Dejan Stevanovic, Rajna Knez, Tatjana Zorcec, Marija Anderluh, Jana Kodrič, Petar Petrov, Feriha Hadžagić Ćatibušić, Azra Deljković, Slavica Brkic Cvetkovic, Nikolina Vrljičak Davidovic, Radenka Kuzmanić Šamija, Ana Đorić, Christopher Gillberg

The Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations - Questionnaire (ESSENCE-Q) was developed as a brief screener to identify children with developmental concerns who might have neurodevelopmental disorders (NDDs). This study aimed to translate the ESSENCE-Q into south Slavic languages, namely, Bosnian, Bulgarian, Croatian, Macedonian, Montenegrin, Serbian, and Slovenian, and to evaluate its psychometric properties for screening purposes in clinical settings. In the study, the ESSENCE-Q was completed for 251 "typically developing" children and 200 children with 1 or more diagnosed NDDs, all aged 1-6 years. Internal consistency and construct validity were tested first, followed by generating receiver operating characteristic curves and the area under the curve. Optimal cutoff values were then explored. The Cronbach's α coefficients were 0.91, 0.88, and 0.86 for ESSENCE-Q parent-completed form, and the telephone and direct interview forms administered by trained nurse or specialist, respectively. The 3 versions produced area under the curve values (95% confidence interval): 0.96 (0.93-0.99), 0.91 (0.86-0.95), and 0.91 (0.86-0.97), respectively. An optimal cutoff for ESSENCE-Q parent-completed form was found to be ≥3 points, while for the telephone and direct interviews, it was ≥5 points. We found adequate measurement properties of the south Slavic languages versions of the ESSENCE-Q as a screener for NDDs in clinical settings. This study provided additional data supporting sound psychometric properties of the ESSENCE-Q.