We sought to: (i) estimate the prevalence of significant cognitive delay (a marked delay in the development of general cognitive functioning) among nationally representative samples of young children in middle- and low-income countries; (ii) estimate the total number of children under 5 years of age with significant cognitive delay living in low- and middle-income countries; and (iii) estimate the potential impact of five preventative interventions.

中文翻译：

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低收入和中等收入国家3至4岁儿童的重大认知迟缓：患病率估计数和预防干预措施的潜在影响

我们试图：（i）估计在全国代表性的中低收入国家幼儿样本中，重大认知延迟（普遍认知功能发展的显着延迟）的发生率；（ii）估计生活在低收入和中等收入国家的5岁以下认知严重延迟的儿童总数；（iii）估计五种预防性干预措施的潜在影响。