Scottish Government

Title

Children of healthy weight.

Associated Targets

Reduce the rate of increase in the proportion of children with their Body Mass Index outwith a healthy range by 2018.

Brief Description

The proportion of children aged 2-15 years whose Body Mass Index lies within a healthy range (between the 5 th and 85 th percentile of the UK growth reference charts).

Strategic Objective(s) to Which Indicator Relates

This indicator informs progress in relation to the Healthier Strategic Objective.

More Detailed Definitions

Definitions of Keywords

BMI is calculated by dividing weight in kilograms by height in metres squared.

Definitions of healthy weight for children are currently based on the 1990 UK growth reference charts.

Evidence Source

Data source: Scottish Health Survey

This is an important high level indicator that encompasses various aspects of lifestyle and wellbeing.

Baseline and Past Trends

Baseline, most recent value available when target was set (average annual change 1998 to 2003): 1.7% (3.0% boys; 0.2% girls)

Previous value: No previous value available. 1998 was the first time this data was collected so there are no figures on the average annual change prior to 1998.

Data for 2008 onwards available in Scottish Health Survey annual reports and on Scotland Performs (from September 2009).

Methodology for Data Source

Sample survey data.

Healthy weight of children is defined using the UK standard growth reference curves (Cole TJ et al, 1995).

The method used corrects for the skewed distribution of BMI values and then assigns each child's BMI to a centile using an age-sex specific lookup of values from the standard reference curves.

Children having a BMI that lies between the 5 th and 85 th percentile of the reference data are of healthy weight.

The indicator is based on the annual change in the proportion of children whose BMI is outwith the healthy range. Data are measured annually from 2008 onwards and therefore from 2009 onwards the indicator is based on the change since the previous year. For periods prior to this when the survey was run less frequently, the indicator is based on the annual average change since the last survey i.e. for 2003 the annual average change between 1998 and 2003 is used and for 2008 the annual average changed between 2003 and 2008 is used.

The denominator population for the Scottish Health Survey 2003 was around 3,000 children aged 2-15 years; from 2008 onwards the annual denominator is approximately 2,000 children aged 2-15 years.

Data Ownership and Quality Assurance

Past data were not National Statistics, but data for 2008 onwards are National Statistics.

Publication of Data

Annual reports to be published by the Scottish Government in September of each year. (September 2009 report relates to 2008 survey data)

Methodology for Recent Change Arrow on Scotland

If the latest annual percentage change is more than 0.5 percentage point higher than the previous year's annual percentage change the arrow will be "performance worsening". If the latest annual percentage change is more than 0.5 percentage point lower than the previous year's annual percentage change the arrow will be "performance improving". If the latest annual percentage change is within 0.5 percentage point of the previous year's annual percentage change, the arrow will be "performance maintaining". The threshold of 0.5 percentage point chosen is based on an assessment of the data available at this time, and may need to be reviewed as more information becomes available in the future.