The NCMP dataset is a sample and the prevalence figures in this report are estimates assumed to apply to the entire population. These estimates are subject to natural random variation.
Confidence intervals are quoted in the publication and included in the tables to indicate this variation.
Comparisons between groups and over time have been statistically tested to determine whether differences are likely to be genuine (i.e. statistically significant) or the result of random natural variation. Only statistically significant differences have been described with terms such as “higher”, “lower”, “increase” or “decrease”. When a comparison does not show a statistically significant difference, this will be described using terms such as “similar to” or “the same as".
In the statistical publication text and excel tables, percentages are usually shown to one decimal place. The excel tables contain more decimal places. Differences are calculated from the unrounded figures in the excel tables and then shown to one decimal place in the text.
Disclosure control rules for NCMP outputs were revised for the 2019/20 publication and details are in the disclosure control methodology change notice.
Disclosure control was not required for the 2021/22 data in this publication as data was only published at a national level.
The report is accompanied by:
- Data tables and data quality tables, including 95 per cent confidence intervals which should be considered when interpreting results.
- Methodology and Data Quality section and technical appendices with information on data collection, validation, confidence intervals, statistical testing and the methodologies used for BMI classification rates and for statistical weighting.
