Table 1. Study keywords for this meta-analysis.

Using EMBASE

Terms related to thesaurus

#1   [related to genetic backgrounds]

“genetic variability” OR “genetic polymorphism” OR “single nucleotide polymorphism [Exp]” OR “genetic association” OR “genotyping” OR “genetic susceptibility” OR “genetic resistance” OR “genetic predisposition”

#2   [related to type 2 diabetes mellitus]

“non insulin dependent diabetes mellitus -- epidemiology” OR “diabetes mellitus -- epidemiology”

#3   #1 AND #2

Using MEDLINE

#4   [related to genetic backgrounds]

“Genome-Wide Association Study” OR “Genetic Association Studies” OR “Polymorphism, Single Nucleotide” OR “Genetic Variation [Exp]” OR “Polymorphism, Genetic [Exp]” OR “Genotype” OR “Genetic Predisposition to Disease”

#5   [related to type 2 diabetes mellitus]

“Diabetes Mellitus, Type 2 -- epidemiology” OR “Diabetes Mellitus, Type 2 -- genetics” OR “Diabetes Mellitus -- genetics” OR “Diabetes Mellitus -- epidemiology”

#6   #4 AND #5

Combination of EMBASE and MEDLINE

#7   #3 OR #6

[Exp] indicates automatic inclusion of all the narrower terms under the specified descriptor in the thesaurus hierarchy.

Using the connector “--” limits a descriptor term to a Subheading appearing after the connector.