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Unformatted text preview: Community Nutrition
GCH 421 Chapter 3 Plan for collecting data Decisions about which data to collect are thought Decisions about in great depth. about The plan helps to determine which questions to The ask and which data to collect. ask Most important planning activities should be Most completed before data collection begins: completed Review the purpose, goals, and objectives of Review the needs assessment the Develop a set of questions related to the target Develop population’s nutritional problem, how it developed, and/or the factors that influence it. developed, Choose a method for obtaining answers to these Choose questions. questions. Types of data to collect about target population Individual lifestyle factors Lifestyle – Physical activity, choice of leisure Lifestyle activities, ability to handle stress, etc. activities, Can ask broad or specific questions. Diet – Key individual factor to be analyzed. Can look at questions related to Food supply, Can Food intake, and nutrient utilization. Food Living, Working, and Social Conditions Education, occupation, and income all have Education, great effects on health and nutrition. great Methods of Obtaining Data about the Target Population
Survey Health Risk Appraisal Screening Focus Groups Interviews with Key Informants Direct Assessment of Nutritional Status Survey Survey is a systematic study of a cross-section of Survey individuals who represent the target population. individuals They can be used to collect qualitative or They quantitative data in formal structured interviews. (Some are self-administered and others are done by interviewers.) by Nutrition survey – An instrument designed to Nutrition collect data on the nutrition status and dietary intake of a population group. intake These must have a well-defined purpose (Ex: These Determine the nutritional status of a population.) population.) Look at Table 3-2 (page 75) to see questions to Look ask when designing a survey. ask Health Risk Appraisal (HRA) is a type of survey instrument used to (HRA) characterize a population’s general health status. characterize It is a kind of “health hazard chart” that asks It questions about the lifestyle factors that influence disease risk. disease It has a questionnaire, certain calculations, and an It educational health message or report to the participant. participant. Let’s look at Figure 3-2 p. 76 to see an example. Screening
This is designed to reverse, retard, or halt This the progress of a disease by detecting it as soon as possible. soon Some common screening procedures are Some found on page 77, table 3-3. found Focus Groups
An informal group of about 5 to 12 people An who are asked to shared their concerns, experiences, beliefs, opinions, or problems. experiences, Usually lasts about 1 to 3 hours. Led by a trained moderator who is skilled at Led promoting group interaction. promoting Explore topics and make no judgments. Difficult to analyze this data. Interviews with Key Informants
Key informants are the people “in the Key know” about the community. know” They may have worked with the target They population or conducted research related to health and nutrition. health Direct Assessment of Nutritional Status Dietary Assessment Methods Used to determine and individual’s or population’s Used usual dietary intake and to identify potential dietary inadequacies. inadequacies. administer, time consuming, requires trained interviewer, not practical for large populations. interviewer, Diet History – detailed questionnaire, easy to in-person or phone, useful for large populations because it requires little time, does not provide accurate estimate of individual’s usual dietary intake. intake. 24 hour recall – widely used, administered by or 7 days, provides detailed information about food intake including brands, method of preparation, need highly motivated, literate well-trained respondent. respondent. Diet Record “gold standard” completed over 3,4 semi-quantitative food frequency questionnaire that categorizes individual’s intake of selective nutrients (vit A, vit C) self administered, relatively cheap, easy and quick, accuracy of reporting depends on memory, food lists must include foods commonly consumed by population being surveyed consumed Food Frequency Method – large scale use, Laboratory Methods Can measure taste acuity, and nutrient status, but are Can often too expensive in the field. often Anthropometric Methods Measurements of the body’s physical dimensions and Measurements composition are used to detect moderate and severe degrees of malnutrition and chronic imbalances in energy and protein status. These are common in largeenergy scale assessments. Clinical Methods – Medical history and a physical examination. examination. Issues in Data Collection Practical Issues Cost, feasibility, amount of time. The assessment method should be simple to The administer, take only a few minutes, be inexpensive, and be safe. inexpensive, Scientific Issues Sensitivity vs Specificity tests (which one?) Sensitivity – Proportion of individuals in the sample with the disease or condition who with have a positive test for it. (ex: phlebotomy) have Specificity – The proportion of individuals in the sample without the disease or without condition who have a negative test. (ex: oral glucose tolerance) glucose Validity and Reliability Validity – The accuracy of the assessment accuracy instrument. instrument. Can be affected by many factors: • Characteristics of the respondent Characteristics (literacy, education, etc.) (literacy, • Questionnaire design – Difficulties of Questionnaire instructions/ instructions/ • Adequacy of reference data • Accuracy of data input and management Reliability – The repeatability or precision of Reliability the instrument. the Cultural Issues Together with a partner select an issue concerning Together nutritional status of a chosen population or target group nutritional Identify the population you want to survey – explain why Identify you have chosen this population for this particular nutritional issue nutritional List five questions you might ask to understand their food List habits habits Describe three other methods by which you can gather Describe information on their nutritional status (what tool will you use?) use?) What would affect the validity (accuracy) of your What instrument? instrument? What would affect the reliability (reproducibility) of your What instrument? instrument? ...
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This note was uploaded on 01/12/2011 for the course GCH 421 taught by Professor Berkow,s during the Spring '08 term at George Mason.
- Spring '08