Multi-level Effects of a Parenting Intervention for Enhancing Latino Youth Health Behaviors
Phase: NA
Conditions: Diet Modification, Substance Use Disorders, Diabetes Mellitus Risk, Cardiovascular Risk Factor, Lifestyle Risk Reduction, Parenting
Sponsor: Arizona State University

 
 
 
Study Protocol 
 
The Impact of a Parenting Intervention on Latino Youth Health 
Behaviors (FPNG+) 
NCT03517111 
 
 
May 15, 2023 
 
 

The Impact of a Parenting Intervention on Latino Youth Health Behaviors (FPNG+) 
 
Introduction 
 
The NIMHD-funded Families Preparing the New Generation (FPNG) is a 10-workshop efficacious 
parenting intervention to increase parent-child communication and family functioning as a means to 
prevent substance use in Latino youth.1,2  Each parent workshop is 2.5 hours in length and is usually 
offered on a weekly basis.  Based upon feedback from FPNG community partners, there is a pressing 
need to integrate healthy nutrition into the FPNG curriculum in order to make a greater impact on the 
health needs of Latino youth.  Thus, the overall objective of the current application is to build upon the 
success of FPNG to promote healthy nutrition and reduce substance use among Latino youth.  Our long 
term-goal is to help reduce health disparities observed among Latino youth through culturally grounded 
interventions that target nutrition as well as the prevention of tobacco use and other substances.  Our 
central hypothesis is that by strengthening the parent-child communication and family functioning, it is 
possible to simultaneously impact two health behaviors (nutrition and substance use) among Latino 
youth and positively improve multiple health outcomes. 
 
The proposed study will extend the scope of FPNG by creating an enhanced parenting intervention 
(FPNG+) that will promote healthy nutrition while sustaining its efficaciousness in youth substance use 
prevention using an ecological framework.  The first phase of the proposed study will use a community-
based participatory research (CBPR) approach3 in partnership with Latino communities to extend the 
scope of the FPNG intervention and identify culturally-acceptable ways to weave nutrition improvement 
strategies into the existing parenting intervention.  This will allow us to address multi-level social 
determinants of health that are common to substance use prevention and healthy nutrition promotion.  
The second phase will test the efficacy of the enhanced intervention over time through a 3-arm 
randomized controlled trial comparing FPNG+ (substance use prevention and healthy nutrition), FPNG 
(substance use prevention only), and a comparison condition (focusing on academic success).  The 
transdisciplinary team will have a CBPR orientation and will apply qualitative methods, survey research 
methods, and biomarkers to measure change in nutrition and substance use outcomes over time among 
youth and parents.  
 
Study design 
 
In this 3-arm randomized controlled trial (RCT), parent-child dyads will be assigned to a 10-week group-
based intervention, delivered to parents, targeting adolescent substance use prevention and diet 
improvement through parenting and family-focused strategies.  The proposed study will be conducted in 
partnership with our longtime research collaborator, the ADA.  ADA has a demonstrated record of 
successfully recruiting and retaining thousands of Mexican heritage and other Latino parents into 
Realizing the American Dream (RAD), their academic success program with no substance use prevention 
or nutrition content.  ADA’s trained community facilitators will lead the parents’ groups (15 parents per 
group) via three conditions: substance use prevention and healthy nutrition (FPNG+; n=498 parent-child 
dyads); substance use prevention only (FPNG; n=498 parent-child dyads), or a comparison condition 
(RAD; n=498 parent-child dyads).  The three curricula will be delivered through ADA programming, 
offered to families of 6th – 8th grade students (11-14 years old) in 18 different schools (6 per condition).  
Randomization will occur at the school level, each school randomly assigned to one of the three 
conditions.  Participants will be consented for the specific condition their school is randomized to (i.e. 
the consenting materials will only describe the condition the school is assigned to). 
 

Participant recruitment 
 
We will recruit parent-child dyads consisting of one parent and one youth enrolled in 6th, 7th or 8th grade.  
Following inclusiveness policies from our community partner, the American Dream Academy (ADA), 
parents of children enrolled in other grades will also be included if interested in the program, but their 
children will not be part of the study.  Inclusion criteria are as follows: 
Youth: 
• 
ages 11-14 
• 
enrolled in 6th -8th grade at the time of recruitment from the ADA programs 
 
Adults: 
• 
age 18 or older 
• 
parent/caregiver/guardian of an eligible youth or parent of a child enrolled in participating 
schools who expresses interest in the program 
 
We will provide ADA with general “invitation scripts” to be used by the trained operators of the ADA 
phone call center describing the study and inviting parents and their children to attend an information 
session. Parents will be asked to bring their middle school grade child to the information session they 
attend. The next step in recruitment will be more targeted and will consist of phone calls to 6th-8th grade 
parents in an effort to maximize the number of participants with children in the target grades (6th, 7th, 
8th). The ADA phone call center operators will read the script to parents according to the random 
assignment of each recruitment site.  During the information session, trained bilingual study staff will 
provide an explanation of the study and answer questions prior to obtaining written consent.  Parent-
child dyads who are interested in participating will be asked to stay at the end for a consenting session 
during which the consent form will be read and explained, questions will be asked, and written consent, 
parental permission, and child assent will be collected.  All parents of 6th, 7th , or 8th  grade students will 
be asked to give their adolescent permission to participate in the study (data collection only). In 
addition, each youth will be invited to assent to each of the procedures, in addition to and separate 
from parental permission. We will not collect data from children who are not in 6th, 7th or 8th grades, 
even if their parents participate in the study. Participants will be enrolled in the study for approximately 
8 months to allow for data collection and delivery of a 10-week intervention of individual workshops of 
2.5 hours each. All data will be collected at baseline (T1), immediately post-intervention (T2), and at 
approximately 16 weeks post-intervention (T3). It is anticipated that a noteworthy majority of youth and 
adult participants will represent minority populations. 
 
Self-identified Latino families (determined by their response on the survey question regarding ethnicity) 
with 6th, 7th or 8th grade children will be eligible to participate in an exploratory sub-study involving data 
collection through a home visit. To create the subsample of parents and youth who will participate in 
additional data collection for the exploratory aim, of those parents who choose to provide personal 
consent and child permission for surveys, for each of the three conditions, we will randomly select 9 
self-identified Latino families per school (determined by their response on the survey question regarding 
ethnicity) to participate in all exploratory data collection procedures (finger prick; weight, height and 
blood pressure; 24 hour Food Recall; household food inventory). Because parents will have the choice to 
consent to these additional procedures, we will create a randomly selected mirror sample of an 
additional 9 self-identified families (determined by their response on the survey question regarding 
ethnicity) per school. If one of the original 9 parents chooses not to participate in these additional data 
collection procedures, we will randomly select a family from the mirror sample. This procedure will 
continue until we have 9 families per school (from each of all three conditions) who agree to participate 

in all phases of data collection. Families in the mirror sample will not be contacted by the research team 
unless an original family chooses not to participate. 
 
Data collection 
 
Data collection from both parents and youth will take place at baseline (T1), immediately post-
intervention at 10 weeks (T2), and at approximately 16 weeks post-intervention (T3).  All parents and 
youth will be asked to complete a survey to collect information on substance use and nutrition 
outcomes (see Measures) regardless of intervention condition at the youth’s school. 
  
Additional data will be gathered from a random subsample of self-identified Latino 126 families (42 per 
condition) at the same time points (T1, T2 and T3) to explore the preliminary effects of FPNG+ on 
modifiable chronic disease risk factors and the home food environment (see Measures).  This data 
collection home visit is anticipated to last 90 minutes during which the following procedures will take 
place: (1) measurement of parent and child body weight, height, and blood pressure; (2) collection of a 
finger prick blood sample from parent and child for measurement of HbA1c and total cholesterol using 
portable point-of-care devices; (3) and completion of a home food inventory to record availability of 
fruit, vegetables, and sugar-laden foods.  Because blood will be collected from a finger prick, we will only 
collect the necessary amount of blood to perform the proposed analysis (three to four drops) on site by 
using it directly into the measuring device (similar to glucometers used by patients with diabetes).  The 
reactive strips used with the measurement instruments will be discarded immediately after they are 
used.  No blood samples will be stored. The 24 hour Food Recall questionnaire will be done over the 
phone for both parents and youth. As part of the 24 hour Food Recall, parents will answer a short 
questionnaire regarding some of the food details that their child may not know, such as the type of oil 
they buy, what kind of fat they use for cooking, and the types of bread and milk they typically buy for 
the family. 
 
Measures 
 
Survey.  Self-administered surveys will be available in Spanish and English so the respondent can 
complete it in the language he/she chooses without needing to request the accommodation. If 
participants cannot read in either language, a Research Assistant will read the questions to them.  All 
constructs will be measured at all three time points (T1, T2 and T3) with the exception of 
sociodemographic characteristics. 
 
The survey will include items from our prior substance use prevention evaluations with Mexican 
heritage youth4 supplemented by measures of participants’ family functioning and cultural orientations.  
Outcomes include recent use of substances (amount and frequency of alcohol, cigarettes, marijuana, 
and inhalants),5  drug resistance strategies,6 intake of fruit, vegetable, and sugar-laden foods, assessed 
with the NCI Dietary Screener Questionnaire,7 family functioning,8 familism,9 parenting skills,10-15 social 
support,16 acculturation,17 food insecurity,18,19 and resiliency.20  
 
We will let parents and youth know, on the consent and assent forms, that we may need to contact 
them to clarify write-in answers on the NCI Dietary Screener Questionnaire. Specifically, participants are 
asked to write in the brand and type of cereals consumed and they sometimes provide ambiguous 
information (e.g., Kellogg’s). Given that this information is needed to assess the overall dietary screener 
score, we will contact participants if their responses do not provide specific information about the type 
of cereal consumed. 

 
Anthropometric measurements.  Body weight and height of parents and youth will be collected in 
triplicate using light indoor clothing without shoes, using a standardized protocol.  BMI for adults will be 
calculated in kg/m2. For youth, weight and height will be used to determine BMI percentiles for age and 
sex based upon the 2000 CDC growth curves. 
 
Cardiometabolic disease risk factors.  Participants’ (parents and youth) blood pressure will be measured 
in triplicate using an automated blood pressure monitor (Omron IntelliSense HEM-907XL; Omron 
Healthcare, Inc.; Bannockburn, IL).  A finger prick blood sample will be collected from parents and youth 
to measure total cholesterol and HbA1c.  This method was selected instead of venipuncture to reduce 
participant burden.   
 
We decided to measure HbA1c as a marker of diabetes risk instead of fasting glucose to avoid the need 
for fasting blood sample collection.  This will lower participant burden and increase our ability to collect 
samples from all participants in the subsample.  Although it is recommended to measure fasting 
cholesterol to assess cardiovascular disease risk, it has been documented that non-fasting total 
cholesterol concentrations also predict cardiovascular events because concentration changes are 
minimal in response to normal food intake.21  Similarly, fasting glucose may not be a robust indicator of 
type 2 diabetes risk in the pediatric population,22 whereas HbA1c shows promise as a screening indicator 
for diabetes risk in youth.23  Recently, HbA1c is been shown to prospectively predict the development of 
type 2 diabetes in youth24 and may closely mirror dysglycemia under free-living physiologic conditions in 
youth.25 
 
Detailed nutrition variables of interest (energy, macronutrients, consumption of sugar-sweetened 
beverages, added sugars, servings of fruits and vegetables, and whole grains) from youth and parents 
will be obtained using two 24-hour Food Recalls, conducted in either English or Spanish. Participants will 
be asked to recall all of the food they consumed in the past day.   
  
Home food environment.  We will use a modified version of the validated Home Food Inventory26 to 
assess availability and variety of fruit, vegetables, sugar-containing foods and beverages, snack foods, 
and breakfast cereals in the home.  Modifications included cultural adaptations to include foods 
commonly consumed by Latinos (e.g., pan dulce, papaya, cactus pads), and inclusion of breakfast 
cereals.  Although this instrument was developed for self-report, we will utilize research staff for data 
collection to minimize self-report bias. 
 
Data Management Plan 
 
The data management goals are to ensure that (a) data are accurately collected, entered, and 
documented; (b) data are stored in an electronic format that will allow investigators to retrieve data 
easily and export data for statistical analysis; and (c) participant information remains confidential.  Prior 
to data collection and entry, a codebook containing all variable names, descriptions, and value codes will 
be created. Only trained study personnel will have access to the data. Focus group and intervention data 
will be entered promptly after collection, and database entries from a random subset of 20% of the data 
will be audited to ensure data quality.  We will conduct periodic data quality checks, including 
descriptive statistics.  All study-related materials and data will be stored in locked cabinets or password-
protected computers.  Databases will only include de-identified data by using ID numbers only. Not sure 
if we should add something here about following up with them for the cereal question. 

The PI, study coordinator, or a designated trained bilingual staff member will be responsible for 
explaining the study, answering questions, and obtaining written or verbal informed consent from 
parents and written assent from youth during information sessions at participating schools.  Verbal 
consent from adults will be offered as an option only if the parent is interested and unable to attend in 
person to consent. Study personnel will reach out to them by phone.  All procedures will be explained to 
potential participants in detail in their preferred language (English or Spanish).  Special attention will be 
taken to properly explain the assent document in detail to youth to ensure comprehension.  Consent 
and assent forms will be available in English and Spanish.  Because randomization will occur at the 
school level, participants will be consented for the specific condition their school is randomized to (i.e. 
the consenting materials will only describe the condition the school is assigned to). 
 
Data Analysis Plan 
 
Power calculations considered design effects related to the clustering of outcome means by school sites. 
The total estimated sample size is 1494 parent-child dyads, across 18 schools. Based on data from the 
FPNG effectiveness trial, the level of clustering is low for our outcomes, including an intraclass 
correlation equal to 0.01, a student level R-square of 0.25, and a school level R-square of 0.03.2 Because 
the effect size for substance use outcomes (d=0.20; FPNG vs. C) is lower than the expected effect size for 
nutrition outcomes (d=0.78; prior non-related intervention study), the total sample size is calculated for 
substance use outcomes. Accounting for these parameters, the power of this design is 0.802. For the 
subsample, the estimated sample size is 126 households across 18 schools – 7 per school. The average 
effect size of .69 is calculated based upon prior work on home food availability of vegetables, fruits, and 
desserts. Given the above stated parameters, the power of this design is 0.814. 
 
All analyses will be conducted using multilevel analyses in Mplus,27 with families clustered within 
schools.  This analysis accounts for the clustering which, if uncorrected, may result in biased standard 
errors.28  All analyses will employ a robust maximum likelihood estimator to adjust for any non-
normality in the distributions of outcomes and to best control for Type I errors.29 The analyses will also 
utilize full-information maximum likelihood (FIML)30 to conduct intent-to-treat analyses that account 
and adjust for attrition and any item missing data. 
 
We will use both baseline adjusted general linear model procedures (i.e., variants of multiple regression) 
and latent change modeling to test intervention efficacy. In all models, because the FPNG Plus is the 
intervention condition of interest, all analyses will use FPNG Plus as the reference group. The two 
remaining conditions (FPNG and Comparison) will be compared with the reference group.  The first 
method will predict short-term (T2) and then long-term (T3) post-test outcome measures (e.g., 
adolescents substance use and diet outcomes), while controlling simultaneously for the baseline (T1) 
measure of the particular outcome. Latent-change models31 will test whether and how changes over 
time in the outcomes differ significantly.  Latent-change models will enable the assessment of change 
between T1 and T2 separately from change between T2 and T3.  This examination will simultaneously 
test for improvements manifested during the course of the intervention (i.e., between T1 and T2) and 
for improvements maintained following the completion of the intervention (i.e., between T2 and T3).  
For mediation analyses, we will employ multivariate linear regression path analyses.32,33  Each mediation 
model will test the indirect path between the intervention condition at T1 and outcome measures at T3 
(e.g., adolescents substance use and nutrition outcomes) mediated through family functioning, 
parenting strategies, and parents’ social support at T2.  Mediation models will control for baseline (T1) 
measures of the particular mediator and outcome.  We will employ a bias-corrected bootstrap approach 
to test the indirect effect.34 

 
The moderation effects of sociocultural factors on outcome measures will be tested employing mean 
centered interactions of the measures of acculturation, acculturative stress, food insecurity, and 
resiliency with the dummy variable contrasts of intervention conditions, following Aiken & West 
(1991).35  We will use baseline adjusted general linear model procedures to test for moderation. If 
significant moderation exists, we will use latent-change models to test whether and how changes over 
time in the outcomes differ significantly between adolescents who vary in the sociocultural moderating 
measures of interest (e.g., for those adolescents who are less and more acculturated). 
Intervention effects on cardiometabolic risk factors and home food environment outcomes measured in 
the subsample will be tested through baseline adjusted regression models, including models that can 
appropriately analyze count data (e.g., Poisson, Negative Binomial). We will examine changes in short-
term (T2) and long-term (T3) outcomes with dummy variable contrasts of intervention conditions, while 
controlling simultaneously for the baseline (T1) measure of the particular outcome. 
 
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