Early screening of childhood ASD at primary care hospitals in western China：A multi-center study in Chengdu, Sichuan Province
Wenxu Yang 1 , Lan Zhang1 , Yang Qiu2 , Jiao Le1 , Ying Zhang3 , Ping Yang4 , Chunxia Zhao5 , Chunhua Du6 , Junni He7 , Yanmei Cao8 , Jia Shang9 , Li Li10 , Yan Liu11 , Shenglan Wu12 , Xia Li13 , Xiujin Chen14 , Hai Lan15 , Hua Li16 , Xiang Kong17 , Hengli Li18 , Defang Mi19 , Jie Zhao20 , Yang Nie21 , Jinxiu Gao22 , Shiwen He2 , Die Tang2
1. 成都市妇女儿童中心医院
2. 四川大学
3. 成都市金牛区妇幼保健院（成都市金牛区妇幼保健计划生育服务中心）
4. 成都市新都区妇幼保健院
5. 天府新区华阳社区卫生服务中心
6. 成都市龙泉驿区妇幼保健院
7. 成都市武侯区妇幼保健院
8. 大邑县妇幼保健院
9. 成都市成华区妇幼保健院
10. 成都市温江区妇幼保健院
11. 金堂县妇幼保健院（金堂县妇女儿童医院）
12. 成都市锦江区妇幼保健院（成都市锦江区妇产科医院）
13. 成都市双流区妇幼保健院
14. 简阳市妇幼保健院
15. 彭州市妇幼保健计划生育服务中心（彭州市妇幼保健院）
16. 成都市青白江区妇幼保健院
17. 邛崃市妇幼保健院
18. 浦江县妇幼保健院
19. 都江堰市妇幼保健院
20. 成都市郫都区妇幼保健计划生育服务中心（成都市郫都区妇幼保健院）
21. 崇州市妇幼保健院
22. 成都市新津区妇幼保健计划生育服务中心
Autism spectrum disorder (ASD) prevalence is increasing rapidly, the screening efficacy of ASD at primary care hospital directly affects diagnostic efficacy. Currently, early ASD screening capacity and the knowledge of ASD epidemiology in western China are limited. In this study we assessed the efficacies of four different ASD screening methods at primary care hospital in Chengdu. The purpose of our study was to estimate the prevalence of autism spectrum disorder in Chengdu and improve the screening model on the child health care network.
We recruited children 18-48 months through 20 primary care hospitals in Chengdu. Warning sign checklist (including autism warning sign and social behavior observation), the Chinese-validated version of the Checklist for Autism in Toddlers (CHAT23), and autism behavior checklist (ABC) were utilized to identify potential ASD cases. A positive result from any one of the four screening methods was defined as a positive case. A secondary assessment by a different doctor was performed on identified cases; an affirmative assessment result leads to a referral to tertiary hospital, whereas different (negative) assessment result requiring further assessment was recorded as non-case for the purpose of this study. Confirmation diagnosis was conducted at tertiary hospitals by gold standard diagnostics tools (ADOS and/or ADIR) on the base of DSM-V. ROC curves and multivariate linear regression were conducted to compare efficacies of screening methods and to identify factors for positive ASD diagnosis.
Out of recruited 14,298 children from 20 primary care hospitals in Chengdu, 13,458 (94.1%) provided sufficient information. The study population consisted of more males (7078, or 52.6%) than females (6380, or 47.4%), with an average age of 21.18±3.46 months. A total of 107 children were diagnosed with ASD, including 83 (1.2%) males and 24 (0.4%) females, with an average age of 30.80 ± 7.55 months. The estimated ASD prevalence was 0.79% in Chengdu. The prevalence in males was higher than that in females, with a male to female ratio of 3.5:1(t = 5.2, p < 0.001). A total of 318 (58.5%) referred children completed clinical diagnosis at tertiary hospitals.
A total of 318 (58.5%) referred children completed clinical diagnosis at tertiary hospitals. Of those completed clinical diagnosis, 107 (107/318, 33.6%) were diagnosed with ASD , and 211(211/318, 66.4%) were diagnosed as non-ASD (including high risk for ASD but did not meet diagnostic criteria, intellectual disability and developmental language disorder). Of the 107 confirmed ASD cases, 87(87/107, 81.3%) were evaluated based on DSM-5 by either ADOS or ADOS+ADI-R, and 20(20/107, 18.7%) were only made by DSM-5. Of these non-ASD, 69(69/211, 32.7%) were evaluated based on DSM-5 by either ADOS or ADOS+ADI-R, and 142(142/211, 67.3%) were only made by DSM-5. Children with eventual positive diagnosis (ASD cases) and children who received a negative diagnosis (non-ASD) obtained statistically different ADOS and ADIR scores (p<0.001), except in the “play” domain (C domain, p=0.256).
The areas under ROC curve for screening methods were 0.941 (95% CI 0.937–0.945, p <0.0001), 0.958 (95% CI 0.954-0.961, p <0.0001), 0.963(95% CI 0.960–0.966, p <0.0001) and 0.820 (95% CI 0.807-0.833, p <0.0001) for autism warning sign, social behavior observation, CHAT23and ABC, respectively. The highest Se, Sp, and PPV were obtained by CHAT23 (98.8%), social behavior observation (98.7%) and ABC (40.4) respectively.
The regression result indicates that age was significantly associated with the probability of receiving a positive ASD diagnosis result, with each year associated with an increase of 1.505 times the likelihood of being diagnosed with ASD (p<0.01). Screening result using social behavior observation was also significantly associated with eventual positive diagnosis of ASD, with a positive screening result associated with 2.244 times higher odds of being diagnosed with ASD (p < 0.01). Gender, location of diagnosis, and primary care hospital did not have significant association with ASD diagnosis outcome.
ASD prevalence in Chengdu is similar to earlier reports. CHAT23 and social behaviour observation were more effective screening methods at primary hospital.
