Dr Alison Stephen Population Nutrition Research MRC Human Nutrition Research Cambridge, UK NATIONAL DIET AND NUTRITION SURVEY ROLLING PROGRAMME Report of the Comparison Study
NDNS - Background Previous NDNS surveys: Children aged y - fieldwork OPCS, DNU. Dental: Birmingham, Newcastle People aged 65 + y - fieldwork SCPR, DNU. Dental: UCL Young people aged 4-18 years - fieldwork 1997 ONS, HNR. Dental: Birmingham, Newcastle Adults aged years - fieldwork ONS, HNR.
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
NDNS ConsortiumNatCen NDNS office - London Operations – Brentwood NISRA Interviewers & Nurses 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
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
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
Responsibilities – UCL Survey doctor Physical activity Oral health questions
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
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)
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
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
NDNS Comparison Study Table 4B Breakdown of CU-level response rates Outcome24-hour recallDiaryAll N%N%N% ISSUED ADDRESSES Ineligible Eligible ELIGIBLE Cus Total unproductive: Non-contact Refused Other reason Partially productive CUs(<3 dietary days for all respondents) Fully productive CUs (3+ dietary days for at least one respondent)
NDNS Comparison Study Summary 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
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
NDNS Comparison study Tables 7A and7B -Energy intake and expenditure (DLW) for recall and diary - Males Each cell n =8
NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary - Females Each cell n =8
NDNS Comparison study Tables 7A and7B - Energy intake and expenditure (DLW) for recall and diary Each cell n =8 Males Females
NDNS Comparison study Table 7D - % Under, adequate and over reporting - Males Each cell n =8
NDNS Comparison study Table 7D - % Under, adequate and over reporting - Females Each cell n =8
NDNS Comparison study Table 7D - % Under, adequate and over reporting - Each cell n =8 Males Females
NDNS Comparison Study Summary of energy intake and misreporting there were few differences in energy intake for the two methods. Only in men aged 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
24 h recallDiaryPrevious NDNS* MFMFMF n Protein g Fat g Carbohydrate g Total sugars g NMES g NSP g Calcium mg Iron mg Folate µg Vitamin C mg NDNS Comparison study Nutrient intakes – young people 4-18 years * 1997
24 h recallDiaryPrevious NDNS* MFMFMF n Protein g Fat g Carbohydrate g Total sugars g NMES g NSP g Calcium mg Iron mg Folate µg Vitamin C mg NDNS Comparison study Nutrient intakes – adults years * 2000/01
24 h recallDiaryPrevious NDNS MFMFMF n Protein g Fat g Carbohydrate g Total sugars g NMES g NSP g Calcium mg Iron mg Folate µg Vitamin C mg NDNS Comparison study Nutrient intakes – older adults 65+ years * 1994/5
24 h recallDiaryPrevious NDNS MFMFMF n Protein % energy Fat % energy Carbohydrate % energy Total sugars % energy NMES % energy NDNS Comparison study Nutrient intakes as % energy– young people 4-18 years
24 h recallDiaryPrevious NDNS MFMFMF n Protein % energy Fat % energy Carbohydrate % energy Total sugars % energy NMES % energy NDNS Comparison study Nutrient intakes as % energy – adults years
24 h recallDiaryPrevious NDNS MFMFMF n Protein % energy Fat % energy Carbohydrate % energy Total sugars % energy NMES % energy NDNS Comparison study Nutrient intakes as % energy – adults 65+ years
NDNS Comparison Study Summary 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 ( ), young people (1997) and adults ( ).
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) 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. 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
Generating Dietary Feedback Letters Recalls/Diaries editing & coding complete Emily & Rachel: New food nutrient composition data entry Darren: input info on feedback requested & respondent identifiers Data output Data checking Individual feedback lettersGraphs Feedback Checking Feedback letter transfer to NatCen Darren Darren/Gemma Celia Adrian/Mark/Gemma Birgit Zoe NDNS Comparison Study 2007
Question Yes %No %Not answ % 1. Do you think that the graphs showing your results compared with UK guidelines for the population are easy to understand? Do you think comparing your results with UK guidelines is useful? Is there any other information about your diet you would like to receive? Would you be interested in a web page for NDNS participants that lists more information about the survey (for example results as they emerge), updates on what the nation consumes and nutrition information and advice? A %B %Not answ % 4. Some additional information we could provide would take longer to produce e.g. No. of portions of fruit and vegetable you consume. A)I would like to receive more information about my diet even if I have to wait up to 12 months to receive it. B)B) I am happy with the information provided which I receive within 3 months after completion of the dietary assessment Table 5B Response to feedback questionnaire
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, cant 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.
Contributors to writing the Comparison Study report HNR Alison Stephen Birgit Teucher Les Bluck Darren Cole Emily Fitt Adrian Mander Rachel Woodward Anthony Wright Nat Cen Beverley Bates Caireen Roberts Helen Mackenzie Claire Deverill UCL Jenny Mindell