Stefany Coxe

Statistical Power to Detect the Correct Number of Classes in Latent Profile Analysis

Little research has examined factors influencing statistical power to detect the correct number of latent classes using latent profile analysis (LPA). This simulation study examined power related to interclass distance between latent classes given true number of classes, sample size, and number of indicators. Seven model selection methods were evaluated. None had adequate power to select the correct number of classes with a small (Cohens d = .2) or medium (d = .5) degree of separation. With a very large degree of separation (d = 1.5), the Lo–Mendell–Rubin test (LMR), adjusted LMR, bootstrap likelihood ratio test, Bayesian Information Criterion (BIC), and sample-size-adjusted BIC were good at selecting the correct number of classes. However, with a large degree of separation (d = .8), power depended on number of indicators and sample size. Akaikes Information Criterion and entropy poorly selected the correct number of classes, regardless of degree of separation, number of indicators, or sample size.

Economic hardship, neighborhood context, and parenting: Prospective effects on Mexican American adolescent’s mental health

This study examined family and neighborhood influences relevant to low-income status to determine how they combine to predict the parenting behaviors of Mexican–American mothers and fathers. The study also examined the role of parenting as a mediator of these contextual influences on adolescent internalizing and externalizing symptoms. Study hypotheses were examined in a diverse sample of Mexican–American families in which 750 mothers and 467 fathers reported on their own levels of parental warmth and harsh parenting. Family economic hardship, neighborhood familism values, and neighborhood risk indicators were all uniquely associated with maternal and paternal warmth, and maternal warmth mediated the effects of these contextual influences on adolescent externalizing symptoms in prospective analyses. Parents’ subjective perceptions of neighborhood danger interacted with objective indicators of neighborhood disadvantage to influence maternal and paternal warmth. Neighborhood familism values had unique direct effects on adolescent externalizing symptoms in prospective analyses, after accounting for all other context and parenting effects.

Six-Year Longitudinal Predictors of Posttraumatic Growth in Parentally Bereaved Adolescents and Young Adults

Using the Posttraumatic Growth Inventory, we examined posttraumatic growth in a sample of 50 adolescents and young adults who had experienced parental death in childhood or adolescence. Longitudinal relations were examined between baseline measures of contextual and intraindividual factors and scores on the posttraumatic growth subscales (i.e., New Possibilities, Relating to Others, Personal Strengths, Spiritual Changes, and Appreciation of Life) six years later. Controlling for time since death, threat appraisals, active coping, avoidant coping, seeking support from parents or guardians, seeking support from other adults, internalizing problems, and externalizing problems were significant predictors of posttraumatic growth. The implications of these findings for research and clinical practice are discussed.

Treatment Sequencing for Childhood ADHD: A Multiple-Randomization Study of Adaptive Medication and Behavioral Interventions

Behavioral and pharmacological treatments for children with attention deficit/hyperactivity disorder (ADHD) were evaluated to address whether endpoint outcomes are better depending on which treatment is initiated first and, in case of insufficient response to initial treatment, whether increasing dose of initial treatment or adding the other treatment modality is superior. Children with ADHD (ages 5–12, N = 146, 76% male) were treated for 1 school year. Children were randomized to initiate treatment with low doses of either (a) behavioral parent training (8 group sessions) and brief teacher consultation to establish a Daily Report Card or (b) extended-release methylphenidate (equivalent to .15 mg/kg/dose bid). After 8 weeks or at later monthly intervals as necessary, insufficient responders were rerandomized to secondary interventions that either increased the dose/intensity of the initial treatment or added the other treatment modality, with adaptive adjustments monthly as needed to these secondary treatments. The group beginning with behavioral treatment displayed significantly lower rates of observed classroom rule violations (the primary outcome) at study endpoint and tended to have fewer out-of-class disciplinary events. Further, adding medication secondary to initial behavior modification resulted in better outcomes on the primary outcomes and parent/teacher ratings of oppositional behavior than adding behavior modification to initial medication. Normalization rates on teacher and parent ratings were generally high. Parents who began treatment with behavioral parent training had substantially better attendance than those assigned to receive training following medication. Beginning treatment with behavioral intervention produced better outcomes overall than beginning treatment with medication.

Six-year follow-up of a preventive intervention for parentally bereaved youths: A randomized controlled trial

OBJECTIVE To evaluate the efficacy of the Family Bereavement Program (FBP) to prevent mental health problems in parentally bereaved youths and their parents 6 years later. DESIGN Randomized controlled trial. SETTING Arizona State University Prevention Research Center from November 2002 to July 2005. PARTICIPANTS Two hundred eighteen bereaved youths (89.34% of 244 enrolled in the trial 6 years earlier) and 113 spousally bereaved parents. INTERVENTIONS The FBP includes 12 group sessions for caregivers and youths; the literature control (LC) condition includes bereavement books for youths and caregivers. MAIN OUTCOME MEASURES Comparisons of youths in the FBP and LC on a measure of mental disorder diagnosis, 5 measures of mental health problems, and 4 measures of competent functioning; and comparisons of spousally bereaved parents on 2 measures of mental health problems. RESULTS Youths in the FBP as compared with those in the LC had significantly lower externalizing problems as reported by caregivers and youths (adjusted mean, -0.06 vs 0.13, respectively; P = .02) and on teacher reports of externalizing problems (adjusted mean, 52.69 vs 56.27, respectively; P = .001) and internalizing problems (adjusted mean, 47.29 vs 56.27, respectively; P = .002), and they had higher self-esteem (adjusted mean, 33.93 vs 31.91, respectively; P = .005). Parents in the FBP had lower depression scores than those in the LC (adjusted mean, 5.48 vs 7.83, respectively; P = .04). A significant moderated program effect indicated that for youths with lower baseline problems, the rate of diagnosed mental disorder was lower for those in the FBP than in the LC. CONCLUSION This study demonstrates efficacy of the FBP to reduce mental health problems of bereaved youths and their parents 6 years later. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01008189.

The role of early childhood ADHD and subsequent CD in the initiation and escalation of adolescent cigarette, alcohol, and marijuana use.

Adolescents with attention deficit/hyperactivity disorder (ADHD) are at an increased risk for substance use but the pathways through which this risk emerges are insufficiently understood. Tobacco, alcohol, and marijuana outcomes were compared between adolescents diagnosed with ADHD in early childhood (N = 113) and demographically similar controls (N = 65). Participants were assessed from age 5 until age 18. A comprehensive history of adolescent substance use was compiled for each participant and growth in ADHD and conduct disorder (CD) were modeled as they related to substance use outcomes. Results indicated that when compared with controls, adolescents with ADHD were more likely to try cigarettes, initiate alcohol use at early ages, and smoke marijuana more frequently. Furthermore, adolescents with ADHD were 4 to 5 times more likely than controls to escalate to heavy cigarette and marijuana use after trying these substances once. Adolescents with ADHD who escalated to heavy use patterns were more likely to display early cigarette use and marked problems with family members, but displayed fewer peer problems. There was evidence of baseline effects (latent intercept, measured at age 5) for both ADHD and CD on substance use outcomes. Furthermore, growth in ADHD symptoms accounted for much of the growth in CD symptoms, and consequently, escalating CD symptoms in childhood (latent slope) were viewed as a mediator of the relationship between ADHD and cigarette and marijuana use. Maternal drinking in early childhood was the strongest predictor of early adolescent alcohol use. These findings are discussed with respect to the role of ADHD in the development of adolescent risk outcomes.

Neighborhood Disadvantage, Stressful Life Events, and Adjustment among Mexican American Early Adolescents.

This study examined a stress process model in which stressful life events and association with delinquent peers mediated the relationship of neighborhood disadvantage to Mexican American early adolescents’ mental health. The authors also proposed that child gender, child generation, and neighborhood informal social control would moderate the relationship of neighborhood disadvantage to children’s experiences of stressful life events. With data from 738 Mexican American early adolescents, results generally provided support for the theoretical model although the relationships of neighborhood disadvantage to stressful life events and adjustment were weaker than expected. Additional research is needed to corroborate these results and determine why neighborhood disadvantage may have different relationships to adjustment for Mexican American early adolescents than for others.

Comparative Cost Analysis of Sequential, Adaptive, Behavioral, Pharmacological, and Combined Treatments for Childhood ADHD

We conducted a cost analysis of the behavioral, pharmacological, and combined interventions employed in a sequential, multiple assignment, randomized, and adaptive trial investigating the sequencing and enhancement of treatment for children with attention deficit hyperactivity disorder (ADHD; Pelham et al., 201X; N = 146, 76% male, 80% Caucasian). The quantity of resources expended on each child’s treatment was determined from records that listed the type, date, location, persons present, and duration of all services provided. The inputs considered were the amount of physician time, clinician time, paraprofessional time, teacher time, parent time, medication, and gasoline. Quantities of these inputs were converted into costs in 2013 USD using national wage estimates from the Bureau of Labor Statistics, the prices of 30-day supplies of prescription drugs from the national Express Scripts service, and mean fuel prices from the Energy Information Administration. Beginning treatment with a low-dose/intensity regimen of behavior modification (large-group parent training) was less costly for a school year of treatment (

Long-Term Effects of a Universal Family Intervention: Mediation Through Parent-Adolescent Conflict

961) than beginning treatment with a low dose of stimulant medication (

Analyzing count variables in individuals and groups: Single level and multilevel models:

1,669), regardless of whether the initial treatment was intensified with a higher “dose” or if the other modality was added. Outcome data from the parent study (Pelham et al., 201X) found equivalent or superior outcomes for treatments beginning with low-intensity behavior modification compared to intervention beginning with medication. Combined with the present analyses, these findings suggest that initiating treatment with behavior modification rather than medication is the more cost-effective option for children with ADHD.