News and Knowledge

The newly developed Psychological Development Questionnaire (PDQ-1) could help pediatricians and other primary care providers identify autism more efficiently than the test currently used, the Modified Checklist for Autism in Toddlers – Revised with Follow Up (M-CHAT R/F), which requires an additional follow-up phone interview before determining whether an evaluation is necessary.

A research study conducted by Walter Zahorodny, Ph.D., et al. at Rutgers New Jersey Medical School showed that the PDQ-1 had a positive predictive value (PPV) of 91 percent, with high specificity in low risk populations (99 percent). A PPV indicates the likelihood that an individual truly has a disorder after being screened positive.

Although the M-CHAT R/F was specifically designed to maximize sensitivity to detect as many autism cases as possible, it has been criticized for generating a high rate of false positives. According to Spectrum News, the rate continues to remain high in part due to the lack of proper follow-up.

Alternatively, the two-minute questionnaire may be more widely used since it does not require a follow-up interview. Although the American Academy of Pediatricians recommends that all children be screened for ASD at 18 to 24 months, it is estimated that only half of all children in that age range receive screening.

In the study, the researchers screened 1,959 children between the ages of 18 and 36 months who were not previously known to have any developmental problems. Children who scored low on the PDQ-1 were given comprehensive developmental evaluations to determine diagnosis. While the screening was shown to have 91 percent accuracy in identifying children with ASD across ages 18 to 36 months, it accurately diagnosed 100 percent of the children within the age range of 31 to 36 months with ASD.

While it takes a formal evaluation to fully determine if a child has ASD, the PDQ-1 could be a more practical alternative to current screening methods, allowing for earlier detection.

In the Disability Scoop article, Dr. Zahorodny pointed out, “Effective screening is but the first step toward diagnosis. If we want to improve early detection, easy-to-use and reliable autism screeners need to be widely used.”