J Autism Dev Disord
DOI 10.1007/s10803-017-3354-3
ORIGINAL PAPER
Time-Lag Between Diagnosis of Autism Spectrum Disorder
and Onset of Publicly-Funded Early Intensive Behavioral
Intervention: Do Race–Ethnicity and Neighborhood Matter?
Marissa E. Yingling1 · Robert M. Hock2 · Bethany A. Bell2
© Springer Science+Business Media, LLC 2017
Abstract Health coverage of early intensive behavioral
intervention (EIBI) for children with autism spectrum disorder (ASD) is rapidly expanding across the United States.
Yet we know little about the time-lag between diagnosis
and treatment onset. We integrated administrative, Medicaid
claims, and Census data for children in an EIBI Medicaid
waiver (n = 473) to examine the relationship between timelag and (a) child race–ethnicity and (b) neighborhood racial
composition, poverty, aluence, and urbanicity. We explored
whether the relationship between child race–ethnicity and
time-lag varies by neighborhood characteristics. Average
time-lag between diagnosis and treatment onset was nearly
3 years. Child race–ethnicity and neighborhood characteristics did not predict time-lag. Reducing time-lag is critical to
ensuring that children with ASD receive treatment as early
as possible.
Keywords Autism spectrum disorder · Early intensive
behavioral intervention · Medicaid · Time-lag · Disparities
Introduction
To address the needs of the 1 in 68 children in the United
States who meet criteria for autism spectrum disorder (ASD)
(Centers for Disease Control and Prevention 2014), health
coverage of early intensive behavioral intervention (EIBI) is
* Marissa E. Yingling
marissa.yingling@louisville.edu
1
Kent School of Social Work, University of Louisville, 2217
S 3rd St., Julius John Oppenheimer Hall, Louisville, USA
2
College of Social Work, Hamilton College, University
of South Carolina, 1512 Pendleton Street, Columbia, USA
rapidly expanding. Three critical developments are underway. First, 44 states, the District of Columbia, and the U.S.
Virgin Islands each have health insurance mandates requiring coverage of EIBI, and there are ongoing eforts to pass
mandates in remaining states (Autism Speaks 2016). Second, in an efort to prevent duplication of services, states
who adopted EIBI via 1915(c) Home and Community-Based
Services (HCBS) Medicaid waivers (e.g., South Carolina
Department of Disabilities and Special Needs 2007) are
required by the Centers for Medicare and Medicaid Services
to transition the service to Medicaid state plans (Centers for
Medicare and Medicaid Services 2014). Finally, 29 states
and the District of Columbia require that individual and
small business health plans cover behavioral intervention
based on the principles of applied behavior analysis (ABA)
under their ten “essential health beneits” (Autism Speaks
2014).
Despite these changes in healthcare policy and service
provision, the Interagency Autism Coordinating Committee (2013) cites disparities in access to early intervention
services as among the most pressing yet understudied areas
of research on ASD. Similarly, the World Health Organization (World Health Organization 2013) highlights the need
for research that focuses on inequitable access to services
for children with ASD, as well as the challenges of implementing large-scale, community-based early intervention.
Indeed, although states are expanding health coverage of
EIBI, research on access to this service is lacking. Evidence
suggests that children with ASD experience disparities in
access to a range of services (Liptak et al. 2008; Magaña
et al. 2012; Murphy and Ruble 2012; Parish et al. 2012;
Shattuck et al. 2009; Siller et al. 2014; Tregnago and CheakZamora 2012). Yet states are providing EIBI with minimal
research to guide equitable service delivery. The swell in
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J Autism Dev Disord
the number of children eligible to receive EIBI is outpacing
research that could inform policy and practice.
Importance of Early Diagnosis and Treatment Onset
Although families use a variety of services to treat ASD
(Green et al. 2006; Thomas et al. 2006), EIBI is a wellestablished, evidence-based treatment (Howlin et al. 2009;
Lovaas 1987; National Autism Center 2015; Reichow et al.
2014). It involves the application of ABA procedures in oneon-one instruction of adaptive and functional skills (e.g.,
communication, cognitive skills) in young children (Klintwall and Eikeseth 2014), and it is the most preferred and
frequently used treatment approach among parents surveyed
in prior research (Stahmer et al. 2005; Thomas et al. 2006).
Meta-analyses of EIBI indicate that children make signiicant improvements in intellectual ability, language, social
communication, and daily living skills (Peters-Scheffer
et al. 2011; Virués-Ortega 2010), and evidence suggests
that the younger children are upon treatment entry, the more
likely they are to improve on key outcomes (Granpeesheh
et al. 2009; Makrygianni and Reed 2010; Perry et al. 2011;
Virués-Ortega et al. 2013). For example, unprecedented
research on children enrolled in a province-wide program
in Ontario, Canada revealed that compared to children who
began EIBI at 4 years old or older, children who began EIBI
younger than 4 years old completed the program with better
outcomes on most measures (Perry et al. 2011).
Currently, the dominant focus of research on access to
services is the age at which children receive a diagnosis of
ASD and the predictors of age of diagnosis. In recent years,
evidence of delays and disparities in diagnosis prompted
state- and nation-wide initiatives to screen and evaluate children earlier, and there are ongoing developments to improve
and expand these eforts (Peacock and Lin 2012). This line
of research is critical and well justiied; the sooner children
receive a diagnosis, the sooner they can enter treatment. Yet
there exists an underlying assumption that after receiving
a diagnosis, children immediately access treatment. To the
contrary, parents report that post-diagnosis, they are unsure
of where to turn or what steps to take. In a study that highlighted parents’ experiences after diagnosis, parents reported
feeling “abandoned by the community… like trying to run
through a maze blind folded” (Moodie-Dyer et al. 2014,
p. 355).
In the post-diagnosis period, parents enter an unknown
and complex reality. In addition to uncertainty, they face
years-long waitlists (L & M Policy Research, LLC 2014), a
shortage of providers (Wise et al. 2010), and other factors
that act as barriers to treatment utilization, such as competing time demands of school (Yingling et al. 2017). Given
the importance of enrolling children in treatment as early
as possible, developing an understanding of how children
13
proceed from diagnosis to treatment onset as well as factors associated with this time-lag is imperative. In particular,
research suggests that child race–ethnicity and neighborhood
characteristics are factors to consider.
Race–Ethnicity and Time to Treatment Onset
Current literature suggests that black and Latino children
with ASD may be less likely to receive timely treatment.
In what appears to be the only study in which the impact of
race on time-lag to treatment is explored, researchers demonstrated that African American children may be at a disadvantage (Burkett et al. 2015). When asked to explain delays
in diagnosis and treatment initiation among African American children, family members cited distrust of healthcare
providers as well as a lack of information about ASD and
the resources available to them (Burkett et al. 2015). These
results add to a larger body of literature on race–ethnicity
and children’s mental health treatment, in which African
American parents report more negative help-seeking attitudes (i.e., acknowledgement of the existence of psychological problems and propensity to seek assistance from a professional) and greater mental health stigma than European
Americans or Hispanic Americans (Turner 2009), and more
negative expectations of treatment outcomes than Caucasian parents (Bussing et al. 2003). Among African American
mothers living in rural areas, Murry et al. (2011) found that
although they were conident that mental health professionals could help their children, the mothers preferred to seek
support from family, church, and schools. They also cited
community stigma and cultural distrust as barriers. Further,
in a study on predictors of EI evaluation and enrollment,
children with mothers who identiied as black and reported
higher poverty levels were less likely to receive an evaluation and to enroll in services (Clements et al. 2008).
To date, Magaña et al. (2013) are the only researchers
to examine the role of ethnicity at the individual level on
enrollment in a Medicaid-funded EIBI program. In Wisconsin’s program, they documented that despite reporting more
unmet needs, parents of Latino children with ASD were less
likely to enroll. This aligns with available literature on Part
C Early Intervention (EI) services. For example, in a study
that investigated diferences in parents’ experiences with
the pediatric referral process to EI services, parents with
lower health literacy, or “the degree to which individuals
can obtain, process, and understand the basic health information and services they need to make appropriate health
decisions” (Selden et al. 2000), experienced greater diiculty contacting EI providers and were confused about the
referral process, including written materials provided to
them by pediatricians (Jimenez et al. 2013). Limited health
literacy, particularly in the twenty-irst century when the
internet is a primary source of information for ASD services,
J Autism Dev Disord
disproportionately impacts parents who identify with a
minority race and who report limited English proiciency
and lower educational attainment (Knapp et al. 2011). In
sum, extant literature on race–ethnicity and access to services among children with ASD highlights the importance of
examining the role of race–ethnicity in the time-lag between
diagnosis and treatment onset.
Neighborhood Characteristics and Time to Treatment
Onset
A child’s neighborhood may also impact timely treatment
onset. There is substantial, longstanding evidence that characteristics of an individual’s residence afect healthcare
access (e.g., racially/ethnically segregated neighborhoods
and neighborhoods with high concentrations of poverty).
At the turn of the twenty-irst century, Williams and Collins
(2001) argued that racial residential segregation, commonly
associated with concentrated poverty, is a fundamental cause
of healthcare disparities. Although additional research is
needed to target speciic underlying causes of healthcare
disparities within racially/ethnically segregated neighborhoods, literature published in the past 15 years underscores
their argument (White et al. 2012). Indeed, research points to
an association between neighborhoods with socioeconomic
disadvantage and poor access to healthcare generally, a relationship that persists after controlling for individual-level
characteristics (Kirby and Kaneda 2005). Neighborhoods
marked by socioeconomic disadvantage may experience
challenges such as recruiting providers to serve the area
(Auchincloss et al. 2001; Kim et al. 2009). Notably, racial
and ethnic minorities are more likely to live in neighborhoods with high poverty rates. On average, white children
live in neighborhoods with a poverty rate of 7%, whereas
black and Latino children live in neighborhoods with poverty rates of 21% and 19%, respectively. As Acevedo-Garcia
et al. (2008) assert, the “worst-of white children are better
of than the majority of black and Hispanic children, and
these disparities are not accounted for by diferences in family poverty” (p. 324). White children rarely experience double jeopardy, whereby children live in poor families and in
poor neighborhoods.
A study by Shattuck et al. (2009) is the only one to date
on the relationship between neighborhood characteristics
and access to EIBI. Using administrative data of Wisconsin’s Medicaid-funded EIBI program, researchers found that
children who lived in census tracts with a higher percentage of families with incomes ≥ 200% of the federal poverty
level, a higher percentage of women 25 and older with at
least a high school degree, and a higher percentage of people
who were white were more likely to enroll. These results are
similar to those in related areas of research. In a study on
timeliness of provider designation in New York City’s EI
program, children who lived in low-income neighborhoods
and neighborhoods with large Spanish-speaking populations
experienced delays (Kim et al. 2009). Researchers cited the
shortage of providers in the state, both monolingual and
bilingual, as well as providers who perceive low-income
neighborhoods as less desirable work environments, as possible explanations for observed delays. Likewise, children
who lived in socially disadvantaged neighborhoods were
at increased risk of never receiving EI services (McManus
et al. 2013).
In addition to racial residential segregation and neighborhood poverty, individuals who reside in rural areas experience numerous barriers to healthcare, including provider
shortages, higher healthcare costs, and geographic isolation,
which translates to increased travel time and transportation
costs (Florence et al. 2012). This appears to be the case
among children with ASD. For example, Murphy and Ruble
(2012) found that parents who lived in non-metropolitan
counties in Kentucky were more likely to report diiculties accessing professionals trained in the treatment of ASD
compared to parents who lived in metropolitan counties in
Kentucky. Importantly, although rural populations are overwhelmingly white, the number of racial and ethnic minorities who live in rural areas grew 21.3% between 2000 and
2010 (Johnson 2012). This trend suggests that it is more
important than ever to examine whether the relationship
between race–ethnicity and access to treatment varies by
neighborhood urbanicity.
Behavioral Model of Health Services Use
In response to a lack of research on access to EIBI, it is
paramount that researchers attend to the labyrinthine system
parents navigate to access treatment for their children. Central to this efort is the recognition that the term “access,”
which is commonly plagued by ambiguity and used diferently across studies, is a multidimensional construct. To
make progress, it is essential that researchers move beyond
the dichotomization of access (e.g., yes/no), and instead
identify and more precisely measure multiple indicators of
access over time. Andersen’s Behavioral Model of Health
Services Use (BMHSU; Andersen et al. 2013), a well-established model commonly used in health services research,
ofers a solid foundation for this work. Originally published
in 1968, six subsequent revisions relect decades of advancements in health services literature. Broadly, the authors
deine access as “actual use of personal health services and
everything that facilitates or impedes their use” and “the
link” between health services and people who receive the
“right services at the right time to promote health outcomes”
(2013, pp. 33–34). The goals inherent in the model include
the prediction of service use, promotion of social justice,
and enhancement of the effectiveness and efficiency of
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J Autism Dev Disord
service provision. In addition to these goals, we selected this
model because of its multiple dimensions of access, lexible
application to a range of health services, inclusion of both
individual and contextual factors, and bidirectional relationship between four domains (i.e., individual characteristics,
contextual characteristics, health behaviors, and outcomes).
Furthermore, literature on the BMHSU provides insight into
explanations for and solutions to disparities in access.
The BMHSU includes individual and contextual predisposing, enabling, and need characteristics. In the current
study, we focus on child race–ethnicity and neighborhood
characteristics (i.e., individual and contextual predisposing
social characteristics, respectively), and two of the model’s
six dimensions of access, or realized access (i.e., utilization)
and inequitable access (i.e., access due to social structure
variables, such as race–ethnicity). We identify factors that
contribute to the timely onset of EIBI (i.e., utilization of
initial therapy session). In particular, we examine the impact
of a child’s race–ethnicity and neighborhood racial composition, poverty, aluence, and urbanicity to determine if there
is inequitable access to EIBI. For the purpose of this study,
we deine realized access as the timely onset of EIBI postdiagnosis. Because all children in the study participated in
an initial therapy session, all children realized access. Yet
there is greater nuance to realized access than whether or not
a child participated in an initial therapy session. More specifically, given the emphasis placed on age of treatment onset,
we focus on the time-lag (i.e., number of days) between
diagnosis and realized access (i.e., initial therapy session).
If results suggest a relationship between child race–ethnicity
and time-lag and/or neighborhood characteristics and timelag, then there is evidence of inequitable access.
Based on existing literature, the research questions guiding this study include: What is the relationship between
time-lag and (a) child race–ethnicity and (b) neighborhood
poverty, aluence, racial composition, and urbanicity? Does
the relationship between time-lag and child race–ethnicity
difer by neighborhood racial composition, poverty, aluence, and/or urbanicity? Figure 1 depicts the relationships
examined.
Methods
In 2007, South Carolina became one of the irst states in
the country to ofer a 1915(c) HCBS Medicaid waiver speciically for the statewide provision of EIBI. For 10 years,
the South Carolina Pervasive Developmental Disorder (SC
PDD) Program provided up to 3 years of EIBI to children
between the ages of three and ten who received a diagnosis
of ASD made by a professional psychologist by age eight.
Based on need, each child received a maximum of $50,000
per year and up to 40 h of direct line therapy per week, of
13
Fig. 1 Empirical model of study aims
which at least 50% must have taken place inside the child’s
home (South Carolina Department of Disabilities and Special Needs 2013). We partnered with the South Carolina
Department of Disabilities and Special Needs (SC DDSN)
to create a comprehensive dataset (N = 2338) of all children
with ASD who enrolled in the SC PDD Program between
the date that the irst child enrolled (February 6, 2007) and
the end of the irst quarter of calendar year 2015 (March
31, 2015).
To conduct the current study, we irst combined paper
case records, electronic spreadsheets, and electronic records
from SC DDSN’s Consumer Data Support System (CDSS)
to build a base dataset. We then sent the dataset to the South
Carolina Revenue and Fiscal Afairs Oice (RFA) to obtain
Medicaid claims data and Census data. The RFA returned
the base dataset with all identiiers removed along with a
dataset that included census-tract data and a dataset that
included Medicaid claims data. After data integration, we
included children in the study sample if they were diagnosed
after SC DDSN established a waitlist to meet the growing
demand for the program (August, 2007) and had dates of
diagnosis, placement on waitlist, enrollment, assessment,
and initial therapy session (n = 473). For families that had
two siblings with ASD in the program, we randomly selected
one of the children. This reduced the dataset by 50 children. Details on missing data are below. We received institutional review board approval from the University of South
Carolina.
Measures
Time‑Lag
A child proceeds through several distinct stages to begin
participating in the SC PDD Program. After receiving a
J Autism Dev Disord
diagnosis, a parent or service coordinator requests that the
child’s name be placed on the program waitlist. When a slot
in the program is available and the child is at the top of
the waitlist, SC DDSN oicially enrolls the child. Parents
select a provider from a list of providers that serve their residential area, and then schedule an intake assessment. After
an assessment, the parent and provider schedule the irst
therapy session, and the child begins therapy on a mutually
agreeable date. The intake assessment and the irst therapy
session can take place either inside the home or in a treatment center. In the current study, we calculate time‑lag as
the number of days between these distinct stages. As illustrated in Fig. 2, we use four measures of time-lag. These
include Date of Diagnosis to Date on Waitlist (Time 1),
Date of Enrollment to Date of Assessment (Time 2), Date
of Assessment to Date of Initial Therapy Session (Time 3),
and Date of Diagnosis to Date of Initial Therapy Session
(Time 4). RFA provided children’s date of diagnosis, and
SC DDSN provided children’s waitlist, enrollment, assessment, and initial therapy dates. The time-lag between placement on waitlist and enrollment is not included because it
is administrative in nature and due to funding allocated by
the state legislature.
Primary Independent Variables
We combined data from SC DDSN and RFA to create the
primary variable child race–ethnicity (non-Hispanic white,
non-Hispanic black, Hispanic, non-Hispanic other, and
unknown). Both sources provided the category unknown,
and we derived non‑Hispanic other from a range of categories in the original data otherwise too small to analyze (i.e.,
Asian, Hawaiian/Paciic Islander, and American Indian). We
obtained neighborhood variables through RFA, whereby
personnel assigned a census tract ID to children based on
the residential address recorded in SC DDSN’s CDSS.
Racial composition is the percent of white residents in the
census tract (grand-mean centered). Neighborhood poverty
is a composite variable calculated as a z-score computed
from the percent of the following variables commonly used
to measure neighborhood poverty (Leventhal and BrooksGunn 2003), or (a) single parent female headed households,
(b) percent of people below the federal poverty level, (c)
residents who receive cash assistance, (d) residents enrolled
in SNAP, (e) residents who receive SSI, and (f) people who
are unemployed. Also a composite measure, neighborhood
aluence, which is commonly used to measure neighborhood
quality, is a z-score computed from the following variables
often used to measure neighborhood aluence (Leventhal
and Brooks-Gunn 2003) the median household income,
percent of residents with professional/managerial employment, and percent of residents with a Bachelor’s degree or
higher. We calculated the poverty and aluence composite variables by taking the average of the z-scores for each
of the indicators listed above for each composite variable.
To measure urbanicity, we used Rural–Urban Commuting
Areas (RUCA) to create dummy variables for urban, suburban, and rural census tracts. RUCA codes are at the level of
census tracts and are described by the United States Department of Agriculture as codes that use “measures of population density, urbanization, and daily commuting” (United
States Department of Agriculture 2016). The most recent
RUCA codes are used in this study and are based on the
2010 decennial census and the 2006–2010 American Community Survey.
Covariates
Covariates collected from SC DDSN include adaptive
behavior (Adaptive Behavior Composite [ABC]) standard
score on the Vineland-II (grand mean centered), which is a
standardized measure of adaptive behavior based on communication, daily living skills, and socialization (Sparrow et al.
2005), sex (1 = female, 0 = male), single parent household
(1 = yes, 0 = no), children in household (1 = 3 or more children, 0 = 2 or fewer children), and sibling with ASD (1 = yes,
0 = no). Covariates collected from the RFA included Asper‑
ger’s (1 = yes, 0 = no), Intellectual Disability (1 = yes,
0 = no), and age of diagnosis (measured in months, grand
mean centered). Family socioeconomic status is measured by
Fig. 2 Process model of timelag in the SC PDD program
13
J Autism Dev Disord
the payment category billed by SC PDD program providers,
which is most often determined by family income. Sources
included payment under the Tax Equity and Fiscal Responsibility Act (TEFRA), which assists families with incomes
too high to qualify for Medicaid, Supplemental Security
Income (SSI), which assists low-income families, or other
payment source (e.g., inpatient psychiatric facility). We used
data from both SC DDSN and RFA to create the variable age
of enrollment (measured in months, grand mean centered).
Missing Data
Of the 802 children who met inclusion criteria, 486 children
had no missing data. On average, children were missing two
items. There was no missing data on child race–ethnicity.
Although children with a census tract ID were not missing
on any neighborhood variables, 37 children did not have a
census tract ID. Variables with strong correlations included
Asperger’s, Intellectual Disability, age of diagnosis, age
of enrollment, adaptive behavior, single parent, children
in household, and sibling with ASD. These correlations
indicate that missingness is not missing completely at random, and caution is necessary when interpreting results that
involve these variables. However, missing data across all
children and all variables was 8.3%. When missing data is
less than 10%, listwise deletion does not cause any more
bias than imputation (Basilevsky et al. 1985; Roth 1994).
Therefore, we chose to listwise delete. The remaining 486
children included children (n = 13) with negative outcome
values. Because these values were impossible and most
likely attributable to data entry error, we excluded them from
the study for a inal sample size of 473.
Statistical Analyses
We conducted all analyses using SAS® 9.4. Initially, we
intended to use two-level organizational models to answer
our research questions (i.e., children nested in census tracts).
However, due to the number (n = 258) of singletons (i.e.,
one child in one census tract), the models did not converge.
Therefore, we estimated a total of 20 ordinary least squares
(OLS) contextual regression models using PROC REG, an
appropriate approach when the interest is in the context of
the neighborhood rather than diferences between neighborhoods (Diez 2002). Because the outcome did not include
zeroes and the means were large numbers, we did not use
a Poisson regression. Speciically, we estimated one main
efects model and four interaction models for each outcome,
for ive total models per outcome. Because we estimated
multiple models, we followed guidelines of the Bonferroni correction and used an adjusted alpha (α = 0.0125).
To examine model it, we compared changes in R2. This
process revealed that for all four outcomes, the main efects
13
models were the best itting models. We examined assumptions associated with OLS. Residuals from the main efects
models did not appear to be normally distributed (Shapiro–Wilk p > .05); kurtosis values of the residuals for two
models exceeded three. However, given that regression is
robust to violations of normality, that skewness values did
not violate normality, and that we used an adjusted alpha, we
determined that there is little concern for a Type I error (i.e.,
detecting a statistically signiicant relationship when one
does not actually exist). The White test revealed that residuals were homogenous, and the Durbin–Watson test indicated
an absence of irst-order autocorrelation and therefore, no
violation of independence. Additionally, using studentized
residuals and Cook’s D, we identiied no inluential outliers. Although there were four instances of strong zero-order
correlations (range of − 0.548 to 0.790), all tolerance values of the best itting models exceeded 0.20, providing no
evidence of issues with multicollinearity (Tabachnick and
Fidell 2006).
Results
Table 1 includes descriptive statistics for the 473 children
in the sample. There were more males (82.2%) than females
(17.8%), most children had a diagnosis of Intellectual Disability (68.9%), and a minority of children had a diagnosis
of Asperger’s (17.1%). The average age of diagnosis was
approximately 3.5 years, the average age of enrollment was
6 years, and the average ABC score was 65.69. One-third of
children identiied as white (34%) and more than two-thirds
lived in an urban neighborhood (70%). The average time-lag
at Time 1 (Date of Diagnosis to Date on Waitlist) was 333
days, the average time-lag at Time 2 (Date of Enrollment
to Date of Assessment) was 68 days, the average time-lag
at Time 3 (Date of Assessment to Date of Initial Therapy
Session) was 54 days, and the average time-lag at Time 4
(Date of Diagnosis to Date of Initial Therapy Session) was
1041 days.
Two of the four main efects models were signiicant.
Because there were no signiicant interaction models, we
only present results of the main efects models (Table 2).
The irst main efects model (Model 1a) accounted for 77%
of the variability in the number of days at Time 1 (Date of
Diagnosis to Date on Waitlist) [F (20, 452) = 79.94, p < .025,
adj R2 = 0.77]. No primary independent variables were associated with the number of days at Time 1. The variables
with the strongest relationship with number of days were
two covariates, age of diagnosis (β = − 21.57, p < .025,) and
age of enrollment (β = 21.09, p < .025), with semi-partial
correlation values of 0.46 and 0.61, respectively. The second and third main efects model (Model 2a and Model 3a),
or Time 2 (Date of Enrollment to Date of Assessment) [F
J Autism Dev Disord
Table 1 Univariate descriptive statistics for time-lag (four measures), child race–ethnicity, neighborhood characteristics, and covariates (N = 473)
Variable
% (M)
Dependent variables (in days)
Diagnosis to waitlist
(332.67)
Enrollment to assessment (67.53)
Assessment to treatment
(53.57)
Diagnosis to treatment
(1040.89)
Child/family variables
Race–ethnicity
Non-Hispanic white
34.04
Non-Hispanic black
17.55
Hispanic
7.61
Non-Hispanic other
4.02
Unknown
36.79
Payment category
TEFRA
40.80
SSI
51.37
Other
7.82
Female
17.76
(41.59)
Age diagnoseda
(72.96)
Age enrolleda
ABC score
(65.69)
Asperger’s
17.12
Intellectual disability
68.92
Single parent
25.37
Sibling with ASD
5.50
> 2 Children in household 33.19
Neighborhood variablesb
% White
67.87
Poverty
(0)
Aluence
(0)
Urban
69.98
Suburban
25.16
Rural
4.86
a
SD
Sk
strongest relationship with number of days, with magnitudes
of 0.54 and 0.74, respectively.
Ku
Discussion
324.010
59.95
35.60
357.04
1.20
1.29
1.12
0.93
0.43
0.45
1.04
0.08
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
15.99
18.54
13.13
–
–
–
–
–
–
–
–
–
1.16
0.70
0.45
–
–
–
–
–
–
–
–
–
1.25
− 0.06
0.20
–
–
–
–
–
21.53
0.74
0.94
− 1.04
1.05
0.55
0.57
1.34
− 0.53
–
–
–
–
–
–
Age diagnosed and age enrolled are measured in months
b
Poverty and aluence are z-scores, so the mean will always be zero.
The following values are the minimum and maximum values of poverty and aluence, respectively: − 1.15827, 2.95111 and − 1.63869,
2.94162
(20, 452) = 1.26, p > .0025, adj R2 = 0.01] and Time 3 (Date
of Assessment to Date of Initial Therapy Session) [F (20,
452) = 1.56, p > .025, adj R2 = 0.02], were not signiicant.
Finally, the fourth main efects model (Model 4a) accounted
for 87% of variability [F (20, 452) = 163.86, p < .0251, adj
R2 = 0.87] in the number of days at Time 4 (Date of Diagnosis to Date of Initial Therapy Session). Child race–ethnicity and neighborhood variables were not signiicant. As in
the irst model, the covariates age of diagnosis (β = − 25.72,
p < .025) and age of enrollment (β = 25.84, p < .025) had the
The average time-lag between diagnosis and treatment onset
was nearly three years, and results suggest that predisposing
social characteristics, or child race–ethnicity and neighborhood racial composition, poverty, aluence, and urbanicity,
do not predict the time-lag between diagnosis and treatment
onset in South Carolina during the time-period examined.
Models 1a and 4a explain a substantial amount of variability in Time 1 (Date of Diagnosis to Date on Waitlist)
and Time 4 (Date of Diagnosis to Date of Initial Therapy
Session), respectively. However, two covariates, or age of
diagnosis and age of enrollment, accounted for the majority
of variability. It is unlikely that this is attributable to multicollinearity, as residual statistics revealed tolerance values
greater than 0.20 (Tabachnick and Fidell 2006). Certainly,
these relationships point to the necessity of including these
covariates in future research on time-lag. It also suggests
that factors other than predisposing social characteristics
may play a more important role in timely treatment onset.
For example, given that children diagnosed at a later age
experienced a shorter time-lag, it is possible that parents
of older children are more likely to be aware of available
resources and/or to experience a greater sense of urgency to
seek treatment compared to parents of children diagnosed
earlier. That it takes the average parent nearly one year to
request that their child’s name be placed on a waitlist is concerning and underscores the need to explore reasons for this
extensive time-lag.
The current study conlicts with prior research suggesting
that children experience disparities in access to Medicaidfunded EIBI. A detailed review of the diferences between
current and prior indings provides a likely explanation for
why we did not detect evidence of disparities. Shattuck et al.
(2009) compared the census-tract level demographics of
children who enrolled in Wisconsin’s EIBI program to the
general population of the state, and Magaña et al. (2013)
used parent-reported enrollment as an indicator of access
in the same program. In both studies, researchers identiied
disparities by comparing children who did and did not enroll
in the program, whereas in the current sample all children
had enrolled in South Carolina’s program. It is possible,
therefore, that disparities exist among children who do and
do not enroll in Medicaid-funded EIBI, but disparities do
not exist in the time-lag between diagnosis and treatment
onset between children who do enroll. Clearly, enrollment
and time-lag are very diferent indicators of access. In the
current study, data for children whose parents never placed
them on a waitlist, and children whose parents placed them
13
J Autism Dev Disord
Table 2 Estimates from best
itting regression models for
time-lag (N = 473)
Outcome
Model
Main efects
Intercept
Child/family variables
Race–ethnicity
Non-Hispanic black
Hispanic
Non-Hispanic other
Unknown
Payment category
SSI
Other
Female
Age diagnosed
Age enrolled
ABC score
Asperger’s
Intellectual disability
Single parent
Sibling with ASD
> 2 Children in Hsld
Neighborhood variables
% White
Poverty
Aluence
Rural
Suburban
Model it
R2
Adj R2
Time 1
Time 2
Time 3
Time 4
Model 1a, b (SE)
Model 2a, b (SE)
Model 3a, b (SE)
Model 4a, b (SE)
314.40* (20.50)
49.97* (7.86)
61.97* (4.64)
1058.95* (16.75)
16.60 (24.65)
5.97 (29.31)
53.00* (38.52)
− 3.43 (2.50)
15.86 (9.46)
11.08 (11.24)
8.98* (14.78)
1.39 (0.96)
4.06 (5.58)
− 5.48 (6.63)
− 11.95 (8.72)
− 0.53 (0.57)
9.09 (20.14)
− 11.60 (23.95)
35.68 (31.48)
− 1.43 (2.04)
15.85 (18.20)
16.83 (29.26)
− 18.37 (19.09)
− 21.57* (0.70)
21.09* (0.60)
− 0.71 (0.57)
− 0.97 (19.33)
57.06* (16.61)
0.11 (17.84)
− 0.12 (32.28)
− 6.83 (16.00)
3.67 (6.98)
1.62 (11.22)
− 13.11 (7.32)
− 0.19 (0.27)
0.25 (0.23)
0.29 (0.22)
− 7.65 (7.42)
13.81* (6.37)
1.98 (6.85)
− 12.35 (12.38)
6.82 (6.13)
− 7.28 (4.19)
− 6.33 (6.62)
− 4.27 (4.31)
− 0.01 (0.15)
− 0.05 (0.14)
− 0.09 (0.13)
− 5.73 (4.38)
− 1.22 (3.76)
8.13* (4.04)
− 8.94 (7.31)
− 0.28 (3.62)
− 12.77 (0.39)
− 4.97 (23.91)
− 17.51 (15.60)
− 25.72* (0.57)
25.72* (0.49)
− 0.27 (0.47)
− 17.53 (15.80)
4.25 (13.57)
33.12 (14.58)
− 37.48 (26.37)
9.71 (13.07)
− 0.74 (0.48)
3.39 (19.04)
15.92 (13.13)
− 11.89 (34.62)
− 34.63 (17.03)
− 0.03 (0.18)
− 12.50 (7.31)
− 5.68 (5.04)
0.06 (13.28)
0.41 (6.53)
− 0.18 (0.12)
1.16 (4.31)
− 0.97 (2.97)
− 1.96 (7.84)
− 5.66 (3.85)
− 0.54 (0.39)
− 7.44 (15.56)
− 3.69 (10.73)
11.03 (28.29)
− 6.91 (13.91)
0.7796
0.7698
0.0527
0.0108
0.0646
0.0232
0.8788
0.8734
Due to extreme values in the outcome most likely due to errors in administrative data entry, we winsorized
the dependent variable at the 95th percentile. All time points are measured in the number of days between
two dates. Time 1 is date of diagnosis to date on waitlist; Time 2 is date of enrollment and to date of
assessment; Time 3 is date of assessment to date of initial therapy session; Time 4 is date of diagnosis to
date of initial therapy session
*p < .0125
on a waitlist but never enrolled, were unavailable. There is
no way to know how many children in South Carolina were
eligible to enroll but never did. In other words, it is possible that a replication of the study by Shattuck et al. (2009)
in South Carolina’s EIBI program would produce similar
indings.
Several factors limit the interpretation of study indings.
First, the current study is an examination of children who
enrolled in South Carolina’s EIBI Medicaid waiver, limiting
generalizability to other states. In addition, the sample did
not include children whose parents placed them on a waitlist but never enrolled in the program because SC DDSN
13
maintained no records on these children other than their
name and social security number. There is no way to determine if the children who never enrolled are qualitatively
diferent from children who did, and prior research suggests
that this is a possibility (Magaña et al. 2013; Shattuck et al.
2009). Finally, limitations of administrative data are evident,
including data entry errors that required the use of winsorizing outcome variables, and although an improvement in data
of this type (Shattuck et al. 2009), the high number of children in the unknown racial category (36.8%). Compared to
the racial distribution in South Carolina, non-Hispanic black
and non-Hispanic white children are underrepresented in the
J Autism Dev Disord
sample. It is likely that most of the children in the unknown
racial category are one or the other, and it is possible that
the high percentage of children in this category inluenced
indings.
Despite limitations, this study lays the groundwork for
future research on the time-lag between diagnosis and treatment onset, and it adds to a nascent body of literature on
access to Medicaid-funded EIBI. Results demonstrate the
importance of conducting research beyond the age of a
child’s diagnosis to the time-lag between diagnosis and treatment onset. In this study, an average of 1041 days—or nearly
three years—lapsed between a child’s diagnosis and initial
therapy session. Notably, nearly one year lapsed before
children’s placement on the SC PDD Program waitlist. This
time-lag is counterintuitive to the urgency placed on providing EIBI to children as early as possible. Recognizing this,
in 2012 SC DDSN collaborated with the South Carolina Act
Early Team to spearhead a unique policy. Children at risk for
ASD as determined by the Modiied Checklist for Autism in
Toddlers and the Screening Tool for Autism in Toddlers and
Young Children who were participating in EIBI through the
state’s Part C EI services at least 30 days prior to their third
birthday bypassed the SC PDD Program waitlist (Rotholz
et al. 2017). Presumptive eligibility enables earlier access
to services without the need for a formal diagnosis. There is
a need to explore the feasibility of similar policies in other
states.
To build on these results, it is necessary to examine timelag between diagnosis and treatment onset in other states
and to investigate factors in addition to predisposing social
characteristics that might contribute to this time-lag (e.g.,
parent perceived need, provider availability), as well as move
beyond children’s initial treatment session to investigate
treatment utilization over time. It is critical to examine if
children receive other therapies while waiting to begin EIBI,
and if so, the type and amount of therapy. Although EIBI has
the strongest evidence for treating ASD, also recommended
are other therapies (e.g., speech-language, occupational, and
physical therapy). Exploring whether or not children receive
these services as a bridge between diagnosis and EIBI treatment onset is worthwhile, not least of which because an
overwhelming majority of states have reported shortages of
speech-language pathologists (82%) and occupational therapists (79%; Wise et al. 2010).
Finally, there are at least two takeaways regarding data
collection for future research and the provision of EIBI.
First, there is a need to enhance the collection of demographic data, especially race–ethnicity. This is not a new
challenge in health services research. In a study that surveyed hospital patients on this issue, 93% of respondents
reported that it is critical to conduct studies that ensure equitable care irrespective of race–ethnicity and 80% of respondents reported that it is important to track race–ethnicity.
However, 31% expressed concern that the information could
be used to discriminate against patients (Baker et al. 2005).
Results of a study by Hasnain-Wynia et al. (2010) indicate
that a solution to this perception is to clearly communicate
through various mediums the reason for requesting patients’
race–ethnicity. In particular, a majority of study participants
were most receptive to the statement, “race/ethnicity information is being collected to ensure that everyone gets highquality care” (2010, p. 378). Adopting this approach when
case managers collect information on children and parents
could prove useful to future data collection and research.
Second, South Carolina is dissolving the SC PDD Program
waitlist as the agency transfers the delivery of EIBI from its
Medicaid waiver to its Medicaid state plan. As South Carolina and other states begin providing EIBI through Medicaid,
it is important to determine how best to capture and record
children’s initial contact with the EIBI service system.
Acknowledgments We acknowledge the South Carolina Department
of Disabilities and Special Needs and the University of South Carolina’s Institute for African American Research for their support of this
work. The views and opinions expressed in this article are those of the
authors and do not necessarily relect the oicial policy or position
of the South Carolina Department of Disabilities and Special Needs.
Funding This study was funded in part by the Institute for African
American Research at the University of South Carolina.
Author Contributions MY conceived of the study, led its design and
coordination, and drafted the manuscript; RH advised MY on conceptualization and data collection and provided feedback on subsequent
manuscript drafts; BB advised MY on statistical analyses and interpretation and provided feedback on manuscript drafts; All authors read and
approved the inal manuscript.
Compliance with Ethical Standards
Conlict of interest
of interest.
The authors declared that they have no conlict
Ethical Approval This article does not contain any studies with
human participants or animals performed by any of the authors.
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