JAMAevidence Glossary

Terms are derived from Users' Guides to the Medical Literature: A Manual for Evidence-Based Practice, 2nd Edition and The Rational Clinical Examination: Evidence-Based Clinical Diagnosis. Updated December 2009.
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Generalizability
The degree to which the results of a study can be generalized to settings or samples other than the ones studied.

Generic health-related quality of life
Generic health-related quality of life (HRQL) measures contain items covering all relevant areas of HRQL. They are designed for administration to people with any kind of underlying health problem (or no problem at all). Generic HRQL measures allow comparisons across diseases or conditions. See also Health-related quality of life.

Genetic heterogeneity
A situation in which a particular phenotype may result from more than one genetic variant.

Genetic marker
A specific genetic variant known to be associated with a recognizable trait.

Genome
The entire collection of genetic information (or genes) that an organism possesses.

Genome-wide association (GWA) study
A study that evaluates association of genetic variation with outcomes or traits of interest by using 100 000 to 1 000 000 or more markers across the genome.

Genotype
The genetic constitution of an individual, either overall or at a specific gene.

Gold standard
A method having established or widely accepted accuracy for determining a diagnosis that provides a standard to which a new screening or diagnostic test can be compared. The method need not be a single or simple procedure but could include follow-up of patients to observe the evolution of their conditions or the consensus of an expert panel of clinicians.

Goodell sign
Softening of the cervix on bimanual examination. May be detected by 8 weeks' gestational age. The progressive edema that develops during pregnancy softens the consistency of the cervix tip to approximate that of the lips (Goodell sign).

Guarding, involuntary
A reflexive spasm of the abdominal musculature in the setting of peritoneal irritation, such as with appendicitis, which cannot be overcome by distraction (also referred to as rigidity).

Guarding, voluntary
Contraction of the abdominal musculature, often due to fear of pain rather than actual pain, but which can usually be partially or fully overcome by using relaxation and distraction techniques.