Factors associated with the age of diagnosis among children with autism spectrum disorders

1
Factors associated with the age of diagnosis
among children with autism spectrum disorders
Cynthia D. Zubritsky, PhD Maytali M. Novak, MA
David S. Mandell, ScD In press as Mandell DS,
Novak MM, Zubritsky CD. Factors associated with
age of diagnosis among children with autism
spectrum disorders. Pediatrics.
Median age of diagnosis by diagnostic and age
categories
Linear regression predicting age of diagnosis in
years

Coefficient

95 Confidence
2
Adjusted R
0.54

Interval

Diagnosis



1.8

Aspergers disorder

0.8, 2.9

Pervasive developmental disorder

0.2

-
0.1, 0.6

0.4

Interaction of Aspergers diagnosis and age

0.3, 0.5

Demographics



Male

0.2

-
0.2, 0.6

0.2

Age (years)

0.1, 0.2

African American

0.1

-
0.7, 0.4

Age of diagnosis (years)
Asian/Pacific Islander

-
0.5

-
1.5, 0.4

Native American

0.0

-
0.9, 0.9

Latino

-
0.8

-
1.6, 0.1

0.8

Child was adopted

0.2, 1.5

0.4

Rural

0.1, 0.7

Suburban

0.2

-
0.2, 0.6

Income below poverty level

0.2

-
0.2, 0.7

0.9

Income from poverty level to 100 above

0.5, 1.2

Symptoms



Doesnt respond when called

0.0

-
0.4, 0.4

10 13
14 - 17
18 -21
6 - 9
2 - 5
Self- injurious
-
0.2

-
0.5, 0.1

-
1.2

Severe language deficits

-
1.5,
-
0.8

0.6

Oversensitive to pain

0.2, 0.9

Aggressive to others

-
0.1

-
0.4, 0.2

• Near poor children are diagnosed later than
  wealthier or poorer children.
• Children living in rural areas are diagnosed
  later than those living in urban areas.
• Only certain ASD-related behaviors, some of which
  are not required to satisfy diagnostic criteria,
  were associated with decreased age of diagnosis.
• Children with fewer pediatricians were diagnosed
  earlier, as were children whose pediatricians
  referred them to specialists in response to
  developmental concerns.
• The average age at which children are diagnosed
  is decreasing, but the range at which Aspergers
  disorder is diagnosed is increasing.

Insists on sameness

-
0.1

-
0.4, 0.3

-
0.3

Sustained odd play

-
0.6,
-
0.1

Echolalia

-
0.2

-
0.5, 0.0

-
0.4

Hand flapping

-
0.7,
-
0.1

-
0.2

Toe walking

-
0.5,
-
0.1

Spins self

-
0.1

-
0.4, 0
.2

Other clinical features



Mental retardation

-
0.2

-
0.6, 0.2

0.8

Hearing impairment

0.1, 1.6

Seizures

0.0

-
0.5, 0.5

Health system characteristics



2 primary care physicians prior to diagnosis

0.0

-
0.3, 0.3

3 primary care physicians prior to diagnosis

0.0

-
0.4, 0.4

• Importance of having a regular source of
  pediatric care specialist referrals.
• Lack of finding for developmental tests is
  disappointing may relate to data collection
• Income may be related to insurance status, with
  near poor families least likely to be insured or
  to have insurance that fully covers needed
  services.
• Paucity of services in rural areas.
• Clinical profile associated with earlier
  diagnosis suggests need for continued physician
  education.

0.5

4 primary care physicians prior to diagnosis

0.1, 1.0

In response to concerns about development



physician conducted developmental tests

-
0.2

-
1.0, 0.6

-
0.3

physician referred to a specialist

-
0.7, 0.0

Interaction of developmental testing and referral

0.3

-
0.6, 1.3


Statistically significant findings at p 0.05
are presented in bold typeface Reference group
consists of female European Americans diagnosed
with autistic disorder, living in urban settings
with household incomes more than 100 above the
federal poverty level.