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Dr Alison Stephen Population Nutrition Research MRC Human Nutrition Research Cambridge, UK

NATIONAL DIET AND NUTRITION SURVEY ROLLING PROGRAMME Report of the Comparison Study. Dr Alison Stephen Population Nutrition Research MRC Human Nutrition Research Cambridge, UK. NDNS - Background. Previous NDNS surveys: Children aged 1.5 - 4.5 y - fieldwork 1992-3

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Dr Alison Stephen Population Nutrition Research MRC Human Nutrition Research Cambridge, UK

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  1. NATIONAL DIET AND NUTRITION SURVEY ROLLING PROGRAMME Report of the Comparison Study Dr Alison Stephen Population Nutrition Research MRC Human Nutrition Research Cambridge, UK

  2. NDNS - Background • Previous NDNS surveys: • Children aged 1.5 - 4.5 y - fieldwork 1992-3 • OPCS, DNU. Dental: Birmingham, Newcastle • People aged 65 + y - fieldwork 1994-5 • SCPR, DNU. Dental: UCL • Young people aged 4-18 years - fieldwork 1997 • ONS, HNR. Dental: Birmingham, Newcastle • Adults aged 19-64 years - fieldwork 2000-1 • ONS, HNR.

  3. NDNS - Review • Following review of dietary survey programme in 2002/03, FSA Board agreed to rolling programme model for future NDNS. • Survey will run continuously with fieldwork carried out every year • Generate data more rapidly • Track changes over time more easily • Collect additional data at short notice • More responsive to policy needs

  4. NatCen • NDNS office - London • Operations – Brentwood • NISRA • Interviewers & Nurses NDNS Consortium HNR • NDNS office • Field lab coordination • Bioanalysis/NBL • DLW • Dietary Assessment • Sun exposure • Data Management • UCL • Survey Doctor • Physical Activity • Service Agreements • Addenbrookes • Aberystwyth University • Field Laboratories

  5. Responsibilities – Nat Cen • General management issues • Sampling • Fieldwork • Interviews – self complete, CAPI • Dietary assessment • Physical measurement protocols & equipment (H & W, WH, MUAC, demi-span, infant length, BP) • Physical activity - Questionnaires, Actigraph • Blood and urine collections • Administration of DLW • Briefings • Liaison with NISRA • Reports - Monthly reports to FSA, response rate, main reports

  6. Responsibilities - HNR • Dietary assessment • Diet coding and editing – queries, new foods etc • Nutrient databank • Dietary data entry and analysis computer system • Dietary feedback forms for respondents • Blood and urine analysis • Recruitment of local processing labs, training • Ethics arrangements for processing laboratories • Supplies for collection and all analyses • Analysis of blood and 24h urine samples • Storage of unused blood for 10 years • Doubly labelled water • Production of samples for field • Receipt and analysis of urine • Data analysis and report writing: dietary data, blood and urine, DLW

  7. Responsibilities – UCL • Survey doctor • Physical activity • Oral health questions

  8. NDNS - management • Project Board • Chaired by FSA, with representatives from all 4 countries • Department of Health • External advisors: Sheila Bingham, Hilary Powers • Senior representatives of Nat Cen, HNR and UCL • Meets 4-6 times per year • NDNS Management Team • Chaired by Nat Cen • Representatives of Nat Cen, HNR and UCL – some invitees depending on agenda items • Meet 2-3 times per year • HNR management team • Key members of HNR NDNS team – meets every 2-3 months

  9. NDNS –main elements • Comparison Study • Jan 07– Feb 08 (fieldwork March – July 2007) • Sampling 1840 – final number 1049, 160 DLW, reasonably nationally representative (no NI) • Run-in • Feb- March 2008 • N = 5 points/month, 10 DLW, blood, urine • Main stage • April to March each year • 10 points/month • Interview/Dietary assessment: Core (1000), Scot (boost to 400/y), NI (boost to 200/y) • Blood: Core, Scot, NI • Urine: Core, Scot, NI • DLW: Core (160)

  10. Aims of the Comparison Study • compare response rates for 4-day unweighed diary and 4 interviewer-administered 24 hour recalls • compare quality of data and degree of under-reporting achieved • test a new physical activity questionnaire • investigate feasibility of physical activity monitors for children • validate the new physical activity questionnaire against an objective measure of energy expenditure • test questions on food consumption and social and domestic circumstances affecting consumption • investigate feasibility of obtaining more detailed information on food packaging • investigate feasibility of sun exposure questionnaire

  11. Aims of the Comparison Study • compare response rates for 4-day unweighed diary and 4 interviewer-administered 24 hour recalls • compare quality of data and degree of under-reporting achieved • test a new physical activity questionnaire • investigate feasibility of physical activity monitors for children • validate the new physical activity questionnaire against an objective measure of energy expenditure • test questions on food consumption and social and domestic circumstances affecting consumption • investigate feasibility of obtaining more detailed information on food packaging

  12. Outcome 24-hour recall Diary All N % N % N % ISSUED ADDRESSES 920 920 1840 Ineligible 130 14 109 12 239 13 Eligible 790 86 811 88 1601 87 ELIGIBLE Cus Total unproductive: 379 48 375 46 754 47 Non-contact 12 2 14 2 26 2 Refused 309 39 299 37 608 38 Other reason 58 7 62 8 120 7 Partially productive CUs(<3 dietary days for all respondents) 27 3 13 2 40 2 Fully productive CUs (3+ dietary days for at least one respondent) 384 49 423 52 807 50 NDNS Comparison StudyTable 4B Breakdown of CU-level response rates

  13. NDNS Comparison StudySummary of interviewer and coder feedback • both dietary assessment methods presented some challenges in the field for interviewers and respondents • one of the main determinants of the chosen method was the need to include two weekend days in the dietary assessment period, which was more difficult to achieve for recall for both interviewers and respondents

  14. NDNS Comparison study Energy intake by 24h recall and estimated diary n 14,14 9,26 16,13 23,22 36,39 52,51 44,53 38,37 12,16 14,14 14,11, 13,20 44,51 63,81 60,60 52,55

  15. NDNS Comparison study Tables 7A and7B -Energy intake and expenditure (DLW) for recall and diary - Males Each cell n =8

  16. NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary - Females Each cell n =8

  17. NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary Females Males Each cell n =8

  18. NDNS Comparison study Table 7D - % Under, adequate and over reporting - Males Each cell n =8

  19. NDNS Comparison study Table 7D - % Under, adequate and over reporting - Females Each cell n =8

  20. NDNS Comparison study Table 7D - % Under, adequate and over reporting - Females Males Each cell n =8

  21. NDNS Comparison StudySummary of energy intake and misreporting • there were few differences in energy intake for the two methods. Only in men aged 35-49 years was there a difference, with energy intake for diary lower than for 24h recall • there were few differences in misreporting between methods. Both methods had substantial under-reporting, but not in any consistent direction • there appeared to be slightly more over-reporting with 24h recall in young children than diary

  22. NDNS Comparison study Nutrient intakes – young people 4-18 years * 1997

  23. NDNS Comparison study Nutrient intakes – adults 19-64 years * 2000/01

  24. NDNS Comparison study Nutrient intakes – older adults 65+ years * 1994/5

  25. NDNS Comparison study Nutrient intakes as % energy– young people 4-18 years

  26. NDNS Comparison study Nutrient intakes as % energy – adults 19-64 years

  27. NDNS Comparison study Nutrient intakes as % energy – adults 65+ years

  28. NDNS Comparison StudySummary of nutrient intake • there were no substantial differences in nutrient intake by method • carbohydrate • fat • protein • total sugars • non-milk extrinsic sugars (NMES) • non-starch polysaccharide (NSP) • calcium • iron • folate • vitamin C • results were similar to past NDNS surveys: older people (1994-95), young people (1997) and adults (2000-01).

  29. NDNS Comparison study Dietary feedback • Respondents were offered feedback on their diet & 84% did request feedback • Challenges • High throughput requires an automated letter • Contents • Informative • Not too lengthy • Easy to understand • Limited by time available to produce outputs • Feedback questionnaire to evaluate the success of the dietary feedback letters • Key Nutrients Reported • Fat intake as % of total energy • Saturated fat intake as % total energy • NMES • Dietary fibre • Vitamin C • Folate • Calcium • Iron • Energy intake (Kcal/d)

  30. To assist with the maintenance of a healthy body weight and reduce the risk of chronic diseases such as heart disease, UK guidelines state that fat should only make up 33% or less of total energy. NDNS Comparison study Dietary feedback Fat intake is expressed as a % of total energy consumed. Some fat is essential in the diet but children and adults tend to eat too much in the UK.

  31. Individual feedback letters Graphs Darren: input info on feedback requested & respondent identifiers Recalls/Diaries editing & coding “complete” Emily & Rachel: New food nutrient composition data entry Generating Dietary Feedback Letters Data output Darren Celia Data checking Adrian/Mark/Gemma Darren/Gemma Feedback Checking Birgit Zoe Feedback letter transfer to NatCen NDNS Comparison Study 2007

  32. Table 5B Response to feedback questionnaire

  33. Feedback questionnaire: some respondent comments • “I am concerned at the unrealistic accuracy implied by some of your analysis, eg my folate intake was reported as 381µg/d. Can you really make assessments to 3 figures on the basis of a few days data – NO!!” • “I cannot see how this survey is of any use and seems to me to be rather a waste of time and money especially after the depth of detail concerning diet that is needed.” • “I am over 80 years of age, can’t I have more information in less than 12 months?” • “I was very impressed with the information returned and am very appreciative of the extra time put in to produce this feedback. Thanks.”

  34. Nat Cen • Beverley Bates • Caireen Roberts • Helen Mackenzie • Claire Deverill • UCL • Jenny Mindell Contributors to writing the Comparison Study report HNR • Alison Stephen • Birgit Teucher • Les Bluck • Darren Cole • Emily Fitt • Adrian Mander • Rachel Woodward • Anthony Wright

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