Nutrition survey

Nutrition Survey - Longitudinal and Cross sectional survey

1. Nutrition Survey P. Karthika Assistant Professor Department of Food Science and Nutrition Periyar University, Salem - 636011

2. Nutrition Survey Types Longitudinal Studies Long period of survey ( upto one year) All type of disease (malnutrition/ beri beri / measles., etc) Cross sectional studies Short period (few days/ week) Specific disease in short time report (case study)

3. Advantages of Longitudinal Studies Study carried out for upto one year the true incidence of malnutrition and disease to be determined Seasonal variations – climate, availability of food, community activities etc. Severe diseases – infantile beri-beri and measles/ impetigo Child born or death – accuracy (date/ death) Growth can be compared with standard (vital Statistics/ age specific period) Attract the doctors to work in rural areas (medical/ paramedical personnel)

4. Disadvantages of Longitudinal Studies Not easy to organize, expensive, time consumption Out of date (community/ people) Constant standards/ methods of examination/ interview – maintained Can not alter with experience Clinical ethical clearance Monitor – carefully for the whole period Seasonal or other movement of people Trained staff may be difficult to recruit Need more patience, dedication and team spirit

5. Techniques Sampling Selection of area Selection of places of examination Regular clinic Home visiting Emergency morbidity clinic survey Selection and training of staff Type and frequency of investigations Data Collection (ABCD, Parasitological data, tuberculin test, health history, socio economic status)

6. Cross sectional survey

7. Observation or descriptive study There is no control to compare Identify the defined population at a particular point Include past and current incidence (history)

8. Advantages of C-S Studies Short term Fewer resources required (Time, Energy, staff) Less statistical analysis More easily controlled Design less complex Inexpensive

9. Advantages of C-S Studies (Cont.) Provide relationship between attributes of disease and characteristics of various groups, Data is useful for planning of health services and medical programs

10. Disadvantages of C-S Studies Represent only those who are surveyed Identify prevalence, not incidence necessarily excludes cases that died before study was done Does not provide authentic information for acute conditions of short duration

11. Disadvantages of C-S Studies (cont.) Often, not possible to establish temporal relationship between exposure and onset e.g. does high cholesterol precede CHD? Not too effective if disease levels are low Therefore , difficult to establish a causal relationship Data can be only suggestive of causation

12. PRD- 13 Steps in cross sectional studies

13. PRD- 14