title: Prevalence of tics in schoolchildren in central Spain: a population-based study.
abstract: Tic disorders constitute a neurodevelopmental disorder of childhood. This study sought to determine the prevalence of tic disorders in a school-based sample. A randomized sample of 1158 schoolchildren, based on clusters (classrooms) in the province of Burgos (Spain), was identified on a stratified sampling frame combining types of educational center and setting (mainstream schools and special education), using a two-phase approach (screening and diagnosis ascertainment by a neurologist). Tics with/without impairment criterion were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders criteria. In mainstream schools, tics were observed in 125/741 students (16.86%; 95% confidence interval, 14.10-19.63), and were more frequent in boys (87/448, 19.42%; 95% confidence interval, 15.64-23.19) compared with girls (38/293, 12.96%; 95% confidence interval, 8.95-16.98; P = 0.03). In special education centers, tics disorders were observed in 11/54 of children (20.37%; 95% confidence interval, 8.70-32.03). Overall, tics with impairment criteria were less frequent than tics without impairment criteria (4.65% vs 11.85%, P < 0.0001). The most frequent diagnoses involved chronic motor tics (6.07%) and Tourette syndrome (5.26%). Tic disorders are common in childhood, and the use or nonuse of impairment criteria exerts a significant impact on tic prevalence estimates.
authors.affiliation: Department of Neurology, Hospital General Yagüe, Burgos, Spain. esthercubo@gmail.com
authors.forename: Esther
authors.initials: E
authors.lastname: Cubo
authors.forename: José María Trejo
authors.initials: JM
authors.lastname: Gabriel y Galán
authors.forename: Vanesa Ausín
authors.initials: VA
authors.lastname: Villaverde
authors.forename: Sara Sáez
authors.initials: SS
authors.lastname: Velasco
authors.forename: Vanesa Delgado
authors.initials: VD
authors.lastname: Benito
authors.forename: Jesús Vicente
authors.initials: JV
authors.lastname: Macarrón
authors.forename: José Cordero
authors.initials: JC
authors.lastname: Guevara
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
mesh_terms: D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D013334:Students / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D013981:Tic Disorders / Q000175:diagnosis* / Q000453:epidemiology*