Linking Primary Care, Communities and Families to Prevent Obesity Among Preschoolers
Phase: NA
Conditions: Childhood Obesity
Sponsor: University of Minnesota

1 
 
COPTR Preparation for Primary Analysis 
 
INTRODUCTION 
Determination of the effect of an intervention on the primary outcome is usually the most 
important analysis in a randomized trial.  Therefore, the COPTR investigators have carefully 
specified the statistical analysis plans for the primary outcome for each of the 4 field site 
studies.  Analysis plans were reviewed and approved by the DSMB in April, 2012 as a part of 
the review of the study protocols.  More recently, the COPTR investigators have taken 
additional steps to ensure full and detailed specification of variable definitions and the analytic 
plans that will be used in the final analyses.   
 
The process undertaken involved the simulation of data in which the final primary outcome 
analysis could be rehearsed.  The variables to be used in the analysis and imputation of missing 
data (when applicable) were defined and constructed.  Analytic code was written independently 
by investigators at study sites and the RCU, analyses were conducted using simulated data, 
and results were compared.  If differences were identified the code from the RCU and the site 
were compared by an independent programmer and adjudicated.  Following this process, the 
results from the study sites and from the RCU were, for practical purposes, identical.   
 
This primary outcome analysis rehearsal has served as a vehicle to expose detailed decisions 
and adjustments that needed to be made in analysis plans.  The Steering Committee 
acknowledges that ideally every aspect of the primary analysis would be established before the 
study begins.  However, our protocols, while detailed, did not address every nuance of the 
analysis and the imputation of missing data.  In addition, there can be unanticipated changes in 
study implementation that invoke refinement of the data analysis plan. It is important to note 
that, at the time of this report, masking remains firmly in place.  All personnel at the sites, 
including the site statisticians, signed written statements masking them to all analyses by arm.   
 
To support full transparency, we have prepared a summary of the adjustments, clarifications 
and specifications made to statistical analysis plans during the course of this project (section A), 
followed by the final revised analysis plan (section B). Revisions to the analysis plans approved 
in April of 2012 are shown as tracked changes.  The descriptions address only the primary 
analysis and, unless relevant to the revised analysis, we have removed from the text below 
details related to assumptions, power calculations, and secondary and sensitivity analyses.  
Deletions were not tracked, but the removal of this type of text is denoted by 3 stars (* * *). 
The plans shown below were endorsed by the Steering Committee with 5 votes in favor and one 
abstention.  The NHLBI abstained because of concerns about the Vanderbilt change in the 
primary outcome test.  More details on this discussion are shown below in Section 4 and in the 
addendum.   
 
The preliminary work on the primary analysis done by the COPTR investigators was more 
extensive than that usually conducted in trials.  The construction of simulated data and the 
implementation of planned analyses exposed details and concerns that otherwise may not have 
been addressed until after the blind was broken.  We are confident that the expanded process 
of preliminary analyses conducted by the COPTR investigators will expedite the time required to 
move the COPTR primary outcomes analyses to full publication.   
 
 

2 
 
 
UNIVERSITY OF MINNESOTA 
A2: Summary of adjustments, clarifications and specifications 
 
The primary analysis will not include a random effect for ECFE cohort membership. 
At the time the original SAP was approved by the DSMB, it was our intention that 
consistent and identifiable cohorts of families would attend a series of Early 
Childhood and Family Education (ECFE) classes together over the duration of 
the intervention. This component of the NET-Works intervention did not 
materialize as intended. ECFE participation was lower than expected and there 
are not identifiable or consistent groups of families that attend these classes.  
 
 
The primary analysis will include a random effect for Family Connector (FC) assignment  
It was observed that the home visit component of the NET-Works intervention 
was delivered to N=257 out of N=265 intervention group families by 7 family 
connectors. Because it is possible that characteristics of particular FCs may be 
related to BMI outcomes of the families to which they are assigned, we 
determined that it would be prudent to model this potential source of dependency 
in the primary outcome.  
The decision to omit the random ECFE term and estimate a random FC term was 
made after study recruitment was complete and sample size was therefore fixed.  
 
 
Family Connector specification  
The method for coding the Family Connector was not previously specified.  
Seven FCs delivered the home visit intervention component to 257 of the 265 
treatment group families. Each of these 257 families will be assigned to a FC 
group based on the primary FC with whom they worked. Treatment group 
families that did not participate in the home visit intervention component, and all 
control group families, will be assigned to their own n=1 FC group. 
  
 
Multiple imputation specifications  
We indicated previously that variables from the analytic model as well as 
auxiliary variables and interactions would be used in the imputation model.  We 
have now specified a list of 9 candidate auxiliary variables and decided not to 
include interactions. We also provide more specificity regarding the number of 
datasets to be imputed (minimum 20) and the principles guiding decisions about 
the imputation process.   
 
 
B2: Revised Analysis Plan 
 
2.1. Study Design 
The study is an individually randomized group trial. Families will be randomized equally to the 
NET-Works intervention or a control group. The NET-Works intervention duration is thirty-six 
months. Outcome measures will be assessed at baseline and at 12, 24 and 36 months post-
randomization. 
 
 

3 
 
2.2. Primary Research Question and Hypothesis 
Specific Aim 1 
To evaluate the effects of a three-year multi-setting parent-targeted randomized controlled 
intervention on the primary outcome, child BMI, compared to a standard primary care-only 
intervention among low income ethnic minority two to four year old children who are at or above 
the 50th percentile of BMI for age and gender.  
Hypothesis 1: Children in the multi-setting parent-targeted intervention will have a lower BMI at 
24 and 36 months, compared with children in the standard primary care only control group. 
* * * 
2.4. Primary Analysis 
2.4.1. Statistical model and approach 
The primary analysis will test whether NET-Works participants have lower BMI at 24 and 36 
months relative to comparison participants. We will use data from all randomized participants 
(intent to treat approach) to estimate two mixed models in which 24 or 36 month BMI values are 
predicted from randomized treatment group with age group at baseline, sex and BMI at baseline 
as covariates, and a random intercept for family connector (u0j): 
BMIij = γ00 + γ01NET-Worksj +  
γ203yoi + γ304yoi + γ40femalei + γ50BMI baselinei + [u0j + eij]. 
We will conclude that NET-Works was efficacious if the γ01 parameter in both mixed models is 
statistically significant and negative, meaning that BMI is significantly lower among NET-Works 
children than comparison children. 
* * * 
A source of dependence lies in the family connector (FC) assignment. Seven family connectors 
delivered the home visit component of NET-Works to intervention families. To the extent FC 
assignments were intended to be culture-specific, and FCs may vary slightly in their manner of 
delivering intervention content to the families with whom they work, dependence may be 
introduced through common FC assignment. As such, it will be important to account for 
dependence in BMI introduced through FC assignment. 
* * * 
Each of the families will be assigned to a FC group based on the primary FC with whom they 
worked. Treatment group families that did not participate in the home visit intervention 
component, and all control group families, will be assigned to their own n=1 FC group following 
the method of Esserman et al. (2012). 
2.4.3. Missing data including level of attrition, loss to follow-up, and missing data 
treatment 
* * * 
The primary analysis will be conducted using multiply imputed data. We plan to use fully 
conditional specification to impute sporadically missing followed by 12, 24 and 36 month 
monotonically missing BMI values. We anticipate imputing a minimum of 20 datasets based on 
the observed missingness to date in post-baseline BMI values but may upwardly adjust this 
number to ensure adequate power (Graham et al., 2007). The imputation model will include the 

4 
 
primary analytic model covariates (child gender, child age at randomization, baseline BMI, 
treatment group) as well as auxiliary variables. Candidate auxiliary variables include child race / 
ethnicity, primary parent education, highest parental education, household income, family 
connector, parent BMI and 12m, 24m and 36m BMI. Some of the candidate auxiliary variables 
may be culled in consideration of factors such as the ratio of complete cases to estimated 
parameters and the degree of correlation with the outcome (Hardt et al., 2012). All analytic 
model covariates will have been documented prior to randomization with no missing values. 
Candidate auxiliary variables, excepting post-baseline BMI values and family connector, will 
have been measured at baseline with minimal missing values. The imputation model 
parameters may need to be calibrated in a manner that departs from the aforementioned 
expectations (i.e., number of imputations, number of iterations between datasets, number and 
coding of auxiliary variables). Model calibration will be informed by extant literature and guided 
by sensitivity analyses to arrive at a stable imputation model. The significance of the combined 
treatment parameter will not be a consideration in guiding imputation model decisions.  
* * * 
 

NET-Works: Linking families, communities and primary care to
prevent obesity in preschool-age children☆,☆☆
Nancy E. Sherwood a,⁎, Simone A. French b,1, Sara Veblen-Mortenson b,1, A. Lauren Crain a,2,
Jerica Berge c,3, Alicia Kunin-Batson a,2, Nathan Mitchell b,1, Meghan Senso a,b,1,2
a HealthPartners Institute for Education and Research, 8170 33rd Ave. S., Mail stop 21111R, PO Box 1524, Bloomington, MN 55440-1524, USA
b Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, West Bank Ofﬁce Building, 1300 South Second St., Suite 300,
Minneapolis, MN 55454, USA
c Department of Family Medicine and Community Health, University of Minnesota, 717 Delaware St SE, Ste 454, Minneapolis, MN 55414, USA
a r t i c l e
i n f o
a b s t r a c t
Article history:
Received 11 June 2013
Received in revised form 24 September 2013
Accepted 26 September 2013
Available online 9 October 2013
Obesity prevention in children offers a unique window of opportunity to establish healthful
eating and physical activity behaviors to maintain a healthful body weight and avoid the
adverse proximal and distal long-term health consequences of obesity. Given that obesity is the
result of a complex interaction between biological, behavioral, family-based, and community
environmental factors, intervention at multiple levels and across multiple settings is critical for
both short- and long-term effectiveness. The Minnesota NET-Works (Now Everybody Together
for Amazing and Healthful Kids) study is one of four obesity prevention and/or treatment trials
that are part of the Childhood Obesity Prevention and Treatment (COPTR) Consortium. The goal
of the NET-Works study is to evaluate an intervention that integrates home, community,
primary care and neighborhood strategies to promote healthful eating, activity patterns, and
body weight among low income, racially/ethnically diverse preschool-age children. Critical
to the success of this intervention is the creation of linkages among the settings to support
parents in making home environment and parenting behavior changes to foster healthful child
growth. Five hundred racially/ethnically diverse, two–four year old children and their parent or
primary caregiver will be randomized to the multi-component intervention or to a usual care
comparison group for a three-year period. This paper describes the study design, measurement
and intervention protocols, and statistical analysis plan for the NET-Works trial.
© 2013 Elsevier Inc. All rights reserved.
Keywords:
Obesity prevention
Parent
Family
Community
Dietary intake
Physical activity
1. Introduction
Nearly one-third of preschool-age children are overweight
or obese [1]. Racial/ethnic minority and lower socioeconomic
status children are at even greater risk for obesity [2]. The
preschool years provide a unique window of opportunity to
establish healthful eating and physical activity behaviors [3].
Given the complex etiology of childhood obesity, multi-level,
multi-setting interventions are critical for effectiveness [4].
Interventions that directly engage parents and impact the
home environment are needed given that the largest obesity
prevention interventions have been school-based with limited
parental involvement [5–9]. One strategy to more effectively
engage parents in obesity prevention efforts is to consider
the types of organizations and community-based program-
matic initiatives utilized and valued by parents. Integrating
strategies that promote healthy eating and activity patterns
into settings where parents already spend their time could lead
to the development of interventions with high potential for
Contemporary Clinical Trials 36 (2013) 544–554
☆ClinicalTrials.gov Identifier: NCT01606891.
☆☆This study is supported by a grant from the Eunice Kennedy Shriver
National Institute of Child Health and Human Development (U01HD068990).
⁎ Corresponding author at: HealthPartners Institute for Education and
Research, 8170 33rd Ave. S., Mail stop 21111R, Bloomington, MN 55425,
USA. Tel.: +1 952 967 7303.
E-mail address: nancy.e.sherwood@healthpartners.com
(N.E. Sherwood).
1 Tel.: +1 612 626 8594.
2 Tel.: +1 952 967 7303.
3 Tel.: +1 612 626 3693.
1551-7144/$ – see front matter © 2013 Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.cct.2013.09.015
Contents lists available at ScienceDirect
Contemporary Clinical Trials
journal homepage: www.elsevier.com/locate/conclintrial

dissemination and sustainability. Three examples include
public health nurse home-visiting, community-based parent-
ing classes, and pediatric primary care.
Public health nurse home-visiting programs provide
health and psychosocial-related services to at-risk pregnant
women and young mothers [10–15]. National early child-
hood parent education programs also offer home-visiting
models [16,17]. Recently, the nurse home-visiting model was
evaluated for obesity prevention in infants in a randomized
controlled trial [18,19]. The Parents As Teachers Program also
evaluated a parent-targeted home-based intervention to
increase child fruit and vegetable intake [20]. Results suggest
home-visiting holds promise for obesity prevention.
Community parenting classes are also widely available and
appeal to parents of preschool-age children from diverse
backgrounds. Parenting classes promote child school readiness
through building parenting skills and social support networks.
Healthful food choices, active play, and screen time topics
align well with parenting class curriculum and could be readily
incorporated into existing parent-focused community-based
programs.
Primary care is a third important setting through which
parents of preschool-aged children may be reached [21].
Primary care providers are influential sources of health
information who can help parents promote and reinforce
child behaviors related to healthful eating, activity patterns,
and body weight. The primary care setting represents a
unique intervention opportunity for direct, parent-focused
child obesity prevention [21].
In addition to these well-established systems, the neigh-
borhood environment provides resources that can enhance or
detract from parent efforts to support optimal child growth
[22–26]. Without access to these resources, parents face
significant barriers to adopting eating and activity-related
behavioral intervention messages. Thus, obesity prevention
interventions need to identify and connect parents to existing
neighborhood resources.
The goal of the Minnesota NET-Works (Now Everybody
Together for Amazing and Healthful Kids) study is to
integrate home, community, primary care and neighborhood
intervention strategies to prevent obesity among ethnically
diverse preschool-age children. The NET-Works trial is one of
two unique prevention trials that are part of the Childhood
Obesity Prevention and Treatment Research (COPTR) con-
sortium, a National Heart, Lung, and Blood Institute (NHLBI)-
and National Institute of Child Health and Human Develop-
ment (NICHD)-sponsored collaborative effort to develop and
test novel approaches to prevent or treat childhood obesity.
Each field center is testing distinct interventions with unique
populations and eligibility criteria, but share a core set of
common measures and protocols. This paper describes the
NET-Works trial study design, measurement and interven-
tion protocols, and statistical analysis plan.
2. Materials and methods
2.1. Trial design overview
NET-Works is a two-arm, randomized controlled trial to
test the efficacy of a multi-setting, multi-component inter-
vention approach to preventing obesity among racially/
ethnically diverse preschool age children. The NET-Works
intervention includes four main components: 1) a pediatric
primary care brief counseling intervention; 2) a home-based
intervention delivered by NET-Works family connectors to
support parents in making changes in the home environment
and parenting practices to promote healthful eating and
activity patterns; 3) community-based parenting classes
designed to parallel the home-based intervention curriculum
and provide social support to participating parents; and
4) linkages to neighborhood and community resources to
support parents in promoting healthful eating and activity
patterns for their children. Five hundred parent/child dyads
will be randomized to either the NET-Works intervention or a
usual care comparison condition and followed for three
years. Participants will be assessed at baseline and annually.
The primary hypothesis is that children randomized to the
NET-Works intervention will have lower BMI at two and
three years post-randomization relative to usual care com-
parison group children. BMI is the primary outcome across all
four COPTR trials. Recruitment for the trial began in July 2012
and will be completed in December 2013, with the final three
year follow-up data collected in December 2016.
2.2. Study setting and population
The target population for NET-Works is racially/ethnically
diverse preschool children and their parent or primary
caregiver. To reach the intended population, NET-Works has
partnered with 12 primary care clinics and three managed
health care systems that serve diverse populations with
respect to race, ethnicity and income. Over 18 months, 500
families will be recruited, enrolled and randomized to the
intervention or to the usual care comparison group. Admin-
istrative databases and centralized electronic scheduling
systems at the partner clinics provide data needed to target
recruitment efforts on two-to-four year old children residing
in certain zip code areas. The clinics have recent data from
preventive care visits available for calculation of child body
mass index (BMI) percentile to focus recruitment efforts on
children who are potentially BMI-eligible for the study.
2.3. Eligibility criteria and exclusions
Eligibility criteria are assessed on a telephone screening
call and confirmed in person at the first data collection home
visit. A child and his or her parent or primary caregiver are
eligible for the study if: 1) the child is between ages of two
and four years of age; 2) the child has no medical problems
that would preclude study participation as determined by the
primary care physician; 3) does not use any medications that
would affect the child's growth; 4) the child's BMI is greater
than or equal to the 50th percentile according to CDC age and
sex reference standards with no upper limit [27]; 5) the
family's income is below $65,000 per year; 6) the child's
parent agrees to participate in the study and does not plan to
move out of the state in the next three years; 7) the parent or
primary caregiver is willing and able to complete the evaluation
measures and participate in intervention activities if assigned to
the active intervention group; and 8) the parent or primary
caregiver speaks either English or Spanish.
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N.E. Sherwood et al. / Contemporary Clinical Trials 36 (2013) 544–554

2.4. Recruitment
Recruitment procedures are adapted from those used in
our previous pediatric primary care-based obesity prevention
intervention trials. Administrative databases and centralized
electronic scheduling systems at three partner health care
organizations will provide data needed to target families of
two–four year old children whose BMI percentile is at or
above the 50th percentile for age and gender. Clinic liaisons
obtain approval from each child's pediatrician to send a study
invitation letter to the parent or primary caregiver. A list of
physician-approved potentially eligible children is shared
with the NET-Works recruitment team. NET-Works sends the
parent or primary caregiver a study invitation letter from the
pediatrician and researchers. Approximately five working
days later, NET-Works recruitment staff follows up by phone to
provide more information, asks additional screening questions,
and assesses parent/primary caregiver's interest in the study. If
the parent/primary caregiver is interested and the child
appears to be eligible, a home visit for eligibility confirmation,
consent, and data collection is scheduled. The purpose of
this initial home visit is to: 1) explain and discuss the study,
and begin to develop rapport with parents; 2) measure the
index child's height and weight to confirm eligibility; 3) obtain
informed consent; and 4) begin the process of collecting
baseline data. Based on our pilot study experience we antic-
ipate that the majority of the participating parent/caregivers
will be female. We also anticipate recruiting a significant
number of Hispanic families as well as non-Hispanic White,
African American, and multi-race participants.
2.5. Randomization
Prior to the start of recruitment and enrollment, the study
statistician created 6 blocked randomization schedules, one
for each age group (2, 3, 4) by gender (M, F) stratum, that
equally allocated children to the NET-Works intervention or
the usual care comparison group in blocks of 10 to ensure
equivalent study group size. Parent–child dyads will be
randomized to treatment and control conditions after comple-
tion of all baseline measures, including data eligibility require-
ments established by the COPTR consortium. Data eligibility
requirements include valid height and weight measurement, a
minimum of one weekday and one weekend day NDS-R
previous day dietary recall and four days of valid accelerometry
data (see below for details regarding measurements). The
study coordinator will randomly assign the participant to the
condition shown in the next available slot in the stratum-
appropriate pre-defined randomization schedule. The investi-
gators and all assessment staff will remain blinded to experi-
mental assignment until after the final follow-up assessments
are completed.
2.6. NET-Works intervention
The social ecological model provides an overarching
framework for the intervention. The SEM recognizes multiple
levels of influence on a behavior [28]. Fig. 1 illustrates the
multiple levels of influence on child eating and physical activity
behaviors, which influence body weight. The NET-Works inter-
vention reaches into the home and family environment to
influence parent behaviors and attitudes to support changes
in the home that affect food availability, family meals,
television viewing, and active play. Each intervention compo-
nent is situated in community settings where parents and
children already live their lives. The intervention is expected to
be effective in part through taking advantage of the settings
that families already inhabit, and through coordination across
settings to reinforce and link the messages, resources and
feedback families receive about healthful food choices, physical
activity, and body weight for their child. A neighborhood-based
model will be more likely to enhance class participation, reduce
transportation needs/costs, allow the local community re-
sources to be accessed more easily, and foster outside-of-class
interpersonal connections among parents for enhanced social
support.
2.6.1. Intervention components implementation overview
The intervention curricula across each component (home
visiting, parenting classes, neighborhood environment, pediat-
ric primary care) were developed and refined during the pilot
phase of the COPTR consortium. The intervention is imple-
mented by trained research staff including a family connector
who conducts the home visiting and connector check-in calls
and attends the parenting classes, and a parent educator who
conducts the community parenting classes that are based on
the early childhood parenting class model and were developed
in partnership with ECFE in Minneapolis and St. Paul. The home
visiting and parenting classes share a common set of underly-
ing curricula that includes skills building around general
parenting behaviors
and
the
specific
content behaviors
targeted by the intervention (e.g., healthful snacks, family
meals, physical activity). The family connector meets parents
and children in their own home, tailoring the intervention
messages and strategies to best fit with the resources and
motivations of parents. The family connector provides a
one-on-one approach to synergize with the skills and strategies
implemented in a group format in the NET-Works community
parenting classes. Both home visiting and parenting classes
directly connect parents to food and physical activity resources
that already exist in their neighborhood (“community links”).
Primary care providers bolster these messages with parents
during annual well-child visits. Table 1 provides an overview of
the intervention components, including the frequency and
timing of each component and the target behavioral goals and
parenting strategies to support goal achievement.
2.6.2. Home visiting
The goal of the home visiting is to help parents develop
parenting skills, set goals related to child healthful eating,
active play and reduced television viewing, and provide
support for sustaining and building on these behavior and
home environment changes. The dose for the home visiting
intervention component is one visit per month for each of the
three years. The family connector builds a collaborative,
partnership-based goal setting process for parents to facili-
tate child behavior change. Facilitation of the home visits is
modeled on Motivational Interviewing, an approach de-
signed to help individuals explore and resolve ambivalence
about behavior change in a non-confrontational manner.
Home visiting includes a goal setting process guided by the
family connector, healthful action activities to create norms
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N.E. Sherwood et al. / Contemporary Clinical Trials 36 (2013) 544–554

and skills related to the targeted behaviors, and resources for
links in the community to support healthful behaviors.
Family connectors also check in with participants to review
progress on goals and provide support in between home
visits. Family connector check-in contacts can be conducted
over the telephone or via email. Family connectors have
weekly supervision sessions with a licensed mental health
provider with expertise in Motivational Interviewing to
review progress with each participant, problem solve regard-
ing any challenges that arise, and ensure adherence to the
intervention protocol.
2.6.3. Parenting classes
The parenting classes are designed to work synergistically
with the home visiting curriculum. The parenting class and
the home visiting curriculum both include topics that address
parenting skills development, the home food environment,
healthful eating, family meals, television viewing limits,
active play, and goal setting. The parenting class provides a
group format where parents can share their experiences, gain
support from other parents and learn from each other. The
curriculum is research-based and facilitated by a trained
parent educator. The dose for the parenting class component
is 12 classes per year for each of the three years. The
curriculum in years 2 and 3 will build upon and deepen the
topics introduced in year 1, and will address parenting and
developmental issues as children progress from ages 2–
7 years of age. Parent educators also participate in weekly
supervision sessions to ensure adherence to the intervention
protocol.
2.6.4. Neighborhood and community initiatives
The purpose of the neighborhood and community inter-
vention component is to increase access to, and use of,
healthful food, physical activity, and school readiness re-
sources available in the neighborhood communities where
study participants live. Parents are directly linked with
resources in their neighborhood through both the parenting
classes and the family connector home visits. For example,
through the parenting classes, parents take a group field trip
to a local grocery store to practice shopping skills. Commu-
nity initiatives implemented with the family connector
include conducting a walkability assessment of the family's
neighborhood. The family connector reviews neighborhood
food and physical activity resources with the parent at each
home visit, and encourages them to use these resources to
support their home and behavior changes. The community
links include one school readiness community activity (e.g., a
library visit) to promote developmental parenting, sustain
parent interest, and provide active support for whole child
development. Four community links will be included in the
parenting class and home visiting curriculum each year of the
intervention.
2.6.5. Primary care
The primary care provider is an influential connection for
parents. In NET-Works, the primary care provider delivers key
messages around parent behaviors for shaping, reinforcing and
sustaining healthful child eating and physical activity behaviors
and body weight. To support providers in delivering key
messages to parents during well child visits, a brochure was
developed in partnership with the participating clinic systems.
Family Connector
Child
Weight
Status
Active Play 
& Physical 
Activity
Opportunity
Sedentary
Behavior
Physical
Activity
Dietary
Intake
Pediatric 
Primary Care
Clinics
Family Connector
CHILD BEHAVIORS
Family 
meals
Race/
Ethnicity
Daycare/
preschool 
physical
activity
&
food
environment
Parent 
role modeling of
Healthy eating & 
activity
Parent
Support
of child 
activity
Parent offers
of healthy 
food &
beverages
Parental 
feeding 
attitudes
Location & 
# of TVs sets
Home
food & 
beverage
availability
Community 
Parenting
Classes
Home Visiting & 
Connector Check-Ins
Accessibility &
Affordability of
Physical Activity 
And Healthy Food
Neighborhood Context 
Schools
Family Connector
Community Environment
FAMILY ENVIRONMENT
Family Connector
Fig. 1. Socioecological model for obesity prevention.
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N.E. Sherwood et al. / Contemporary Clinical Trials 36 (2013) 544–554

The brochure is used by the primary care provider to converse
about child BMI percentile and strategies parents can use to
promote their child's healthful eating and activity patterns.
The NET-Works family connector will also provide information
about progress on intervention goals to the primary care
provider on an annual basis to reinforce continuity and
integration of intervention messages. The primary care inter-
vention links with the community parenting classes and home
visiting to deliver consistent intervention messages over a
sustained time period.
2.6.6. Intervention component integration
Linkages across the intervention components are created in
several ways with the family connector playing a key role in
this connectivity. Specifically, in addition to conducting home
visits, family connectors facilitate participant entry into
parenting classes and also attend parenting classes. Attending
parenting classes allows the family connector to be knowl-
edgeable about the parenting class content and the experience
their assigned participants are having during class. This
information informs the goal setting that family connectors
and parents work on during home visits. Family connectors
also serve as the liaison between parents and primary care
providers. The home visits and parenting classes also incorpo-
rate connections to community resources for physical activity
and healthy eating as described above.
2.7. Usual care comparison group
The usual care comparison group will receive the primary
care provider component described above, and quarterly
newsletters with information about their child's general
health and wellness and school readiness.
2.8. Participant timeline, assessments, and measures
Data collection takes place in the home setting at baseline,
12, 24, and 36 months by trained and certified, bilingual English
and Spanish research specialists, blinded to experimental
assignment. At 6, 18, and 30 months, a brief telephone survey
is conducted. Participants receive a total of $50 in gift cards for
each set of measurement visits (baseline and each subsequent
annual assessment) and a $5 gift card for each brief telephone
survey. Data collectors are trained by the investigators and, for
COPTR consortium common measures, by the Research Coordi-
nating Unit (RCU) according to standardized protocols. COPTR
uses a train-the-trainer model. “Master Trainers” who partici-
pate in a central training organized by the RCU are responsible
for training and certifying the data collection staff at their field
center. Data collectors must demonstrate high inter- and
intra-rater reliability prior to data collection.
2.8.1. Primary outcome measure — common measure
Body mass index (BMI) is the primary outcome measure
of all four COPTR trials. Body mass index (BMI) is calculated
as weight in kilograms divided by the square of height in
meters. Weight and height are measured with the participant
in light clothing without shoes using the common COPTR
protocol. Weight is measured to the nearest 0.1 kg using
research precision grade, calibrated, digital scales and height
is measured to the nearest 0.1 cm using a free-standing or
wall mounted stadiometer (Seca Corp., Hanover, MD).
2.8.2. Secondary outcomes — common measures
2.8.2.1. Anthropometrics. Waist circumference and triceps
skinfolds are measured for all index children and weight
and height are measured for other children and adults in the
household. Weight and height for adult and child household
members is measured using the above described approach.
Waist is measured to the nearest 0.1 cm just above the
uppermost lateral border of the right ilium using a Gulick II
tape measure, model 67020. The triceps skinfold is measured
to the nearest 0.1 mm using a Lange skinfold caliper. For
quality control, 10% of the anthropometric measurements are
measured by two different data collectors.
2.8.2.2. Dietary assessment. Dietary intake is measured using
24-hour recalls conducted on two weekdays and one weekend
day using NDS-R software. Dietary recalls are collected in-person
or over the telephone in English or Spanish. The Food Amounts
Booklet is used by the respondent to estimate portion sizes.
Recalls are not conducted on consecutive days, do not occur
within a seven day period, and are collected within 30 days. The
Table 1
Overview of intervention components, targets, and parenting strategies.
Intervention
component
Staff person
Frequency
Home visits
Family connector
12 visits per year
Connector check-ins
Family connector
4 phone or email contacts
Parenting classes
Parent educator
A 12 class series each year
Pediatric primary
care
Primary care
provider
Initial well child visit
intervention
Annual well child visit
check-in
Intervention targets across components
Physical activity & active play
Aim for ≥60 min per day
Screen time
Aim for b2 h per day
Sweetened beverages
(including juice)
Aim for b4 oz per day
Portion size
Serve child size portions
Eating out
Aim for eating out once a
week or less
Family meals
Aim for ≥5 per week
Breakfast
Eat breakfast everyday
Fruit and vegetable intake
Aim for ≥5 servings per day
Snacks
Aim for ≤1 treat per day
Parenting strategies promoted across components
Model
Set rules and routines
Be a good example
Nurture
Give attention, praise and
encouragement
Reinforce positive actions
Communicate and respect
each other
Guide
Set limits
Offer choices
Shape
Use rewards and consequences
Find healthy solutions together
Develop healthy habits
Network
Use your community
Ask for help when you need it
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adult responsible for child feeding reports the child's intake.
Quality assurance checks are conducted on at least 10% of the
dietary recalls according to NDS-R standard protocols. Previous
day dietary recalls have been shown to be a valid measure of
dietary intake among children [29].
2.8.2.3. Physical activity. Accelerometry data are collected on
all index children using the GT3X+ monitor. The GT3X+
monitor is worn on the right hip for seven complete days
(including while sleeping and naptime) except during water
activity (e.g., bathing, swimming, showering). The index
parent also wears a GT3X or GT3X+ monitor for seven days
on the right hip. The ActiGraph GT3X+ and the GT3X devices
measure acceleration in three individual orthogonal planes
using a vertical axis, horizontal axis and a perpendicular axis.
The GT3X+ is set to collect data at a 40-Hz frequency and the
GT3X is set to collect data in 1-second epochs. The valid wear
time criteria (minimum) are four days (three weekdays and
one weekend day) of at least 6 h of activity between 5:00 am
and 11:59 pm. Accelerometry has been shown to be feasible
and valid in preschool age children [30–33].
2.8.3. Moderators and mediators
2.8.3.1. Child Eating Behavior Questionnaire (CEBQ). The CEBQ
measures individual differences in child eating behaviors
[34]. The parent reports the child's usual eating behaviors.
The eight subscales are food responsiveness, enjoyment of
food, emotional overeating, desire to drink, satiety respon-
siveness, slowness in eating, emotional undereating, and food
fussiness. The scales have high internal consistency reliability
(range .72–.91) and test–retest reliability (range .52–.87).
The subscales satiety responsiveness, food responsiveness,
and enjoyment of food have been validated in four and five
year old children using behavioral observation measures of
energy intake and eating without hunger [35]. In addition to
these three sub-scales, the food fussiness sub-scale is
completed by parents in NET-Works.
2.8.3.2. Parent feeding styles. Parent feeding styles were
measured using the Parent Feeding Styles Questionnaire [36].
Parents self-report their usual feeding practices in relation to the
target child. The scale consists of 27 items that comprise four
subscales: emotional feeding, instrumental feeding, prompting
to eat, and control over eating. The subscales have high internal
reliability (.65–.85) and test–retest reliability (.76–.83).
2.8.3.3. Family eating patterns. Frequency of family meals and
eating at fast food and other restaurants are also assessed.
Parents report the number of times their family ate breakfast,
lunch, and dinner together during the past seven days [37].
Parents report the number of times the child ate something
at a fast food restaurant during the past week and how many
times the child ate something from another restaurant [38].
Parents are also asked to report how often they choose their
child's meals and snacks each day.
2.8.3.4. Parent support for child PA. Parent support for their
child's physical activity behaviors was measured using four
questions that have been used in previous research and
shown to have good internal consistency (r = .78) and one
week test–retest reliability (r = .81) [39]. Parents report the
frequency with which they provide verbal encouragement to
be active, watch their child play, play with their child, take
them to a location to play or be active.
2.8.3.5. Parenting styles. NET-Works general parenting style
measure is based on a subset of 20 items from a questionnaire
developed from previously published literature on parenting
styles [40]. Previous research identified four parenting styles
that are related to child outcomes (authoritative; authoritari-
an; indulgent/permissive; disengaged/neglectful). Other re-
search has identified two primary parenting dimensions that
relate to child outcomes: warmth/responsiveness; and control.
For NET-Works, items were selected to represent the following
dimensions: nurturance, structure, and behavioral control.
2.8.3.6. Perceived Stress Scale (PSS). The PSS is a widely used
measure of perception of stress designed for use in commu-
nity samples [41,42]. Items tap how predictable, controllable,
and overloaded respondents find their lives. A four-item
short-form of this scale was used, which asks about thoughts
and feelings in the last month and includes items such as
“how often have you felt that you were unable to control the
important things in your life?” Items are rated on a 5-point
Likert scale ranging from 0 (never) to 4 (always). Coefficient
alpha reliability for the PSS in community-based samples is
.85; test–retest reliability is .85.
2.8.3.7. Parenting stress. Parenting stress is measured using
the 4-item scale developed by the Fragile Families and Child
Wellbeing Study [43,44], which includes the following four
statements: “Being a parent is harder than I thought it would
be,” “I feel trapped by my responsibilities as a parent,” “I find
that taking care of my child(ren) is much more work than
pleasure,” and “I often feel tired, worn out, or exhausted from
raising a family.” Items are rated on a 4-point Likert scale
(0 = strongly disagree to 3 = strongly agree). The sum of
the four items serves as the final scale (coefficient alpha
reliability = .63).
2.8.3.8. Neighborhood availability parks/playgrounds and food
stores. To measure neighborhood availability of parks and
playgrounds, parents are asked about the neighborhood
locations that they take their child to for play. The parks and
playgrounds within a one mile radius of the home are
identified using a mapping program (Google Maps). Parents
are asked to report the frequency of visiting each park or
playground with their child during the past month. In addition,
parents are asked to name the most frequent park or
playground they visited during the past month with their
child, and the number of times visited. Parents are asked to
report their most frequent food shopping location and the
distance it is from their home. These measures were developed
for the NET-Works trial.
2.8.3.9. Neighborhood block audit. For NET-Works, a 23-item
modified version of a previously developed block audit
inventory is used [45]. Because the factor structure varied from
sample to sample in previous research, a face-valid method is
used to group items into categories for summary score creation.
Three categories are defined: walkability/support for walking;
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places to go/destinations; physical incivilities. Walkability
includes the following items: sidewalks; pedestrian crossings/
markings; and traffic control signals/stop signs. Places to go
include the following items: nearby parks (size and available
equipment); and commercial outlets. Physical incivilities in-
clude the following items: physical condition of home or
apartment building; visible trash or graffiti; and condition of
buildings. NET-Works focuses on preschool-age children and
therefore items are weighted higher for those that assess
aspects of the neighborhood that are hypothesized to be more
supportive for preschool children's physical activity. For
attractions the weighting scheme keeps yards, parks and other
places on the same scale. For transportation the weighting
scheme keeps sidewalks, traffic and places on the same scale.
2.8.3.10. Home food inventory (HFI). The home food inventory
measure used in NET-Works is based on the previous
research by the investigators and the broader literature on
home food inventories [46,47]. A variety of HFIs have been
published, most of them tailored to the particular dietary
targets in the research question. In our previous research on
the home food environment, the HFI was created by a series
of iterative pilot studies to capture the foods and beverages
targeted by the intervention, in sufficient detail to be both
feasible [time to collect the data; level of detail] and
informative about the amounts of specific foods and bever-
ages in the home. For the present study, the following eight
home food item categories are used: Sugar sweetened
beverages; non-caloric beverages; milk; fruits; vegetables;
fruit/vegetable juices; sweets; packaged snacks. Individual
food items within categories are recorded as either being
present or not present under the appropriate category. Each
HFI is reviewed and edited for accuracy and completeness.
2.8.3.11. Perceived neighborhood environment. Parents are
asked to indicate how much they agree or disagree with a
series of nine statements related to perceptions about traffic
density, road safety, strangers, sporting facilities, and walking
safety in their neighborhood [48].
2.9. Process measures
Process evaluation measures are conducted throughout the
study to assess the integrity of the intervention components
(family connector home visits and check-in contacts, parenting
classes, community link activities, and primary care). Integrity
is described across five domains: (1) fidelity, or message
quality and content; (2) dose delivered, or amount and length
of intervention sessions; (3) dose received, or participant
engagement and satisfaction; (4) reach, or extent to which the
intervention was delivered to and received by the intended
population; and (5) program design (i.e., feasibility and cost
effectiveness). These domains are measured using several
methods including parent surveys, intervention staff docu-
mentation forms, and coding of audio-recorded family con-
nector home visits. Table 2 shows the process evaluation
measures that are collected and described below.
2.9.1. Family connector home visiting and check-in contacts
Before conducting intervention visits and calls, interven-
tion staff are trained and certified in intervention techniques.
Staff attendance, certification, and satisfaction with training
are recorded. After each visit and interaction (i.e., home visit,
phone call), contact length, type and quality of intervention
messages, parent engagement, and parent–staff relationship
are documented by the intervention staff person who worked
with the family. Each home visit is audio recorded, with
participating parent consent, and coded by independent
process evaluation staff for intervention fidelity. At 6-, 18-,
and 30-month time points, parents complete a telephone
survey conducted by independent process evaluation staff
about satisfaction with these intervention components.
2.9.2. Parenting classes and community links
Intervention staff conducting sessions and events docu-
ments attendance, session length and quality, amount of
material covered, and perceived group engagement. After
each session and event, participating parents complete a brief
satisfaction survey. At 6-, 18-, and 30-month follow-up time
points, parents complete a phone-administered satisfaction
survey about these components.
2.9.3. Primary care
Primary care provider trainings are conducted before the
start of the intervention. Provider attendance and satisfaction
with these trainings are recorded. Well-child visit attendance
for comparison and intervention families is measured at the
end of each study year through electronic medical records. At
baseline-, 6-, 12-, 18-, 24-, 30-, and 36-month time points,
parents are asked to report attendance and content and
quality of messages received at the participating child's most
recent well-child visit.
2.10. Statistical analyses
2.10.1. Primary analyses
The primary efficacy analysis will test whether income
racial/ethnic minority of two to four year old children who are
randomized to the NET-Works program have statistically and
clinically lower BMI at 24 and 36 months post-randomization
relative to usual care comparison group children. Data from all
randomized participants will be used to estimate two mixed
models. In each, BMI at either 24 or 36 months will be
predicted from treatment group (NET-Works, usual care)
with age at randomization (2, 3, 4), sex (F, M) and BMI at
baseline included as covariates. The NET-Works study is an
individually randomized group trial, and dependence may be
introduced into the BMI values of NET-Works children whose
parents participate in common parenting classes over the
course of the three-year intervention while there is unlikely to
be dependence in the usual care group where parents are
unlikely to ever interact with each other [49]. Among
NET-Works children randomized to the intervention group,
parenting class cohort will be treated as a random effect, and
the intraclass correlation of BMI among children within cohorts
will be estimated. Each usual care child will be treated as a
random effect and BMI assumed independent. It will be
concluded that NET-Works was efficacious if the fixed
treatment group parameter in both mixed models is statisti-
cally significant and BMI is meaningfully lower (Cohen's
d ≥.30) among NET-Works children.
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These analyses will be conducted using multiply imputed
datasets. A fully conditional specification approach will be used
for the imputation process, and will include in the imputation
model all variables included in the primary analytic (scientific)
model as well as interactions among them to improve the
precision of the imputations. All covariates in the primary
analysis will have been measured at baseline prior to
randomization and are therefore available for observed and
unobserved BMI values. The random effects estimated in the
primary analytic model will also be estimated in the imputa-
tion model [50]. The mechanisms that are likely to produce
missing observations in the analytic dataset should result in
Table 2
NET-Works process evaluation.
Fidelity. The extent to which the intervention is delivered as intended; quality of the intervention; how well an intervention is being implemented compared
to its original design; could include, but not limited to, content & quality of messages, adherence to protocol, and intervention staff skill/training/certification.
Intervention component
Construct(s)
Data collection method
Completed by
Timing of data collection
Primary care
Content of messages received
Adherence survey
Parent
Baseline, 6, 12, 18, 24,
30 and 36 months
Provider training attendance and
satisfaction
Survey
Pediatric primary care
providers
After provider training
Home visits and
check-in calls
Content and quality of messages
delivered/received
Staff training attendance,
certification and satisfaction
Documentation forms
Intervention staff
After every visit/call
Satisfaction survey
Parent
6, 18, and 30 months
Survey
Intervention staff
After staff training
Parent class sessions and
community events
Content and quality of messages
delivered/received
Staff training attendance,
certification and satisfaction
Documentation form
Intervention staff
After every class/event
Satisfaction survey
Parent
After every class/event
and 6, 18, and 30 months
Survey
Intervention staff
After staff training
Dose delivered. The amount of intervention that was delivered; could include, but not limited to, number and length of sessions implemented.
Intervention component
Construct(s)
Data collection method
Completed by
Timing of data collection
Well-child visit
Attendance
Electronic medical records
Process evaluation staff
Annually
Home visits and
check-in calls
Activities completed, messages/
materials delivered, attendance
Documentation forms
Intervention staff
After every visit/call
Parent class sessions and
community events
Activities completed, messages/
materials delivered, attendance
Documentation form
Intervention staff
After every class/event
Dose received. The amount of intervention that was received; could include, but not limited to, participant engagement, and intervention messages
or materials received.
Intervention component
Construct(s)
Data collection method
Completed by
Timing of data collection
Well-child visit
Messages/material received
Adherence survey
Parent
Baseline, 6, 12, 18, 24, 30
and 36 months
Home visits and
check-in calls
Engagement
Satisfaction survey
Parent
6, 18, and 3 months
Documentation forms
Intervention staff
After every visit/call
Parent class sessions and
community events
Engagement
Satisfaction survey
Parent
After every class/event
Documentation form
Intervention staff
After every class/event
Program design. The assessment of non-specific treatment effects, could include, but not limited to participant satisfaction with, feasibility, and costs
of intervention.
Intervention component
Construct(s)
Data collection method
Completed by
Timing of data collection
Well-child visit
Participant satisfaction
Adherence survey
Parent
Baseline, 6, 12, 18, 24, 30
and 36 months
Home visits and
check-in calls
Participant satisfaction
Satisfaction survey
Parent
6-, 18-, and 30-month surveys
Staff time to prepare and travel
for delivery of intervention
Documentation forms
Intervention staff
Quarterly
Parent class sessions and
community events
Participant satisfaction
Satisfaction survey
Parent
After every class/event and
6-, 18-, and 30-month surveys
Staff time to prepare and travel
for delivery of intervention
Documentation forms
Intervention staff
Quarterly
Reach. The proportion of intended recipients who actually participate in an intervention; the extent to which the intervention is reaching the target
population; could include, but not limited to, attendance, participation, and engagement by group (e.g. race, gender, SES, intervention group).
Intervention component
Construct(s)
Data collection method
Completed by
Timing of data collection
Well-child visit
Attendance, participation, and
engagement by clinic, race, ethnicity
Similar to above measures, but examined by groups noted in previous column
Home visits and
check-in calls
Attendance, participation, and
engagement by race, ethnicity
Similar to above measures, but examined by groups noted in previous column
Parent class sessions and
community events
Attendance, participation, and
engagement by location, race, ethnicity
Similar to above measures, but examined by groups noted in previous column
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missing observations that are missing at random (MAR; e.g.,
early dropouts, busy schedule) or possibly missing not at
random (MNAR; e.g., sporadic missing). The primary analytic
models will be estimated from imputed datasets that assume
all missing observations to be MAR. Sensitivity analyses will
assess the severity of non-random missingness that would be
necessary to reconsider the conclusions drawn from the
primary analysis.
2.10.2. Detectable difference, sample size and power
A power analysis determined the minimum detectable
standardized effect size (MDSE, Cohen's d) in BMI for
NET-Works versus usual care children at 24 or 36 months
post-randomization (i.e., the fixed treatment group parameter).
The effective number of follow-up BMI observations was
estimated separately for each treatment group by imposing
assumptions about the design effect resulting from NET-Works
parent–child dyads clustered within parenting class cohorts
(ICCPC = .01–.03 NET-Works, ICCPC = .00 usual care), the
design effect resulting from autocorrelation within cohorts
(rPC = .30–.50 NET-Works, rPC = .00 usual care) and children
(rchild = .40–.60) between baseline and follow-up BMI, and
the proportion of children from whom BMI will be available
(75–85%) (Table 3).
NET-Works dyads will be clustered within about 16
parenting class cohorts (M = 15.6 dyads/cohort). The clus-
tered sample size in each treatment group (n = 250) was
divided by the design effect introduced by clustering within
parenting classes, DEFFPC = [1 + (n −1)ρ], to estimate the
effective number of independent dyads in each group. Next,
the effective number of independent dyads was divided by
the design effect introduced by cohort and child autocorre-
lation in BMI, DEFFcorr = (1 −r2), to adjust for the efficiency
gain resulting from controlling for baseline BMI. In this case,
r = [nρ/(1 + (n −1)ρ)]ρc + [(1 −ρ)/(1 + (n −1)ρ)]ρs,
where n is the average number of dyads per cluster; ρ is the
correlation in BMI values of different children in the same cluster
at a single point in time, ICCPC; ρc is the cohort auto-correlation
in BMI values, rPC; and ρs is the child auto-correlation in BMI
values, rchild [51,52]. Finally, the NET-Works and usual care
sample sizes were reduced to 75–85% of their estimated
values to account for the expected number of children with a
follow-up BMI. We will use a generalized Holm procedure to
ensure a family-wise Type I error rate of .05 in the two mixed
models, so that the treatment group parameter with the smaller
p-value will be tested at α2 = .025, while the treatment group
parameter with the larger p-value will be tested at α2 = .05
[53,54].
The resulting MDSEs are displayed in Table 2. Given
median values for ICC and retention assumptions (ICCPC =
.02, 80% follow-up) and conservative alpha and autocorrela-
tion assumptions (α2 = .025, rPC = .30, rchild = .40), the
MDSE is d = .305. When α2 = .05, the comparable MDSE is
d = .277. These effect sizes are in keeping with our stated
goal of detecting a clinically meaningful difference (d = .30)
in BMI between treatment groups at 24 and 36 months.
A similar approach will be utilized for the analysis of
secondary endpoints.
2.11. Data monitoring and participant safety
Adverse events will be assessed systematically at each data
collection visit with direct queries for all injuries, illnesses or
other medical problems requiring a visit to a medical care
provider and related to participation in the study. Serious
Adverse Events (SAEs) are specifically monitored. Adverse
events will also be recorded and evaluated when they come to
the attention of study staff between the data collection visits.
An independent Data & Safety Monitoring Board has been
selected and reports to NIH to review study protocols and
provide oversight of recruitment and study progress, data
quality and completeness, and participant safety.
3. Discussion
This paper describes the study design, measurement and
intervention protocols, and statistical analysis plan for the
Minnesota NET-Works trial, one of the four multi-setting,
multi-component childhood obesity interventions that are part
of the seven-year COPTR consortium. Five hundred racially/
ethnically diverse two–four year old children and their parent
will be randomized to the multi-component NET-Works
intervention or to a usual care control group for a three year
period. The NET-Works study offers a unique opportunity to
synergistically combine several single-setting interventions
that have been implemented and evaluated in previous studies
into a multi-component, multi-setting comprehensive inte-
grated intervention. The intervention components include
home visits, community parenting classes, community links,
and primary care provider intervention. The coordination of
the intervention components is facilitated by the family
connector. These components will be linked with each other
and with the family home environment, allowing families to
receive consistent and multi-sourced messages and support for
the targeted behavior and environment changes. The inter-
vention is expected to be feasible and effective partly through
taking advantage of the settings that families already inhabit,
and through incorporating coordination across settings to
reinforce and link the messages, resources and feedback
families receive about healthful food choices, physical activity
and body weight for their child.
Strengths of the NET-Works trial include the focus on
preschool-age children at risk for obesity and their parents, a
comprehensive evaluation protocol, the 3 year length of
follow-up, and the multi-component, integrated interven-
tion. The evaluation protocol includes measures of dietary
intake, physical activity, the household food environment,
the neighborhood environment, general and domain-specific
parenting strategies, as well as measures of child cognitive
development and novel measures of stress (i.e., hair cortisol).
The comprehensive evaluation protocol will allow the impact
Table 3
Minimum detectable effect size, d, when α2 = .025, ICCPC = .01–.03,
rchild = .40,
rPC = .30,
and
75–85%
of
randomized
children
provide
follow-up BMI data.
ICCPC
Follow-up BMI data
85%
80%
75%
.01
.286
.294
.304
.02
.296
.305
.315
.03
.307
.316
.326
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of the intervention to be evaluated on a wide range of
outcomes, in addition to the primary focus on child BMI.
Additionally, key moderators and mediators of the interven-
tion will be explored. The NET-Works study includes detailed
process evaluation measures developed in collaboration with
the other COPTR sites. The process evaluation data will allow
for examination of intervention fidelity, dose, and reach and
the relationship between specific intervention components
and study outcomes. The integration of the intervention
components into existing and trusted settings where parents
and children already spend time may increase the likelihood
that if successful, the NET-Works intervention can be
sustained and adopted widely within existing community
parenting education and home visiting programs that include
a national reach.
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Net-WORKS Study CONSORT Diagram 
 
 
ENROLLMENT
YEAR 1 FOLLOW-UP
ANALYSIS 
ALLOCATION
Screened (n = 2463) 
Randomized (n = 534) 
Control (n = 269) 
Intervention (n = 265) 
 
Retained (n = 261, 97.0%) 
Lost to Year 1 follow-up (n=8)  
• 
Unable to schedule/contact (n=3)  
• 
Moved (n=3) 
• 
Decline/refused height/weight (n=1) 
• 
Investigator withdrawal (n=1) 
Analyzed (n = 269) 
Analyzed (n = 265) 
Excluded (n = 1929) 
• 
Not meeting inclusion criteria (n = 640) 
• 
Declined to participate (n = 1041) 
• 
Unable to schedule or contact (n = 1) 
• 
Incomplete baseline data (n = 77) 
• 
PI withdrawal = (n = 170) 
Retained (n = 242, 91.3%) 
Lost to Year 1 follow-up (n=23)  
• 
Unable to schedule/contact (n=10)  
• 
Moved (n=5) 
• 
Decline/refused height/weight (n=8) 
• 
Investigator withdrawal (n=0) 
YEAR 2 FOLLOW-UP
Retained (n = 257, 95.5%) 
Lost to Year 2 follow-up (n=12)  
• 
Unable to schedule/contact (n=7)  
• 
Moved (n=2) 
• 
Decline/refused height/weight (n=2) 
• 
Investigator withdrawal (n=1) 
Retained (n = 226, 85.3%) 
Lost to Year 2 follow-up (n=39)  
• 
Unable to schedule/contact (n=13)  
• 
Moved (n=10) 
• 
Decline/refused height/weight (n=15) 
• 
Investigator withdrawal (n=1) 
YEAR 3 FOLLOW-UP
Retained (n = 258, 95.9%) 
Lost to Year 3 follow-up (n=11)  
• 
Unable to schedule/contact (n=2)  
• 
Moved (n=7) 
• 
Decline/refused height/weight (n=1) 
• 
Investigator withdrawal (n=1) 
Retained (n = 235, 88.7%) 
Lost to Year 3 follow-up (n=30)  
• 
Unable to schedule/contact (n=2)  
• 
Moved (n=9) 
• 
Decline/refused height/weight (n=18) 
• 
Investigator withdrawal (n=1)