Key Concepts in Nutrition Assessment and Research Methods

Target population

The population in which the results of the study will be applied

Representative sample

In every study, the sample should be a representative of the population; otherwise, all statistical calculations are not valid

P value

In hypothesis testing, it gives the probability that the result in the sample is merely caused by chance; it does not give the magnitude and direction of the difference

Confidence interval

Indicates an estimate of the value in the population given one result in the sample; it gives the magnitude and direction of the difference

Assent

Type of informed consent when the research participants are 0-17 years old or minor

Kappa test

Test used for measuring the agreement between 2 categorical measures

Reproducibility

Refers to the degree to which repeated measurements of the same variable give the same value

Subcutaneous fat

What skinfold thickness is actually a measure of

Serum retinol

Biochemical sample analysis of Vitamin A nutriture used by the NNS

Deficient

According to the WHO, a plasma retinol of 5 mcg/dL is defined as

Systematic

One of the characteristics of research; it means it follows the rigid process of investigation

Case-control study

Type of studies where matching of research participants is needed

Odds ratio

Measure of the association of exposure and outcome in a case-control study

FFQ

Primary method of dietary assessment used in determining the relationship of diet and disease in nutritional epidemiological studies

BMI

Body Mass Index; calculated as weight (kg) divided by height squared (m^2)

Index

A simple numerical ratio constructed from two or more raw anthropometric measurements or a combination of measurements

Chi-square test

Statistical test used to determine whether stunting is related to living in a rural or urban area

Dual-energy X-ray absorptiometry

Body composition method used to measure body mineral content

Mid-upper arm circumference

Circumference of the upper arm at the midway between the shoulder tip and the elbow tip on the left arm

Replicability

Aspect of research where we apply replicability in methodology

Research question

A statement that identifies the phenomenon to be studied and could be gathered from theory, literature, or experience

Cluster randomized trial

Specific research design best suited to evaluate the effectiveness of vitamin supplements on childhood mortality in 450 villages

Underwater weighing

Most direct method for measuring body composition

Cross sectional study

In this study population, the prevalence of CHD is 2 times higher among those with high cholesterol compared to those with normal or low cholesterol

Midstream research

Research implemented to produce new materials based on gained knowledge for regional higher education institutions

Dietary diversity

Measure of the number of food groups consumed over a reference period, usually 24 hours