About this Resource

Linking and Mapping Postcoded Longitudinal Dietary Survey Data

Researcher	Researcher D
Discipline	Geography
Outputs	Mapping postcoded data from the ASH30 longitudinal dietary survey and linking it to Health Survey for England (HSE) data
Study area	UK
Geographical units	Postcode; region; GOR
Time period	1980 and 2000
Reference datasets	NSPD
	Summary
Main tasks	Researcher D wanted to map postcoded dietary data from 1980 and 2000 from the ASH30 survey and also to link this data to data from the Health Survey for England (HSE). The researcher had already done a lot of pre-processing of his postcoded data. He had taken each postcode from the 1980 and 2000 surveys and matched those to the equivalent (2006) postcode. He had also checked that his postcodes were correctly formatted. He was then able to use GeoConvert to obtain grid references (coordinates) for each postcode as well as the government office region (GOR) within which each postcode was located. Using these grid references, the researcher was able to use ArcGIS to map the postcodes as a set of points. Using the region codes, he could link his data to HSE data to carry out further analysis.
	Hints, Tips and References
Hints & Tips	In this case, Researcher D had already matched his 1980 and 2000 postcodes to an equivalent 2006 postcode location. An alternative (and probably quicker) way of obtaining the relevant postcode locations would have been to download the 1980 and 2000 postcode directories from UKBORDERS and to then use Access or similar software to extract the relevant fields from the directories. Note that earlier versions of the postcode directories are both less accurate and less precise than later versions
References	ASH30 - Lake A, Rugg-Gunn A, Hyland R, Wood C, Mathers J and Adamson A (2004) Longitudinal dietary change from adolescence to adulthood: perceptions, attributions and evidence, Appetite, 42, 255-263.
	GeoConvert - http://geoconvert.mimas.ac.uk
	Health Survey for England - http://www.esds.ac.uk/government/hse/