National Child Measurement Programme, England, 2021/22 school year

The participation rate is the percentage of children who have been measured in mainstream state-maintained schools out of those eligible for measurement (this excludes children who could not be measured due to physical or mental impairment).  Note: participation rate data was not collected or published in 2019/20 and 2020/21 due to the impact of the Covid-19 pandemic on these collection years.

The overall national rate has increased from 80% in 2006/07 to 92% in 2021/22.

The participation rate can affect the accuracy of estimates derived from the data.  For example, if the participation rate is very low in a local authority, then the prevalence estimates for the BMI categories should be treated with caution as those children measured may not be representative of all children in the LA. See annex B of the appendices for more detail.

Missing data

The proportion of missing data items has improved over time although it still remains quite high for NHS number and ethnicity.

24 LAs had over 25% of records with missing NHS numbers, eight LAs had more than 15% of records without an ethnicity code.

Imprecise data

By chance, 10% of height and weight measurements would be expected to be whole numbers. However, there is some evidence of LAs rounding heights to whole numbers as 19 LAs had over 20% of their heights being whole numbers and nationally 16% of heights were whole numbers in 2021/22.

The NCMP data collection system has a data quality checks incorporated into it, so that local authorities can check and correct their submitted data for unexpected issues. These are presented as a number of data quality indicators. In 2021/22 all LAs signed off their data quality indicators.

Table 8 shows the data quality indicators by submitting local authority with breaching indicators highlighted in red and breach reasons as provided by the LA on submission (if applicable).

For more information: See Table 8: Data quality indicators for the NCMP collection by submitting local authority.