Prevalence of autism in mainland China, Hong Kong and Taiwan: a systematic review and meta-analysis

Abstract

BackgroundThe prevalence of autism spectrum conditions (ASC) is 1% in developed countries, but little data are available from mainland China, Hong Kong and Taiwan. This study synthesizes evidence relating to the prevalence of ASC in these areas and assesses the effects of research methodology on prevalence estimates.MethodsSystematic literature searches were conducted in PubMed, Web of Knowledge, China Web of Knowledge and Weipu databases, as well as relevant papers published from 1987 to 2011, reporting prevalence estimates of ASC or childhood autism in mainland China, Hong Kong and Taiwan. Summary estimates of prevalence were calculated with a random effects model. The effects of research methodology on the prevalence estimates were assessed using a meta-regression model.ResultsThere were 25 studies eligible for review, 18 of which were suitable for inclusion in a meta-analysis. Pooled prevalence of childhood autism was 11.8 per 10,000 individuals (95% confidence interval (CI): 8.2, 15.3) in mainland China. Pooled prevalence of ASC was 26.6 per 10,000 (95% CI: 18.5, 34.6) in three areas. Substantial heterogeneity was identified between studies (I2>75%). The prevalence estimate of childhood autism was most strongly associated with the choice of screening instrument. After adjustment for age group, the odds ratio for prevalence estimates when using the Autism Behavior Checklist (ABC) as the screening instrument compared with those using the Clancy Autism Behavior Scale (CABS) was 0.29 (95% CI: 0.12, 0.69), and 1.79 (95% CI: 0.70, 4.55; P= 0.20) when using the Checklist for Autism in Toddlers (CHAT) compared to the CABS.ConclusionsThe available studies investigating the prevalence of ASC in China, Hong Kong and Taiwan have focused mainly on childhood autism rather than the whole spectrum. The prevalence estimates are lower than estimates from developed countries. Studies using more recently developed screening instruments reported higher prevalence than older ones. However, available studies have methodological weaknesses and therefore these results lack comparability with those from developed countries. Our findings indicate a potential under-diagnosis and under-detection of ASC in mainland China, Hong Kong and Taiwan, and a need to adopt more advanced methods for research of ASC in these areas.

Psychometric properties of the Chinese version of the Psychoeducational Profile – Third Edition – Caregiver Report

“…However, the Hong Kong Government's estimation of the prevalence rate of ASD was on the low side (The Rehabilitation Advisory Committee, 2005). Based on a metaanalytic study, Sun et al (2013) concluded that there was a potential underdiagnosis and underdetection of ASD in Chinese societies. It has also been argued that the available studies suffered methodological weaknesses, such as small sample size, divergent conceptual principles, and inconsistent measurement tools (Sun et al, 2013).…”

“…Based on a metaanalytic study, Sun et al (2013) concluded that there was a potential underdiagnosis and underdetection of ASD in Chinese societies. It has also been argued that the available studies suffered methodological weaknesses, such as small sample size, divergent conceptual principles, and inconsistent measurement tools (Sun et al, 2013). This has pointed to the need to use more advanced methods to study ASD in Chinese contexts.…”

Current status and challenge in clinical work of autism spectrum disorders in China

“…In 2013, Sun et al assessed the prevalence of childhood autism in China including Hong Kong and Taiwan regions based on 18 epidemiological studies from 1987 to 2011. They estimated the pooled prevalence of autism in children as 11.8/10,000 in the Mainland of China and 26.6/10,000 in all of China [4]. In the same year, a meta-analysis of the studies (excluding the only nationwide study) reported a pooled estimated prevalence of ASD of 24.5/10,000 in the Mainland of China [5].…”

“…Children suspected with developmental delay or ASD will be taken to our department for further assessment; (2) pediatricians in our department interview the parents to get the message of symptoms of concern and some basic information about the child's developmental history; (3) then the doctor may conduct a structured observation and apply some basic screening assessments on the child to evaluate whether the concerns are valid or not. (4) based on the screening results, if a red flag shows there are valid concerns, we will make an official diagnosis according to the diagnostic criteria or make an appointment for ADOS and/or ADI-R assessment if possible; (5) the children diagnosed with ASD will be assessed with other scales such as Psychological Educational Profile 3rd Edition (PEP-3) and Griffiths Development Scales Chinese Edition or Wechsler's Intelligence Scale IV to collect the information about the abilities of multi-domains. After assessments, we will discuss with the parents about the individual educational plan for their children.…”

“…Some clinicians consider the screening results to be the final diagnosis without using any additional diagnostic instruments [8]. Some adopted the Childhood Autism Rating Scale (CARS) as the diagnostic instrument [4].…”