Review of Approaches to Measuring Food Consumption for Food-based Micronutrient Programming

Transcription

1 Review of Approaches to Measuring Food Consumption for Food-based Micronutrient Programming Jennifer Coates, Brooke Colaiezzi, James Wirth, Jack Fiedler, Bea Rogers MAD Group Food Consumption Measurement Workshop April 14-15, 2011

2 Background and Justification MN programs lack food consumption (FC) data to tailor solutions to context-specific problems. The trade-offs and implications of the choice of FC Method (FCM) are not always understood. Choice of (FCM) varies by program info needs, data availability, degree of precision required, and resource considerations. Comparative analysis needed

3 Objectives and Approach 1. Describe typical uses and resource requirements of FCM for decision-making throughout the MN program cycle. 1. Analyze strengths and weaknesses of FCM for information needs and resource requirements. 2. Identify potential improvements and complementarities

4 Food Consumption Measurement Approaches Hour Recall 2. Food Frequency Questionnaires 3. Fortification Rapid Assessment Tool 4. Household Income and Expenditure Surveys 5. Food Balance Sheets and Industry Data Other approaches not discussed in this review 3-day weighed record 3-day food diary Direct observation Other dietary questionnaires (e.g., child feeding, complementary feeding, breastfeeding)

5 Assessment The Program Cycle Identify and prioritize needs Define project goals and objectives Select appropriate interventions Develop detailed implementation plan Evaluate program impact Modify design where necessary Monitor program Analysis Implement activities 5 Action

6 Program Design Questions 1. Which micronutrients should be provided? What micronutrient deficiencies of public health importance exist? At what levels of severity and prevalence? What is the relationship of deficiency to inadequate intake? How is the problem distributed in the population?

7 Program Design Questions, Cont d 2. Which food(s) should be fortified? What foods are consumed regularly by large proportions of the population? What proportion of is obtained through the purchase of centrally processed foods? What proportion of the population purchasing these foods has inadequate intake of a micronutrient that can be added to this food vehicle?

8 Program Design Questions, Cont d 3. What should the fortification level be? What is the nutrient intake gap? What quantities of the potential food vehicle are being consumed? What is the geographic distribution of the intake gap and of consumption of the food vehicle?

9 Monitoring Questions Reach? Coverage? Effective coverage? Excessive coverage?

10 Impact Evaluation Questions What proportion of the population and target population have achieved significant improvements in micronutrient intake, and reductions in micronutrient deficiency? What proportion of this change can be attributed to the micronutrient intervention?

11 Food Consumption Measurement Approaches: Overview, Strengths, and Weaknesses

12 24-Hour Recall: Overview Individual-level survey Provides comprehensive data on type and quantity of foods consumed over previous 24 hours Estimate of individual macro- and MN intakes versus requirements (adequacy) WHO recommends they be used for the design of fortification programs

13 24-Hour Recall: Strengths Offers a high degree of precision relative to other methods Quantitative estimates All foods included that the respondent can recall (eaten inside and outside home, not limited to checklist) Calculated at the individual rather than the Hh level Takes into account preparation methods and their effect on estimated nutrient content

14 24-Hour Recall: Weaknesses High resource requirements Expensive, significant training requirements, and databases (e.g., food composition tables) often need to be updated Limited generalizability Usually conducted on a small sub-sample of target population due to cost considerations Often not representative at national or sub-national/regional level A single 24-hr recall will not capture intra-individual variation in daily consumption patters or seasonal variation

15 Food Frequency Questionnaires: Most common dietary assessment tool for large epi studies of diet and health Overview Frequency of consumption of a pre-specified list of food items Sometimes portion size (semi-quantitative FFQ) Recall period ranges on average 7-30 days

16 FFQ: Strengths Good at characterizing the usual dietary patterns with a longer recall period The data are easier and less time-consuming to collect than 24-hour recall Useful for assessing suitable vehicles and fortificant levels as list can be tailored to include all significant sources of a MN Useful for monitoring reach, coverage, effective coverage, as list can specify brand names of fortified foods

17 FFQ: Weaknesses Does not provide a precise quantitative measure of consumption. Can require substantial up-front investment to develop and test FFQ instrument.

18 Fortification Rapid Assessment Tool: Overview Designed to assist in selecting an appropriate vehicle for fortification, and in setting appropriate and safe fortificant levels. Originally developed in 1990 s by Healthbridge (formerly Path-Canada) under contract to MI. Simplified food frequency and 24 hour recall focuses on pre-identified potentially fortifiable foods

19 FRAT: Strengths Can be tailored to specific program needs. Assesses individual-level consumption of certain foods by key target population groupsuseful for selecting vehicles. Asks about past 24 hours and past 7 days of consumption to estimate usual intake. Collects additional data to complement the consumption information

20 FRAT: Weaknesses Only asks about intake of potential food vehicles, therefore the FRAT does not capture an individual s total nutrient gap. Without nutrient gap information, it is less useful for setting fortification levels. The method has been field-tested but not validated

21 Household Income and Expenditure National level income and expenditure surveys to estimate household apparent consumption Conducted every 2-5 years in most countries Surveys: Overview Typically captures food source and quantity Recall period is between one week and 30 days.

22 HIES: Strengths Can identify which foods are being consumed by which proportions of the population Can identify which proportion of these foods are purchased Can be disaggregated by region, urban and rural, and income level Can model potential coverage and estimate likely benefit based on apparent consumption levels.

23 HIES: Strengths HIES can determine intakes at the household level from combinations of foods Data are already available, and updated at regular intervals. Longer recall period makes it more suitable for assessing usual intake

24 HIES: Weaknesses HIES yield only household level data HIES can only measure apparent consumption - does not account for food stored, food wasted, or foods consumed outside the home Does not always identify food items specifically enough to accurately calculate their nutrient content

25 Food Balance Sheets and Industry Data

26 Food Balance Sheets and Industry Data: Overview FBS present a comprehensive picture of a country s food supply and utilization over a specified reference period FBS Food available for human consumption = food supply in country utilization sources Both FBS and industry data are used as a planning tool in food fortification programs used in feasibility assessment and design: vehicle selection, fortificant levels

27 FBS and Industry Data: Overview Industry data is a component of both FBS and FRAT (e.g., market survey) Types of industry food production data Volume (food produced, number of producers, etc.) Production and operating capacity Extraction rate Imports/Exports Revenue data Sources FAO, Governments (Ministry of Agriculture, Bureau of Statistics), Industry associations, Individual producers

28 FBS and Industry Data: Strengths FBS: Official government data FBS are publicly available, secondary data and therefore quite cost-effective to use Both can suggest types and quantity of foods available to identify fortification vehicles Enable the observation of general shifts in consumption patterns over time

29 FBS and Industry Data: Weaknesses Food categories may be too vague to identify potentially fortifiable products (e.g. bouillon cubes) Lag in FBS data updates No info on proportion of consumption that is purchased vs. gifted or home produced No info on distribution of available food (geographic, demographic, socio-economic, seasonal)

30 FBS and Industry Data: Weaknesses Data accuracy issues High tax rates and underreporting of production/revenue values Informal sector activity excluded FBS are derived statistics and therefore dependent upon reliability of underlying basic statistics of population, supply and utilization of foods and their nutritive value Data availability issues Commercial interest in collecting these data can be low Often requires personal relationships and a level of trust to obtain these data

31 Suitability of FC Methods for Meeting Information Needs Program Cycle Information Need PROGRAM DESIGN 24HR FFQ FRAT HIES FBS and Which food(s) should be fortified? industry data Foods consumed usually by large proportions of the population? L H H H H Proportion of consumption that is purchased? L L L H L Proportion of the population purchasing who are deficient or at-risk? H H M M L Trends in these consumption or purchase data? M M M H H

32 Suitability of FC Methods for Meeting Information Needs Program Cycle Information Need PROGRAM DESIGN 24HR FFQ FRAT HIES FBS and industry data What levels of micronutrients should be added to food fortification vehicles? What is the nutrient intake gap? H H M L L How is the intake gap distributed in the population? M M M M L How is the consumption of the food vehicle distributed in the population? M M M H L

33 Suitability of FC Methods for Meeting Information Needs Program Cycle Information Need 24HR FFQ FRAT HIES FBS and industry data MONITORING Reach H H H H M Coverage H H H H L Effective coverage H H M L L Excessive coverage H H M L L EVALUATION Improvements in micronutrient intake? What proportion is attributed to the micronutrient intervention? H H M M L H H M M L

34 Relative Resource Requirements of FC Methods Steps involved in using FC method 24HR FFQ FRAT HIES FBS and industry data Instrument development H H M N/A N/A Training H M M N/A N/A Data collection H M M N/A N/A Data entry H M M N/A N/A Data analysis H H M M L

35 Conclusions All FC methods have strengths and weaknesses that vary according to the specific programmatic information requirement. They should be used complementarily to answer different but related questions and to triangulate results.

36 Conclusions, Cont d Method selection should be based on: suitability and validity for purpose data availability resource availability degree of precision required Many methods can be further strengthened for MN programming by simple modifications.

37 Conclusions HIES offers potential for designing fortification programs, and for projecting coverage and potential benefit. Twenty-four hour recall (preferred) or FFQ should be conducted as part of the baseline assessment, to confirm individual level estimates assumed by HIES FFQ would be a suitable, relatively low-cost option for monitoring reach, coverage, and effective coverage.

38 Acknowledgments Name Maria Andersson Grant Aaron Isabelle Aeberli Jack Bagriansky Peter Berti Omar Dary Reina Engle-Stone Jack Fiedler Celia Greenberg Quentin Johnson Janneke Jorgensen Juan Pablo Pena-Rosas Keith Lividini Barbara MacDonald Yves Martin-Prevel Lynnette Neufeld Fabian Rohner Shelly Sundberg Affiliated Organization Swiss Federal Institute of Technology University of California Davis St. John s Research Institute Fortification Consultant Healthbridge AED University of California Davis HarvestPlus Medical Research Council (UK) Quican Inc. World Bank World Health Organization IFPRI GAIN IRD Micronutrient Initiative GAIN Bill and Melinda Gates Foundation