Identifying ASD and Comorbid Conditions: Joint Use of the SDQ and CSBQ

Background:

There are many screeners designed to identify developmental disabilities, externalizing, and internalizing conditions. However, many existing studies are limited by small sample sizes, focus on single instruments, are limited in the numbers of conditions considered, and often use of cut-off scores of other screeners or assessments, rather than actual diagnostic groups, as predicted outcomes.

Objectives:

This study investigates the predictive validity of a measure of externalizing and internalizing conditions, the Strengths and Difficulties Questionnaire (SDQ), and a measure of problems commonly seen in children with developmental disabilities, the Children’s Social Behavior Questionnaire (CSBQ). Specifically, in a group of children with ASD, developmental delays (DD), and intellectual disabilities (ID), we hypothesize that the SDQ externalizing subscales would most strongly predict conduct problems and co-morbid attention deficit disorder (ADD), the SDQ internalizing subscales would most strongly predict co-morbid anxiety problems and depression, and CSBQ scales would most strongly predict ASD diagnosis.

Methods:

We used national data from the Survey of Pathways to Diagnosis and Services to examine the predictive validity of the SDQ externalizing (conduct and attention problems) and internalizing (emotion and peer problems) sub-scales, and the CSBQ subscales (behavior/emotions not in tune to social environment, social contact/interest, orientation problems, social information processing, stereotypy, fear/change-resistance) in children with ASD, DD, and ID (n=2370). Analyses were weighted and stratified binary logistic regression models predicting the following separate outcome variables: parent reported ASD diagnosis, conduct problems, ADHD, anxiety problems and depression. All models statistically controlled for the following variables: gender; federal poverty level; age; race/ethnicity (White, Black, Hispanic, Other); maternal education; insurance status (private, public, and none); and English Language status (English speaking, non-English speaking).

Results:

Results of logistic regression generally supported the validity of the SDQ externalizing and internalizing subscales in groups of children with ASD, DD, and ID: Specifically, the SDQ conduct problems subscale was the only SDQ scale predictive of conduct problems (aOR = 1.43 95%CI[1.14-1.80]); the SDQ attention problems scale was the only SDQ scale predictive of ADHD (aOR = 1.43 95%CI[1.27-1.60]); the SDQ emotion problems scale was the only SDQ scale predictive of depression (aOR = 1.41 95%CI[1.25-1.60]) and anxiety (aOR = 1.41 95%CI[1.22-1.63]). The SDQ peer problems (aOR = 1.17 95%CI[1.01-1.37]), conduct problems (aOR = 0.74 95%CI[0.61-0.89]), and prosocial (aOR = 0.70 95%CI[0.60-1.80]) scales also predicted ASD diagnosis.

The CSBQ scales orientation problems positively (aOR = 1.08 95%CI[1.00-1.17]) and fear/change-resistance negatively (aOR = 0.84 95%CI[0.72-0.98]) predicted co-morbid ADD; social contact/interest (aOR = 0.90 95%CI[0.82-0.98]) negatively predicted comorbid depression; fear/change-resistance (aOR = 1.23 95%CI[1.01-1.49]) positively predicted ASD diagnosis.

Conclusions:

Data from this study indicates that some SDQ subscales may be useful for identifying externalizing and internalizing conditions in children with ASD, DD, and ID. Future research should determine whether the specific subscales versus the broader externalizing and internalizing subscales are preferred in this population. Furthermore, more research on the clinical utility of the CSBQ subscales is needed.