School-based measurement of children's Body Mass Index

Background, purpose and significance:

With increases in childhood obesity, school-based measurement of children's body mass index (BMI) has increased as a surveillance and screening tool. However, little is known about the extent to which states and school districts have adopted BMI screening policies to what extent they are implemented.

Method:

Data from a nationally-representative sample of US public elementary schools and school districts were used to evaluate linkages between state laws, district policies, and school practices, gathered for the 2006-7 school year.

Results:

Eleven states had enacted BMI-related laws as of the study reference date. Additionally, wellness policies collected from 529 districts within 47 states indicated that 16% of districts recommended or required student BMI measurement, either with or without parental reporting. Districts were more likely to have policies where required by the state (52.4% vs. 29.0%, p < .001). In our sample of 578 public elementary schools, 45% of schools reported doing some form of BMI measurement, either annually or for selected grades, and 25% reported sending student BMI information to parents. Schools in states requiring BMI monitoring were not more likely to have school-based BMI measurement than schools in states with no such laws; however, school BMI activities were more common where district policy recommended/required it (67.4% vs. 39.6%, p < .001).

Conclusions:

BMI measurement is more likely when included in district policy. Future studies are needed to examine the multi-level relationships and to evaluate these relationships in the context of school, district, and other state level factors.