Browsing by Author "Roman Urrestarazu, Andrés"

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    Autism Prevalence in Chile: Unmet Special Education Needs using Data Linkage and Bayesian Analysis of Three Million School-Aged Children
    (2024) Roman Urrestarazu, Andrés; Tyson, A.; Gatica Bahamondes, Gabriel Guillermo; van Kesse, R.; Yang, J.; Mansilla, C.; Zuniga, I.; Mendez-Fadol, A.; Larrain, B.; Garcia, R.; Koch, D.; Groot, W.; Pavlova, M.; Czabanowska, K.; Ford, T.
    Prevalence estimates of autism spectrum disorder (henceforth autism) in Latin America thus far have been limited by a lack of reliable population-level data. We analyzed autism school prevalence across 29 Chilean health service regions for students aged 6–18 years, standardized by age and sex. We validated these results using electronic health records from one of Chile’s largest regional health service, the Servicio de Salud Araucania Sur (SSAS). We then projected Bayesian prevalences, reporting nationally, and by health service, ethnicity, immigration background, and rurality. We found a standardized national school autism prevalence of 0.46% (95% CI, 0.46%-0.47%), with boys having six times higher odds of autism than girls (OR 6.10 [95%CI: 5.82–6.41]). The sex - and age-adjusted clinical prevalence in the SSAS trust was 1.22% (95% CI: 1.16%-1.28%) and the projected Bayesian national autism prevalence was 1.31% (95% Credible Interval: 1.25%-1.38%). Our results indicate a higher autism prevalence than previously reported in the south of the Araucania region with observed disparities in prevalence across sex, ethnic groups, and health services.
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    Testing an online screening for autism in the COVID-19 pandemic: a psychometric study of the Q-CHAT-24 in Chilean toddlers
    (FRONTIERS MEDIA SA, 2024) Gatica Bahamondes, Gabriel Guillermo; Mendez Fadol, Alejandra; Sanchez Sepulveda, Francisca; Penailillo Diaz, Constanza; van Kessel, Robin; Czabanowska, Katarzyna; Roman Urrestarazu, Andrés
    Background: The aim of this study was to examine some psychometric characteristics of the Chilean-adapted version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT-24) (24) in a group of unselected children (community sample). This version was administered remotely through an online version during the pandemic period to caregivers of children, aged 18-24 months, registered in four primary care polyclinics of the Health Service Araucan & iacute;a Sur, Chile. Methods: An intentional non-probabilistic sampling was used. Three hundred and thirteen toddlers were examined. Participants completed an online version of the Q-CHAT-24 which was disseminated through the REDCap platform. Evidence of reliability through internal consistency and evidence of predictive validity through ROC curve analysis were realized. Results: The mean age of the children evaluated was 21.16 months. The Shapiro-Wilk test revealed that Q-CHAT-24 scores was normally distributed. 71 cases (23.12%) scored 38 points or more on the Q-CHAT-24, qualifying as Autistic Risk. 48 cases (15.63%) were confirmed as autistic through the ADOS-2 Module T. All items were positively correlated with Q-CHAT-24 total score. All items were positively correlated with Q-CHAT-24 total score. Internal consistency was acceptable for the Q-CHAT-24 (Cronbach s alpha=0.78). The internal consistencies were analyzed for the Q-CHAT-24 Factors, and they were good for factor 1 "Communication and Social Interaction" (Cronbach s alpha=0.85) and acceptable for factor 2 "Restrictive and Repetitive Patterns" (Cronbach s alpha=0.74). Receiver operating characteristic (ROC) curve analyses were performed. The AUC values were 0.93 with statistical significance (p<0.01). For the cut-off point of 38, the Sensitivity, Specificity and Youden index values were 0.89, 0.8 and 0.7, respectively. The Positive Predictive Value (PPV) was 86% and the Negative Predictive Value (NPV) was 85%. Conclusions: In accordance with the objectives of this study, evidence of reliability and predictive validity was demonstrated for the Q-CHAT-24 in this Chilean population. More importantly, this study provides Sensitivity and Specificity data for a remote application version of an autism screening tool already validated in Chile. The implications of this have to do with the possibility of establishing a remote assessment system for children at risk of autism on a population scale.