Before children start elementary school, doctors and nurses from the Ministry of Education conduct a health screening. According to a survey conducted in 2000–2001 based on a sample of 30,000 students examined in this way, 14% of 6-year-olds are overweight, including 4% who are obese and 10% who are moderately overweight. Children in large urban areas and priority education zones (ZEPs) are more frequently overweight than those living in rural communities. One in five students has a vision impairment, with a screening deficit that appears more pronounced in ZEPs. Oral health also appears to be poorer among students in these areas. Asthma affects between 6% and 12% of children to varying degrees of severity, with a higher prevalence among boys, while MMR vaccination coverage remains close to 90%. Finally, the prevalence of language disorders and delays appears to be higher among boys and among students attending schools in ZEPs.