Epidemiologic Assessment of Developmental Delays

Report Goal: Includes psychometric evaluation of screening instruments for autism Report Description: This report details results for Aim 4b

Autism Screeners

MCHAT Scoring

The MCHAT consists of a series of questions designed to identify children who should receive a more thorough assessment for possible early signs of autism spectrum disorder (ASD) or developmental delay.

Within the MCHAT assessment, there are 17 regular items and 6 critical items. If a child fails two or more critical items or any three items it is recommended that they receive a more thorough evaluation.

Proportions of MCHAT Results

              At Risk Not At Risk
Frequency  38.0000000 192.0000000
Proportion  0.1652174   0.8347826

ASRS Scoring

The ASRS consists of a series of questions that scale observed behaviors in areas such as socialization, communication, unusual behaviors, behavioral rigidity, sensory, sensitivity, and self-regulation.

Using the raw scores from the ASRS, children with a score of 31 or more are classified as having a “Very Elevated” risk of developing autism spectrum disorder (ASD). Children with scores of 21 or more are classified as “Slightly Elevated”.

ASRS Scoring (Slightly Elevated Risk and Above)

ASRS Scoring (Very Elevated Risk)

ASRS Poportions of results

           Not At Risk Slight Risk Very Elevated Risk
Frequency   22.0000000 102.0000000          42.000000
Proportion   0.1325301   0.6144578           0.253012

CSBS Scoring

CSBS Proportions of results

               At Risk Not At Risk
Frequency  200.0000000 420.0000000
Proportion   0.3225806   0.6774194

Agreement Between Measures

The Kappa Coefficient measures agreement between measures, with higher values meaning greater agreement.

The judgments associated with the Kappa are explained as “given by Landis JR, Koch GG (1977) Biometrics, 33: 159-174: If kappa is less than 0, "No agreement”, if 0-0.2, “Slight agreement”, if 0.2-0.4, “Fair agreement”, if 0.4-0.6, “Moderate agreement”, if 0.6-0.8, “Substantial agreement”, if 0.8-1.0, “Almost perfect agreement”.“

Inter-Measure Agreement between the CSBS and MCHAT

             MCHAT
CSBS          At Risk Not At Risk
  At Risk          23          52
  Not At Risk      15         140

$Result

    Estimate Cohen's kappa statistics and test the null hypothesis that the extent of agreement is same as random (kappa=0)

data:  CsbsMCHAT
Z = 2.8772, p-value = 0.002006
95 percent confidence interval:
 0.08741751 0.39360762
sample estimates:
[1] 0.2405126


$Judgement
[1] "Fair agreement"

Inter-Measure Agreement between the ASRS and MCHAT

ASRS result: 'Slight Risk'

             MCHAT
ASRS-slight   At Risk Not At Risk
  At Risk           1          17
  Not At Risk       0           1

$Result

    Estimate Cohen's kappa statistics and test the null hypothesis that the extent of agreement is same as random (kappa=0)

data:  ASRSSlightMCHAT
Z = 0.0806, p-value = 0.4679
95 percent confidence interval:
 -0.1471246  0.1594323
sample estimates:
[1] 0.006153846


$Judgement
[1] "Slight agreement"

ASRS result: 'Very Elevated Risk'

             MCHAT
ASRS-Extreme  At Risk Not At Risk
  At Risk           0           6
  Not At Risk       1          12

$Result

    Estimate Cohen's kappa statistics and test the null hypothesis that the extent of agreement is same as random (kappa=0)

data:  ASRSExtremeMCHAT
Z = -0.3069, p-value = 0.6206
95 percent confidence interval:
 -0.7462851  0.5479380
sample estimates:
[1] -0.09917355


$Judgement
[1] "No agreement"