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National Statistics
Publication, Part of

National Child Measurement Programme, England 2018/19 School Year [NS]

Official statistics, National statistics
Publication Date:
Geographic Coverage:
Geographical Granularity:
Regions, Local Authorities

Data Quality

Data Quality - Coverage

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).  

The overall national rate has increased from 80% in 2006/07 to 95% in 2018/19.

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.

Chart showing participation rate for reception and year 6 over time



Data Quality – Missing and imprecise data

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 and eight LAs had more than 25% of records without an ethnicity code.

Chart showing the proportion of missing ethnicity codes, NHS numbers and postcodes over time


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 nationally 17% of heights were whole numbers in 2018/19. This was over 30% for two LAs.

Chart showing the proportion of whole number heights and weights over time



Data Quality – Timeliness

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 2018-19 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.

Last edited: 7 October 2019 1:42 pm