Standardised coding of diet records: experiences from INTERMAP UK.


Journal Article

Coding diet records is a basic element of most dietary surveys, yet it often receives little attention even though errors in coding can lead to flawed study results. In the INTERnational study of MAcro- and micronutrients and blood Pressure (INTERMAP study), efforts were made to minimise errors in coding the 18, 720 diet records. Staff were centrally trained and certified before being able to process study data and ongoing quality control checks were performed. This involved the senior (site) nutritionist re-coding randomly selected diet records. To facilitate standardisation of coding in the UK, a code book was designed; it included information about coding brand items, density and portion size information, and default codes to be assigned when limited information was available for food items. It was found that trainees, despite previous experience in coding elsewhere, made coding errors that resulted in errors in estimates of daily energy and nutrient intakes. As training proceeded, the number of errors decreased. Compilation of the code book was labour-intensive, as information from food manufacturers and retailers had to be collected. Strategies are required to avoid repetition of this effort by other research groups. While the methods used in INTERMAP to reduce coding errors were time consuming, the experiences suggest that such errors are important and that they can be reduced.

Full Text

Cited Authors

  • Conway, R; Robertson, C; Dennis, B; Stamler, J; Elliott, P; INTERMAP Research Group,

Published Date

  • May 2004

Published In

Volume / Issue

  • 91 / 5

Start / End Page

  • 765 - 771

PubMed ID

  • 15152639

Pubmed Central ID

  • 15152639

Electronic International Standard Serial Number (EISSN)

  • 1475-2662

International Standard Serial Number (ISSN)

  • 0007-1145

Digital Object Identifier (DOI)

  • 10.1079/BJN20041095


  • eng