Epidemiology and Biostatistics Unit, Institute for Maternal and Child Health - IRCCS "Burlo Garofolo", Trieste, Italy.
PLoS One. 2012;7(10):e48082. doi: 10.1371/journal.pone.0048082. Epub 2012 Oct 31.
Although dyslexia is one of the most common neurobehavioral disorders affecting children, prevalence is uncertain and available data are scanty and dated. The objective of this study is to evaluate the prevalence of dyslexia in an unselected school population using clearly defined and rigorous diagnostic criteria and methods.
Cross sectional study. We selected a random cluster sample of 94 fourth grade elementary school classes of Friuli Venezia Giulia, a Region of North Eastern Italy. We carried out three consecutive levels of screening: the first two at school and the last at the Neuropsychiatry Unit of a third level Mother and Child Hospital. The main outcome measure was the prevalence of dyslexia, defined as the number of children positive to the third level of screening divided by the total number of children enrolled.
We recruited 1774 children aged 8-10 years, of which 1528 received parents' consent to participate. After applying exclusion criteria, 1357 pupils constituted the final working sample. The prevalence of dyslexia in the enrolled population ranged from 3.1% (95% CI 2.2-4.1%) to 3.2% (95% CI 2.4-4.3%) depending on different criteria adopted. In two out of three children with dyslexia the disorder had not been previously diagnosed.
This study shows that dyslexia is largely underestimated in Italy and underlines the need for reliable information on prevalence, in order to better allocate resources both to Health Services and Schools.
尽管阅读障碍是影响儿童的最常见神经行为障碍之一，但流行率不确定，可用数据稀少且陈旧。本研究的目的是使用明确界定和严格的诊断标准和方法，评估未选择的学校人群中阅读障碍的流行率。
横断面研究。我们选择了意大利东北部弗留利-威尼斯朱利亚大区的 94 个四年级小学班级的随机聚类样本。我们进行了连续三个级别的筛选：前两个在学校进行，最后一个在三级母婴医院的神经精神病学部门进行。主要观察指标为阅读障碍的流行率，定义为通过三级筛选的儿童数量除以入学儿童总数。
我们招募了 1774 名 8-10 岁的儿童，其中 1528 名儿童的家长同意参与。在应用排除标准后，1357 名学生构成了最终的工作样本。在登记人口中，阅读障碍的流行率范围为 3.1%（95%CI 2.2-4.1%）至 3.2%（95%CI 2.4-4.3%），具体取决于采用的不同标准。在有阅读障碍的儿童中，有两成的儿童以前未被诊断出该疾病。
本研究表明，意大利对阅读障碍的认识严重不足，并强调需要可靠的流行率信息，以便更好地为卫生服务和学校分配资源。
