ARCHIVE DOCUMENTATION STUDY NO: 4243 STUDY TITLE: National Diet and Nutrition Survey: Young People Aged 4-18 Years, 1997 Validation and conversion: -------------------------- DATA All SPSS .exp and .sav files were converted to .por files by the Archive during processing of the study, for users' convenience. Some filename changes resulted from this - see table below. Files 'sugars1.por' and 'vit25.por' - codes for missing values were added to this file during processing - all other files had missing values set by depositor. Some variables in most files are unlabelled, but descriptions of the variables may be found in the documentation, although there is no comprehensive list. Nutrient Databank ----------------- In July 2001, the MAFF nutrient databank, used to convert food weights into nutrient intake was supplied by the depositor and added to this study. It is available in Excel, CSV, SPSS portable, and on request, .ntx and .dbf formats. The depositor has indicated that the Excel version is the most 'user-friendly' format. Relevant parts of the User Guide for the nutrient databank include: *Section 4: Figure 4.22 - details of nutrients measured and units: identifies the 55 nutrients by variable name. *Appendix F: Food code list - gives detailed description of food codes *Appendix G: Food types and food groups. DOCUMENTATION Word files sent by the depositor were converted to Adobe Acrobat .pdf format and compiled into 4-volume User Guide, and bookmarks added for ease of navigation. Summary of value-added outputs: ------------------------------- See above. Constraints on the reliability and/or usability of the data: ------------------------------------------------------------ Most variables and values are labelled, but some derived variables are not. These may be found in the documentation - see sections and tables on SPSS and SIR data, though there is no comprehensive variable list in the User Guide. Some filenames vary from those given in the documentation - see section on filename changes below. The Stata version of this study is in Stata 8 SE format, as some files have more than 2,047 variables. The larger files will therefore not open in Stata 6, 7 or 8 (standard) versions. File name changes: ------------------ Some names of the files deposited vary from those in the documentation. In addition, some names have been changed during data processing. Details are as follows: Files deposited with different names ------------------------------------ In Fig 4.12 (Volume 1, page 171 in the User Guide), dietary data files 'fats' and 'sugars' referred to in the table are in fact split into more than one file - 'fats1' and fats2', and 'sugars1', 'sugars2' and 'sugars3'. Please note - the file 'vitreq.por' is not listed under Fig 4.12, but was sent by the depositor with the other vitamin files - this file contains retinol and retinol equivalent variables as noted elsewhere in the documentation. Filenames changed during processing ----------------------------------- 1. All SPSS files deposited as .exp files have been converted to .por files, for ease of use between computing systems. Therefore, where the documentation refers to .exp, the file extension will be .por. 2. In addition, some derived variable files were deposited as SPSS .sav files. Again, these were converted to .por files. In most cases, this just results in a change from .sav to .por, but some filenames have had to be changed further to distinguish them from the corresponding .exp/.por files, but are referred to by their original names in the documentation. The table below provides further details: Derived Variables -------------------------------------- |ORIGINAL FILENAME | NEW FILENAME | |-------------------|----------------| |Schedule.sav | schedule.por | |-------------------|----------------| |Smoke.sav | smokeder.por | |-------------------|----------------| |Frequency.sav | frequency.por | |-------------------|----------------| |Hbox.sav | household.por | |-------------------|----------------| |Pickup.sav | pickupder.por | |-------------------|----------------| |Measure.sav | measure.por | |-------------------|----------------| |Blood.sav | blood.por | |-------------------|----------------| |PAct.sav | pactder.por | -------------------------------------- SIR Users --------- Users of the SIR data for this study may also need the files in the above table depending on the sort of analysis to be undertaken. On advice from ONS, the UK Data Archive will also send these files with each order for the SIR version of this study, so that they are available should they be needed. SPSS Users ---------- The documentation clearly states that the SPSS files include the same variables as the SIR files (Section 4.1), but in response to a user query, it is apparent that they do not contain the 'plate' level data (SIR record 3). Therefore SPSS portable files have been generated from the SIR database for each of the 32 SIR record types noted in the documentation. These files are named after the SIR record they contain, except in the case of files 'bloodsir.por' (blood record) and 'nutrientsir.por' (nutrient record), where 'sir' has been added to the filename to distinguish them from the SPSS files deposited as 'blood' and 'nutrient'. SIR Record No. SPSS file ---------- --------- 1 cndmainq.por 2 day.por 3 plate.por 4 fooditem.por 5 food1.por 6 food2.por 7 food3.por 8 hojob.por 9 majob.por 10 ypjob.por 11 yeduc.por 12 self.por 13 follw.por 14 cno.por 15 anthb.por 16 yindiv.por 17 drink.por 18 bloodsir.por 19 cnoexamq.por 21 ypersdv1.por 27 agedvs.por 28 weight.por 30 cndpactq.por 31 pact1.por 32 pact2.por 33 pact3.por 34 pact4.por 35 pact5.por 36 pact6.por 37 pact7.por 40 nutrientsir.por 41 fdsource.por As with the other SPSS files, some of the variables in these files have missing labels, but these can be deduced from the documentation. The 'lunch' variables in files 'pact1.por' to 'pact7.por' have some unlabelled codes of '6' throughout, but values are otherwise labelled. Technical report recommended/essential: --------------------------------------- It is strongly recommended that users purchase the technical report for this study, even though the User Guide is quite comprehensive. Details are as follows: Gregory J. et al (2000) "National Diet and Nutrition Survey: young people aged 4 to 18 years, volume 1: report of the Diet and Nutrition survey", London: TSO. Walker A. (2000) "National Diet and Nutrition Survey: Young people aged 4 to 18 years, volume 2: report of the Oral Health Survey", London: TSO.