This increase was largely the result of an increase in the prevalence of children diagnosed with a developmental delay other than autism spectrum disorder (ASD) or intellectual disability, a rise from 3.57% in 2014 to 4.55% in 2016.
Over the same period, there was no significant change in the prevalence of diagnosed ASD (2.24% in 2014 and 2.76% in 2016) or intellectual disability (1.10% in 2014 and 1.14% in 2016).
The latest prevalence estimates for diagnosed ASD, intellectual disability, and other developmental delay among children aged 3 to 17 years are from National Health Interview Survey (NHIS) data. These estimates are lower than those described in previous reports that used NHIS data, the authors note in their November 29 NCHS data brief.
The current report uses a "more restrictive definition for a developmental disability that does not include conditions such as attention-deficit/hyperactivity disorder or learning disabilities, which may account for differences in estimates," Benjamin Zablotsky, PhD, and colleagues from the NCHS explain in the brief.
In this study, "developmental disabilities are a set of heterogeneous disorders characterized by difficulties in one or more domains, including but not limited to, learning, behavior, and self-care.... Estimates are also presented for any developmental disability, defined as having had one or more of these three diagnoses [diagnosed autism spectrum disorder, intellectual disability, and other developmental delay]," the researchers write.
For each development disability examined in the new report, the prevalence was significantly higher among boys than girls, a finding common in children diagnosed with a developmental disability, the researchers say.
The prevalence of ASD was 3.63% among boys and 1.25% among girls; the prevalence of any developmental disability was 8.15% and 4.29%, respectively.
Hispanic children had the lowest prevalence of any developmental disability diagnosis compared with all other race and ethnicity groups. "Racial and ethnic disparities in the prevalence of developmental disabilities are findings commonly reported in the scientific literature," the researchers point out.
The prevalence of developmental disability varied among different age groups, with the highest prevalence in children aged 3 to 7 years (4.37%) and lowest in children aged 13 to 17 years (3.08%).
This "may reflect recent improvements in awareness and screening for developmental delay, resulting in younger cohorts having a higher diagnosed prevalence. However, for some children with less severe impairment, developmental disabilities, such as autism spectrum disorder and intellectual disability, may not be diagnosed until the child enters school and is observed by trained teachers," the authors note.
These latest prevalence estimates are based on parent or guardian reports of their child ever receiving a diagnosis of each development disability from a physician or other health provider.
Source:
National Center for Health Statistics. Data Brief 291. Published online November 29, 2017. Full text
Comment: Alarming results of Big Pharma & the CDC in America: 1 in 6 children now has a developmental disability