Tuesday, August 16, 2011

Autism: to screen or not screen?

The August 15th issue of AFP features a pair of editorials that stake out opposite positions in the intensifying debate about the benefits of routinely screening young children for autism spectrum disorders (ASDs). Dr. Paul Lipkin and Susan Hyman argue that the rising incidence of ASDs and studies suggesting a benefit from early diagnosis and behavioral interventions make it imperative for pediatricians and family physicians to incorporate developmental screening tools into their practices. They assert that developmental screening does not impose significant time burdens on physicians, and that false-positive screening results can be minimized by scheduling follow-up interview visits.

On the other hand, Dr. Doug Campos-Outcalt counters that screening for ASDs has not yet met several critical criteria for establishing the effectiveness of a screening test. In particular, the following important questions remain unanswered:

1) What are the sensitivity and false-positive rate of the best screening test for ASDs available in an average clinical setting?

2) How much earlier can screening tests detect ASDs compared with an astute clinician who asks a few key questions about, and acts on, parental concerns regarding a child's communication and interactions?

3) What are the potential harms of testing?

4) Does earlier detection by screening result in meaningful and long-lasting improvements compared with detection through routine care?

Although a recent systematic review published in Pediatrics found limited evidence that early intensive behavioral interventions improve "cognitive performance, language skills, and adaptive behavior skills in some young children with ASDs," it remains uncertain if routine screening leads to improved outcomes. Therefore, Dr. Campos-Outcalt recommends, "Family physicians who provide care for young children should ask parents about any concerns, be alert for the signs and symptoms of ASDs, and use available diagnostic testing tools to assist in making clinical decisions when an ASD is suspected."