Observational studies part 2

Glycemic Index (GI)

A ranking of the effect, on blood glucose, of a food of a certain carbohydrate content relative to an equal amount of carbohydrate from a reference food, usually 50g of glucose or white bread containing 50 g of digestible (available) carbohydrate.

A Priori Subgroup Analysis

Used to detect sources of heterogeneity.

Subgroup Analysis

A process to determine whether a factor (e.g., study quality) is a source of heterogeneity, involving dividing studies into strata (e.g., high quality vs. low quality scores) and conducting meta-analysis for each stratum. If the subgroups differ significantly, the factor may be a source of heterogeneity; if they do not differ significantly, it is not

Heterogeneity

Refers to real differences between studies