD = 8.21) enrolled in the Families Improving Together for Weight Loss trial. Adolescents self-reported their perceptions of caregiver parenting style and feeding practices. Both caregivers and adolescents self-reported their perceptions of chronic stress. BMI for parents and adolescents was assessed objectively at baseline and 16 weeks post-intervention.

RESULTS

Hierarchical regression models predicting adolescent BMI z-score (z-BMI) indicated a significant interaction between parental perceived stress and parental pressure to eat. Simple slopes analyses demonstrated that for those parents that exhibit higher pressure to eat, parent stress was positively associated with adolescent z-BMI.

CONCLUSIONS

These findings provide preliminary support suggesting that certain parenting practices interact with chronic stress on adolescent weight-related outcomes and that future interventions may consider integrating these factors.

Development of an Ethnic Identity Measure for Americans of Middle Eastern and North African Descent: Initial Psychometric Properties, Sociodemographic, and Health Correlates

Background

Southeast Michigan is home to the second largest Middle Eastern and North African (MENA) US population. There is increasing interest in understanding correlates of psychosocial outcomes and health behaviors in this growing population. One potentially important health correlate is ethnic identity (EI). This paper reports the development, validity, and initial correlates of a new measure of MENA identity named the MENA-IM.

Methods

We used convenience sampling at locations frequented by individuals of MENA descent in southeast Michigan. We also measured EI centrality, religiosity, cultural mistrust, substance use, and health status to assess convergent and divergent validity. Exloratory and Confirmatory Factor Analysis identified three subscales, which were valid for both Arab and Chaldean respondents and were named (1) MENA cultural affiliation, (2) MENA media use, and (3) multicultural affiliation. We also created and tested a 20-item, single-factor version.

Results

We obtained data from 378 adults, 73% of whom identified as Arab and 27% as Chaldean. MENA-IM scores were higher among older, lower-educated, lower-income, non-US born, and Arabic-speaking respondents. Arab respondents reported significantly higher scores than Chaldeans. MENA-IM scores were positively associated with EI centrality and religiosity. Higher MENA-IM scores were found among those not reporting use of marijuana, alcohol, and opiates. Higher MENA-IM scores were also found among those without a self-reported history of heart disease and among those with better mental health status.

Discussion

The MENA-IM has strong psychometric properties and demonstrated initial evidence of convergent and discriminant validity. In general, values on the measure were associated with better psychosocial and health status. How the measure performs with MENA populations outside of Michigan and how it may relate to other health outcomes merit investigation.

The Moderating Effects of Social Support and Stress on Physical Activity in African American Women

BACKGROUND

African American women participate in less physical activity (PA), have higher rates of chronic disease, and report higher perceived stress relative to other race and sex demographic groups.

PURPOSE

Based on the stress-buffering hypothesis, this study tested the hypothesis that social support would buffer the negative effects of perceived stress on moderate-to-vigorous PA (MVPA) under high, but not low, perceived stress.

METHODS

Participants were 143 African American women (mean [M] age = 43.94, standard deviation [SD] = 8.62; M body mass index = 37.94, SD = 8.11) enrolled in the Families Improving Together (FIT) for Weight Loss Trial. Average daily minutes of MVPA were obtained via 7 day accelerometer estimates at baseline and 8 and 16 weeks.

RESULTS

A multilevel growth model demonstrated a significant three-way interaction between stress, social support, and time (B = -0.31, standard error [SE] = 0.14, p = .03). Simple slopes analyses revealed that, at baseline, among participants with high social support (+1 SD), stress was positively associated with greater MVPA (B = 0.49, SE = 0.18, p = .008), whereas among participants with low social support (-1 SD), stress was not significantly associated with MVPA (B = -0.04, SE = 0.14, p = .81). However, at 8 and 16 weeks, stress was not significantly associated with MVPA for either high or low support groups.

CONCLUSIONS

Findings highlight the importance of integrating constructs of stress and social support into future physical activity intervention programs for African American women and the need to evaluate changes in stress and social support longitudinally.

The Feasibility and Acceptability of the Developing Real Incentives and Volition for Exercise (DRIVE) Program: A Pilot Study for Promoting Physical Activity in African American Women

Background. The purpose of the current article is to demonstrate how formative process evaluation was used in a pilot study to optimize the design and implementation of two motivationally targeted community-based physical activity (PA) interventions for inactive African American women. Method. Fifteen African American women (M age: 41.6 years) were randomized to a challenge-focused program targeted toward high autonomous motivation or a rewards-focused program targeted toward low autonomous motivation. The challenge-focused program targeted enjoyment and valuation of PA and a team-based positive social climate through competitive intergroup activities and team-based goals, whereas the rewards-focused program targeted PA interest, competency, and partner-based social support through a walking program, individual-based goals with financial incentives, and partner-based action-plans. Results. Feedback from participants revealed high levels of acceptability of essential elements. Average weekly attendance exceeded the a priori goal of ≥75% of members in attendance each week. External systematic observation demonstrated that session content dose was ≥93% in both programs. Facilitator-level fidelity exceeded the a priori goal of averaging ≥3 on a 4-point scale for behavioral skills, communication, autonomy support, and session content. The process evaluation also revealed areas for improvement, including facilitator-level social support and behavioral skills at the group-level. Process data collected through FitBits revealed that participants were engaged in self-monitoring PA during the 6-week programs. Conclusions. The formative process evaluation demonstrated adequate levels of feasibility and acceptability and also provided key insights into adjustments needed before proceeding with implementing the motivationally targeted group-based programs in a larger randomized study.

Daily physical activity and alcohol use among young adults

Evidence suggests that physical activity and alcohol use are positively related among young adults. Two studies have examined daily relations, and results have shown conflicting findings. We examined relations between physical activity and alcohol use at both within- and between-individual levels and investigated moderators of the relation at both levels. 269 college students wore accelerometers to collect physical activity data over a 2-week period. At the end of each day, they indicated whether or not they drank alcohol. Multilevel logistic regression indicated neither within- nor between-subject relations were statistically significant. Positive affect, negative affect, and drinking motives moderated these relations at the between-subject level. Contrary to previous research, we did not observe a relation between physical activity and alcohol use at the daily level. Unique features of the current study suggest next steps for future research examining the perplexing PA-alcohol relation in this population.

Broad Coping Repertoire Mediates the Effect of the Combined Behavioral Intervention on Alcohol Outcomes in the COMBINE Study: An Application of Latent Class Mediation

OBJECTIVE

Few studies have found support for coping as a mechanism of behavior change (MOBC) following coping skills training interventions for alcohol use disorder (AUD). One potential reason for null findings is heterogeneity in the patterns of coping skills acquired during treatment. This study sought to identify latent classes of coping and to test the latent class variable as a mediator of the effect of a combined behavioral intervention for AUD.

METHOD

Secondary analyses of data from the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) Study (N = 1,124; mean age = 44.4 years; 69.1% male; 23.2% non-White), a multisite study of medication and behavioral treatments for individuals with AUD. Latent class mediation models were estimated to test whether patterns of alcohol-specific coping mediated the effect of combined behavioral intervention with medication management, as compared with medication management only, on drinking outcomes 12 months following treatment.

RESULTS

Three classes were identified, which differed in repertoire broadness, or the degree in which a wide range of different skills were used. Coping repertoire class was a significant mediator of the effect of the combined behavioral intervention on drinking outcomes. Receiving the combined behavioral intervention, in addition to medication management, predicted a greater likelihood of expected classification in the broad coping repertoire class, which in turn was associated with significant improvements in drinking outcomes.

CONCLUSIONS

Using the novel methodological approach of latent class mediation, this study identified coping repertoire as a significant mediator of behavioral intervention efficacy for AUD. Future work examining heterogeneity in mediators and outcomes may help refine AUD treatment to be maximally effective.

The Effects of Sample Size on the Estimation of Regression Mixture Models

Regression mixture models are a statistical approach used for estimating heterogeneity in effects. This study investigates the impact of sample size on regression mixture's ability to produce "stable" results. Monte Carlo simulations and analysis of resamples from an application data set were used to illustrate the types of problems that may occur with small samples in real data sets. The results suggest that (a) when class separation is low, very large sample sizes may be needed to obtain stable results; (b) it may often be necessary to consider a preponderance of evidence in latent class enumeration; (c) regression mixtures with ordinal outcomes result in even more instability; and (d) with small samples, it is possible to obtain spurious results without any clear indication of there being a problem.

The (Lack of) Replication of Self-Reported Mindfulness as a Mechanism of Change in Mindfulness-Based Relapse Prevention for Substance Use Disorders

The development and evaluation of mindfulness-based interventions for a variety of psychological and medical disorders has grown exponentially over the past 20 years. Yet, calls for increasing the rigor of mindfulness research and recognition of the difficulties of conducting research on the topic of mindfulness have also increased. One of the major difficulties is the measurement of mindfulness, with varying definitions across studies and ambiguity with respect to the meaning of mindfulness. There is also concern about the reproducibility of findings given few attempts at replication. The current secondary analysis addressed the issue of reproducibility and robustness of the construct of self-reported mindfulness across two separate randomized clinical trials of mindfulness-based relapse prevention (MBRP), as an aftercare treatment for substance use disorder. Specifically, we tested the robustness of our previously published findings, which identified a latent construct of mindfulness as a significant mediator of the effect of MBRP on reducing craving following treatment. First, we attempted to replicate the findings in a separate randomized clinical trial of MBRP. Second, we conducted sensitivity analyses to test the assumption of the no-omitted confounder bias in a mediation model. The effect of MBRP on self-reported mindfulness and overall mediation effect failed to replicate in a new sample. The effect of self-reported mindfulness in predicting craving following treatment did replicate and was robust to the no-omitted confounder bias. The results of this work shine a light on the difficulties in the measurement of mindfulness and the importance of examining the robustness of findings.

Language Skills, Behaviour Problems, and Classroom Emotional Support among Preschool Children from Low-income Families

The purpose of this study was to examine the relationship between language skills and behavioural problems and the potential moderating role of the quality of classroom emotional support in this relationship among 242 preschool children from low-income families. The Preschool Language Scale-5 was administered individually to each child. The quality of classroom emotional support was measured using the Emotional Support domain of the Classroom Assessment Scoring System for Pre-Kindergarten. Teachers and parents completed the Child Behaviour Checklist for Ages 1½-5. Results indicated the inverse relationship between language skills and behaviour problems varied by the level of classroom emotional support provided by teachers. Specifically, children with lower language skills exhibited higher levels of behaviour problems in classrooms where teachers provided lower levels of emotional support. Findings from this study have important implications for enhancing teachers' emotional support aimed at children with lower language skills and for future research.

Rural-Urban Differences in Baseline Dietary Intake and Physical Activity Levels of Adolescents

INTRODUCTION

Differences in dietary intake and physical activity may explain the higher prevalence of obesity among adolescents living in rural versus urban settings. The objective of this cross-sectional secondary analysis was to compare baseline dietary intake and physical activity of adolescents by rurality.

METHODS

We analyzed data on 940 adolescents who participated in ACTION PAC (Adolescents Committed to Improvement of Nutrition and Physical Activity), an obesity prevention and management intervention trial conducted from 2014 through 2017 in 8 public high schools in the southwestern United States. Dietary intake was assessed with the Block Food Screener, and participants completed an exercise log and wore an accelerometer to provide data on physical activity. We compared data by rural-urban commuting area (RUCA) codes and log population density by using multilevel models, with students nested within zip code and repeated measures for accelerometer analysis.

RESULTS

After adjusting for socioeconomic status and ethnicity, accelerometer data indicated that moderate-to-vigorous physical activity was 8.17 min/d (P = .02) higher and sedentary time was 20.42 min/d (P = .02) lower in moderately urban areas than in the urban reference area. Each 1-unit increase in log population density was associated with higher reported intake of whole grains (0.02 ounce equivalents, P = .03), potatoes (0.01 cup equivalents, P = .02), and added sugar (0.37 tsp, P = .02) after adjusting for socioeconomic status and ethnicity.

CONCLUSION

Differences in reported dietary intake and physical activity level by measures of rurality were small and inconsistent in direction to explain the disparities observed in rural versus urban areas.

Sensitivity Analysis of the No-Omitted Confounder Assumption in Latent Growth Curve Mediation Models

Latent growth curve mediation models are increasingly used to assess mechanisms of behavior change. For latent growth mediation model, like any another mediation model, even with random treatment assignment, a critical but untestable assumption for valid and unbiased estimates of the indirect effects is that there should be no omitted variable that confounds indirect effects. One way to address this untestable assumption is to conduct sensitivity analysis to assess whether the inference about an indirect effect would change under varying degrees of confounding bias. We developed a sensitivity analysis technique for a latent growth curve mediation model. We compute the biasing effect of confounding on point and confidence interval estimates of the indirect effects in a structural equation modeling framework. We illustrate sensitivity plots to visualize the effects of confounding on each indirect effect and present an empirical example to illustrate the application of the sensitivity analysis.

Does the structure of working memory in EL children vary across age and two language systems?

This study examined the cross-sectional structure of working memory (WM) among elementary school English learners (ELs). A battery of WM tasks was administered in Spanish (L1) and English (L2) within five age groups (ages 6, 7, 8, 9, & 10). Confirmatory factor analysis showed a three-factor structure of WM emerged in both L1 and L2 administrations for each age group. The important findings, however, were: (1) the separation between the executive component and storage component (phonological loop) structure of WM increased as a function of age within both language systems, (2) the structure of WM supported a domain general phonological storage component and a domain general executive system across both language systems, and (3) the visual-spatial WM system shared minimal variance with the executive system. Taken together, the findings support Baddeley's multicomponent model (e.g., Baddeley & Logie, 1999. The multiple-component model. In A. Miyake & P. Shah (Eds.), Models of working memory: Mechanisms of active maintenance and executive control (pp. 28-61). Cambridge: Cambridge University Press) as a good fit to the structure of WM in EL children's English and Spanish language system.

A DIAGNOSTIC TOOL FOR CHECKING ASSUMPTIONS OF REGRESSION MIXTURE MODELS

Regression mixture models are becoming more widely used in applied research. It has been recognized that these models are quite sensitive to underlying assumptions, yet many of these assumptions are not directly testable. We discuss a diagnostic tool based on reconstructed residuals that can help uncover violations of model assumptions. These residuals are found by using the posterior probability of class membership to assign, based on a multinomial distribution, a class to each observation. Standard residual checks can be applied to these posterior draw residuals to explore violations of the model assumptions. We present several illustrations of the diagnostic tool.

Associations Between Parenting Factors, Motivation, and Physical Activity in Overweight African American Adolescents

Background

Positive parenting practices and environmental supports have been linked to physical activity (PA) levels in youth, yet factors associated with positive parenting styles have been understudied in African American adolescents.

Purpose

This study expands on previous literature by examining associations between motivation, parenting factors associated with Self-Determination Theory's psychological needs (competence, autonomy, and relatedness) including authoritative parenting, autonomy support and emotional and tangible support, and adolescent moderate-to-vigorous PA (MVPA) and light PA (LPA).

Methods

Participants were African American adolescents (N = 148; Mage = 13.6 years; MBMI% = 96.6) and their care-givers (Mage = 43.4 years; MBMI = 37.4) enrolled in the Families Improving Together for Weight Loss trial. Parenting factors were measured using self-report surveys, and PA minutes were measured using 7-day accelerometry estimates.

Results

Regression analyses indicated that overall models for MVPA (F(11,134) = 4.35; R2 = 0.26) and LPA (F(11,134) = 5.84, R2 = 0.32) were significant. Adolescent motivation for PA (B = 0.58, SE = 0.16) was positively associated with MVPA minutes. Authoritative parenting (B = 15.71, SE = 4.38) and tangible support (B = 8.53, SE = 4.02) were positively associated with adolescent LPA minutes. Unexpectedly, emotional support was negatively associated with both MVPA (B = -0.47, SE = 0.17) and LPA (B = -11.22, SE = 4.79), with follow-up analyses showing this relationship stronger in males.

Conclusion

Findings highlight the importance of adolescent motivation for PA onMVPA and positive parenting styles and tangible supports on adolescent LPA in overweight African American youth. Recommendations for integrating these factors within the context of intervention studies are discussed.

An evaluation of the bootstrap for model validation in mixture models

Bootstrapping has been used as a diagnostic tool for validating model results for a wide array of statistical models. Here we evaluate the use of the non-parametric bootstrap for model validation in mixture models. We show that the bootstrap is problematic for validating the results of class enumeration and demonstrating the stability of parameter estimates in both finite mixture and regression mixture models. In only 44% of simulations did bootstrapping detect the correct number of classes in at least 90% of the bootstrap samples for a finite mixture model without any model violations. For regression mixture models and cases with violated model assumptions, the performance was even worse. Consequently, we cannot recommend the non-parametric bootstrap for validating mixture models. The cause of the problem is that when resampling is used influential individual observations have a high likelihood of being sampled many times. The presence of multiple replications of even moderately extreme observations is shown to lead to additional latent classes being extracted. To verify that these replications cause the problems we show that leave-k-out cross-validation where sub-samples taken without replacement does not suffer from the same problem.

Longitudinal relationships between self-concept for physical activity and neighborhood social life as predictors of physical activity among older African American adults

Background

Engaging in regular physical activity (PA) as an older adult has been associated with numerous physical and mental health benefits. The aim of this study is to directly compare how individual-level cognitive factors (self-efficacy for PA, self-determined motivation for PA, self-concept for PA) and neighborhood perceptions of the social factors (neighborhood satisfaction, neighborhood social life) impact moderate-to-vigorous physical activity (MVPA) longitudinally among older African American adults.

Methods

Data were analyzed from a sub-set of older African American adults (N = 224, M_age = 63.23 years, SD = 8.74, 63.23% female, M_{Body Mass Index} = 32.01, SD = 7.52) enrolled in the Positive Action for Today’s Health trial. MVPA was assessed using 7-day accelerometry-estimates and psychosocial data (self-efficacy for PA, self-determined motivation for PA, self-concept for PA, neighborhood satisfaction, neighborhood social life) were collected at baseline, 12-, 18-, and 24-months.

Results

Multilevel growth modeling was used to examine within- and between-person effects of individual-level cognitive and social environmental factors on MVPA. At the between-person level, self-concept (b = 0.872, SE = 0.239, p < 0.001), and neighborhood social life (b = 0.826, SE = 0.176, p < 0.001) predicted greater MVPA, whereas neighborhood satisfaction predicted lower MVPA (b = −0.422, SE = 0.172, p = 0.015). Among the between-person effects, only average social life was moderated by time (b = 0.361, SE = 0.147, p = 0.014), indicating that the impact of a relatively positive social life on MVPA increased across time. At the within-person level, positive increases in self-concept (b = 0.294, SE = 0.145, p = 0.043) and neighborhood social life (b = 0.270, SE = 0.113, p = 0.017) were associated with increased MVPA.

Conclusions

These results suggest that people with a higher average self-concept for PA and a more positive social life engaged in greater average MVPA. Additionally, changes in perceptions of one’s neighborhood social life and one’s self-concept for PA were associated with greater MVPA over 2 years. These factors may be particularly relevant for future interventions targeting long-term change and maintenance of MVPA in older African Americans.

Trial registration

ClinicalTrials.Gov #NCT01025726 registered 1 December 2009.

Family Resource Scale-Revised: Psychometrics and Validation of a Measure of Family Resources in a Sample of Low-Income Families

In studying child and family outcomes it is often critical to assess families' general availability of resources. Traditionally, many researchers have used income and SES to assess family resources. This study examined an alternative measure in a national sample of low-income families. Hypothesizing that Dunst and Leet's (1987) Family Resource Scale (FRS) assesses specific aspects of perceived family resources, exploratory and confirmatory factor analyses were conducted. Analyses supported a four-factor structure: Basic Needs, Money, Time for Self, and Time for Family. External validity was assessed by examining the relationship of subscale scores to other measures of family resources. Predictive validity was examined by evaluating the relationship with child cognitive and social outcomes. Subscales were found to fit the data consistently, to be moderately related to other measures of family resources, and to predict a meaningful amount of variance in child outcomes above and beyond family income, parent education, and parent work status.

Reliability of 24-Hour Dietary Recalls as a Measure of Diet in African-American Youth

BACKGROUND

Although it is a common practice to estimate dietary intake using three random 24-hour dietary recalls, some studies have suggested up to nine may be necessary to reliably estimate usual intake in youth. Given the resulting increase in resources and participant burden, more research is needed to determine whether this method is reliable, particularly in African-American youth at increased risk for obesity and other chronic diseases.

OBJECTIVE

This study estimated the reliability with which 24-hour dietary recalls measure energy, fat, fruit, and vegetable intake in African-American youth and examined how reliability changes as a function of the number of recalls.

DESIGN

This study used cross-sectional data collection across three studies.

PARTICIPANTS/SETTING

Participants were African-American youth (n=456, mean±standard deviation age 13.28±1.86 years, 64% were girls, mean±standard deviation body mass index [calculated as kg/m(2)] 31.45±7.94) who completed random 24-hour dietary recalls (67% completed three) conducted by research assistants using the Automated Self-Administered 24-Hour recall system (n=258) or registered dietitian nutritionists using the Nutrition Data System for Research (n=198).

MAIN OUTCOME MEASURES/STATISTICAL ANALYSES

Estimates provided by multilevel models were used to calculate the proportion of variance accounted for between individuals and the reliability of means within individuals as a function of the number of recalls.

RESULTS

Reliability estimates for assessing dietary outcomes using one to three recalls ranged from 11% to 62%. To achieve 80% reliability, the following number of recalls would need to be conducted: 8 for energy intake, 13 for fat intake, 21 to 32 for fruit intake, and 21 to 25 for vegetable intake.

CONCLUSIONS

The common practice of assessing dietary intake with three recalls does so with low reliability in African-American youth. Until more objective methods for reliably estimating usual intake are developed, researchers who choose to use 24-hour dietary recalls are encouraged to include estimates of the measure's reliability in a priori power calculations for improved decision making regarding the number of observations and/or sample size.

Impact of an equality constraint on the class-specific residual variances in regression mixtures: A Monte Carlo simulation study

Regression mixture models are a novel approach to modeling the heterogeneous effects of predictors on an outcome. In the model-building process, often residual variances are disregarded and simplifying assumptions are made without thorough examination of the consequences. In this simulation study, we investigated the impact of an equality constraint on the residual variances across latent classes. We examined the consequences of constraining the residual variances on class enumeration (finding the true number of latent classes) and on the parameter estimates, under a number of different simulation conditions meant to reflect the types of heterogeneity likely to exist in applied analyses. The results showed that bias in class enumeration increased as the difference in residual variances between the classes increased. Also, an inappropriate equality constraint on the residual variances greatly impacted on the estimated class sizes and showed the potential to greatly affect the parameter estimates in each class. These results suggest that it is important to make assumptions about residual variances with care and to carefully report what assumptions are made.

Identification of predicted individual treatment effects in randomized clinical trials

In most medical research, treatment effectiveness is assessed using the average treatment effect or some version of subgroup analysis. The practice of individualized or precision medicine, however, requires new approaches that predict how an individual will respond to treatment, rather than relying on aggregate measures of effect. In this study, we present a conceptual framework for estimating individual treatment effects, referred to as predicted individual treatment effects. We first apply the predicted individual treatment effect approach to a randomized controlled trial designed to improve behavioral and physical symptoms. Despite trivial average effects of the intervention, we show substantial heterogeneity in predicted individual treatment response using the predicted individual treatment effect approach. The predicted individual treatment effects can be used to predict individuals for whom the intervention may be most effective (or harmful). Next, we conduct a Monte Carlo simulation study to evaluate the accuracy of predicted individual treatment effects. We compare the performance of two methods used to obtain predictions: multiple imputation and non-parametric random decision trees. Results showed that, on average, both predictive methods produced accurate estimates at the individual level; however, the random decision trees tended to underestimate the predicted individual treatment effect for people at the extreme and showed more variability in predictions across repetitions compared to the imputation approach. Limitations and future directions are discussed.

The Results of the "Positive Action for Today's Health" (PATH) Trial for Increasing Walking and Physical Activity in Underserved African-American Communities

BACKGROUND

The "Positive Action for Today's Health" (PATH) trial tested an environmental intervention to increase walking in underserved communities.

METHODS

Three matched communities were randomized to a police-patrolled walking plus social marketing, a police-patrolled walking-only, or a no-walking intervention. The 24-month intervention addressed safety and access for physical activity (PA) and utilized social marketing to enhance environmental supports for PA. African-Americans (N=434; 62% females; aged 51±16 years) provided accelerometry and psychosocial measures at baseline and 12, 18, and 24 months. Walking attendance and trail use were obtained over 24 months.

RESULTS

There were no significant differences across communities over 24 months for moderate-to-vigorous PA. Walking attendance in the social marketing community showed an increase from 40 to 400 walkers per month at 9 months and sustained ~200 walkers per month through 24 months. No change in attendance was observed in the walking-only community.

CONCLUSIONS

Findings support integrating social marketing strategies to increase walking in underserved African-Americans (ClinicalTrials.gov #NCT01025726).

Regression Mixture Models: Does Modeling the Covariance Between Independent Variables and Latent Classes Improve the Results?

Regression mixture models are increasingly used as an exploratory approach to identify heterogeneity in the effects of a predictor on an outcome. In this simulation study, we tested the effects of violating an implicit assumption often made in these models; that is, independent variables in the model are not directly related to latent classes. Results indicate that the major risk of failing to model the relationship between predictor and latent class was an increase in the probability of selecting additional latent classes and biased class proportions. In addition, we tested whether regression mixture models can detect a piecewise relationship between a predictor and outcome. Results suggest that these models are able to detect piecewise relations but only when the relationship between the latent class and the predictor is included in model estimation. We illustrate the implications of making this assumption through a reanalysis of applied data examining heterogeneity in the effects of family resources on academic achievement. We compare previous results (which assumed no relation between independent variables and latent class) to the model where this assumption is lifted. Implications and analytic suggestions for conducting regression mixture based on these findings are noted.

Multilevel Associations of Neighborhood Poverty, Crime, and Satisfaction With Blood Pressure in African-American Adults

BACKGROUND

African-American adults experience the highest rates of elevated blood pressure (BP), and this disparity may be linked to socioeconomic and neighborhood-related disadvantage. Based on a bioecological stress-buffering framework, relations of poverty and neighborhood environmental perceptions with BP were assessed using multilevel regression in at-risk African-American adults.

METHODS

This cross-sectional study used baseline data that were collected in 2008 as part of the Positive Action for Today's Health (PATH) trial (N = 409), a community-based intervention to increase walking in low-income, high-crime neighborhoods. BP and perceived neighborhood crime and satisfaction were investigated as individual-level indicators of health and neighborhood environment. Census block groups (N = 22) served as geographic proxies for neighborhoods, and poverty was obtained using 2010 U.S. Census data, to characterize the neighborhood-level socioeconomic environment.

RESULTS

There were no individual-level direct associations. Significant cross-product interactions demonstrated that with higher perceived crime, high satisfaction was associated with lower systolic (γ = 3.34) and diastolic (γ = -1.37) BP, but low satisfaction was associated with higher systolic (γ = 15.12) and diastolic (γ = 7.57) BP. Neighborhood-level poverty was associated with diastolic (γ = 11.48, SE = 4.08, P = 0.008) and systolic BP (γ = 12.79, SE = 6.33, P = 0.052). Variance in BP across block groups was low (intraclass correlation coefficients = 0.002-0.014) and there were no significant random effects.

CONCLUSIONS

Results supported hypotheses, with greater neighborhood satisfaction linked to lower systolic and diastolic BP when perceived crime was high. Neighborhood poverty was also linked to higher systolic and diastolic BP. Prevention efforts should further investigate whether attending to issues of poverty and related neighborhood perceptions reduces high BP in at-risk African-American communities.

A multilevel approach to examining time-specific effects in accelerometer-assessed physical activity

OBJECTIVES

Popular methods for analyzing accelerometer data often use a single physical activity outcome variable such as average-weekly or total physical activity. These approaches limit the types of research questions that can be answered and fail to utilize the detailed, time-specific information available from accelerometers. This study proposes the use of multilevel modeling, which tested intervention effects at specific time periods.

DESIGN

The motivating example was the Active by Choice Today trial. Simulations were used to test whether the application of time-specific hypotheses about when physical activity intervention treatment effects were expected to occur (e.g., after-school hours) increased power to detect effects compared to traditional methods.

METHODS

Six simulation conditions were tested: (1) no treatment effects (to test the type 1 error rate), (2) time-specific effects, but no traditionally-tested effects, (3) traditionally-tested effects, but no time-specific effects, and (4) combinations of traditional and time-specific effects in 3 proportions.

RESULTS

Results showed the proposed multilevel approach demonstrated appropriate type 1 error rates and increased power to detect treatment effects during hypothesized times by 31-38 percentage points compared to traditional approaches. This was consistent across varying proportions of traditional versus time-specific effects, and there was no loss of power using the multilevel approach when only traditional effects were present.

CONCLUSIONS

The current study showed potential advantages of testing time-specific hypotheses about intervention effects using a multilevel time-specific approach. This approach may show intervention effects when traditional approaches do not. Future research should explore the application of this additional analytic tool for accelerometer physical activity estimates.

Using Multilevel Regression Mixture Models to Identify Level-1 Heterogeneity in Level-2 Effects

This paper proposes a novel exploratory approach for assessing how the effects of level-2 predictors differ across level-1 units. Multilevel regression mixture models are used to identify latent classes at level-1 that differ in the effect of one or more level-2 predictors. Monte Carlo simulations are used to demonstrate the approach with different sample sizes and to demonstrate the consequences of constraining 1 of the random effects to zero. An application of the method to evaluate heterogeneity in the effects of classroom practices on students is used to show the types of research questions which can be answered with this method and the issues faced when estimating multilevel regression mixtures.

Evaluating differential effects using regression interactions and regression mixture models

Research increasingly emphasizes understanding differential effects. This paper focuses on understanding regression mixture models, a relatively new statistical methods for assessing differential effects by comparing results to using an interactive term in linear regression. The research questions which each model answers, their formulation, and their assumptions are compared using Monte Carlo simulations and real data analysis. The capabilities of regression mixture models are described and specific issues to be addressed when conducting regression mixtures are proposed. The paper aims to clarify the role that regression mixtures can take in the estimation of differential effects and increase awareness of the benefits and potential pitfalls of this approach. Regression mixture models are shown to be a potentially effective exploratory method for finding differential effects when these effects can be defined by a small number of classes of respondents who share a typical relationship between a predictor and an outcome. It is also shown that the comparison between regression mixture models and interactions becomes substantially more complex as the number of classes increases. It is argued that regression interactions are well suited for direct tests of specific hypotheses about differential effects and regression mixtures provide a useful approach for exploring effect heterogeneity given adequate samples and study design.

Context-dependent pathways of the transmission of risk from communities to individuals

Research has consistently documented the role of environmental risk factors in the onset of delinquent behavior among youth. Less is known about the processes through which these contextual risks are translated to individual youth behavior. The aim of the current study is to examine the role of family risk factors in the transmission of community risk. Data was obtained from a nationally representative sample of over 30,000 middle school youth and community key informants (CKI). A multilevel, moderated mediation model was estimated with family risk as the moderator of the effect of CKI ratings of community risk on youth perceptions of risk. Results showed that when youth came from low risk families (measured by parental use of positive family management strategies), youth perceptions of risk mediated the effects of community risk on youth delinquency; however, there was no evidence of a significant mediated effect under conditions of high risk (measured by poor family management). This appears to be because youth from high-risk families perceived their neighborhoods as high-risk, regardless of actual levels of risk (as reported by CKI). This study finds that the relationship between communities and adolescent behavior is complex and interacts with the family environment.

Effects of the Communities That Care system on cross-sectional profiles of adolescent substance use and delinquency

INTRODUCTION

Adolescent substance use and delinquency are major public health problems. Although community-based prevention strategies have been recommended to produce population-level reductions in rates of substance use and delinquency, few models show evidence of effectiveness.

PURPOSE

To test the efficacy of a community-based prevention system, Communities That Care (CTC), in reducing community rates of problem behaviors, particularly effects on specific profiles of adolescent substance use and delinquency in eighth- and tenth-graders.

METHODS

Twenty-four communities were randomized to CTC intervention or control groups. Data were collected from 14,099 8th- and 10th-grade students in these communities using anonymous cross-sectional surveys in 2004 and 2010 and analyzed in 2012. Outcomes were four different profiles of self-reported substance use and delinquency in 8th grade and five profiles in 10th grade.

RESULTS

In the cross-sectional 2010 data, there was no intervention effect on the probability of experimenting with substances or of substance use coupled with delinquent activities for either grade. However, tenth-graders in intervention communities were significantly less likely to be alcohol users than those in control communities (OR=0.69, CI=0.48, 1.00).

CONCLUSIONS

Cross-sectional population surveys showed evidence of CTC effects in reducing tenth-grade alcohol users but not experimenters. A community-wide reduction in adolescent alcohol use is important because alcohol is the most commonly used illicit substance during adolescence, and early initiation of alcohol use has been associated with alcohol-related disorders in adulthood. Failure to find hypothesized effects on experimenters qualifies these results.

Finite Mixtures for Simultaneously Modelling Differential Effects and Non-Normal Distributions

Regression mixture models have been increasingly applied in the social and behavioral sciences as a method for identifying differential effects of predictors on outcomes. While the typical specification of this approach is sensitive to violations of distributional assumptions, alternative methods for capturing the number of differential effects have been shown to be robust. Yet, there is still a need to better describe differential effects that exist when using regression mixture models. The current study tests a new approach that uses sets of classes (called differential effects sets) to simultaneously model differential effects and account for non-normal error distributions. Monte Carlo simulations are used to examine the performance of the approach. The number of classes needed to represent departures from normality is shown to be dependent on the degree of skew. The use of differential effects sets reduced bias in parameter estimates. Applied analyses demonstrated the implementation of the approach for describing differential effects of parental health problems on adolescent body mass index using differential effects sets approach. Findings support the usefulness of the approach which overcomes the limitations of previous approaches for handling non-normal errors.

Differential Effects of Parental Controls on Adolescent Substance Use: For Whom Is the Family Most Important?

OBJECTIVE

Social control theory assumes that the ability of social constraints to deter juvenile delinquency will be invariant across individuals. This paper tests this hypothesis and examines the degree to which there are differential effects of parental controls on adolescent substance use.

METHODS

Analyses are based on self-reported data from 7,349 10th-grade students and rely on regression mixture models to identify latent classes of individuals who may vary in the effects of parental controls on drug use.

RESULTS

All parental controls were significantly related to adolescent drug use, with higher levels of control associated with less drug use. The effects of instrumental parental controls (e.g., parental management strategies) on drug use were shown to vary across individuals, while expressive controls (e.g., parent/child attachment) had uniform effects in reducing drug use. Specifically, poor family management and more favorable parental attitudes regarding children's drug use and delinquency had stronger effects on drug use for students who reported greater attachment to their neighborhoods, less acceptance of adolescent drug use by neighborhood residents, and fewer delinquent peers, compared to those with greater community and peer risk exposure. Parental influences were also stronger for Caucasian students versus those from other racial/ethnic groups, but no differences in effects were found based on students' gender or commitment to school.

CONCLUSIONS

The findings demonstrate support for social control theory, and also help to refine and add precision to this perspective by identifying groups of individuals for whom parental controls are most influential. Further, they offer an innovative methodology that can be applied to any criminological theory to examine the complex forces that result in illegal behavior.