(RxWiki News) The way in which diseases are diagnosed can change, as was recently the case with autism. And these new changes in diagnostic criteria could change how many children are diagnosed with autism.
A recent study found that the prevalence of autism spectrum disorder diagnoses decreased under new criteria for diagnosis.
The researchers suggested that there could be fewer children diagnosed with autism in the future. However, they believe that new criteria could be introduced in the future and alter this effect.
"Discuss new autism criteria with your child's doctor."
The lead author of this study was Matthew J. Maenner, PhD, from the National Center on Birth Defects and Developmental Disabilities of the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia.
The DSM-5 (fifth edition) was recently published, and the criteria for what constitutes an autism diagnosis has changed. For this study, the researchers compared the children's DSM-IV diagnoses with the criteria from the DSM-5.
The DSM-IV included three categories of impairment: social interaction, communication and repetitive behavior or restricted interests. The DSM-5 ASD diagnosis recognizes only two categories of impairment: social communication and restricted, repetitive patterns of behavior, interests or activities.
The DSM-IV criteria only focused on current behavior, while the DSM-5 criteria consider both past and current behaviors.
In addition, the DSM-5 requires a patient to meet more stringent criteria in the social communication category.
The study included 6,577 8-year-old children (5,452 boys and 1,125 girls) diagnosed with autism spectrum disorder (ASD) based on DSM-IV-TR criteria (fourth edition of the Diagnostic and Statistical Manual of Mental Disorders).
Dr. Maenner and colleagues found that 5,339 participants (81 percent) met the DSM-5 criteria for ASD.
The researchers found that 79 percent of the participants met the DSM-5 criteria in 2006 and 83 percent met the criteria in 2008.
A total of 81 percent of the boys and 80 percent of the girls met the DSM-5 criteria.
The researchers also discovered that 87 percent of the participants with intellectual disability met the DSM-5 criteria versus 83 percent of the participants with an IQ greater than 70.
It was determined that the ASD prevalence estimate in 2006 using DSM-5 criteria was 7.4 cases per 1,000 people versus 9.0 cases per 1,000 people using the DSM-IV criteria.
For 2008, the ASD prevalence estimate using DSM-5 criteria was 10.0 cases per 1,000 people versus 11.3 cases per 1,000 people using the DSM-IV criteria.
“Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new criteria,” the authors concluded.
These authors noted that their study was limited because it relied on symptoms documented in records by health professionals that used DSM-IV criteria.
This study was published on January 22 in JAMA Psychiatry.
The Autism Science Foundation and the Centers for Disease Control and Prevention provided funding.