EtG/EtS can detect ethanol metabolites for days, carbohydrate-deficient transferrin (CDT) and phosphatidyl ethanol (PEth) can detect for weeks, while glutamyltranspeptidase (GGT) and mean corpuscular volume (MCV) have a detection window from weeks to months. (
paraphrasing Wurst, F 2003) Fred Wurst, Univ of Ulm (Germany) is credited with operationalizing EtG as a bio-marker for alcohol consumption.
The other tests are far less specific than EtG/EtS, seldom used outside forensic toxicology. The study above compares them on a small hospital population.
They are also blood tests and limited in scope. PEth for instance is valid only after ingestion of alcohol daily across a period. CDT/GGT are usually used together to reach diagnostic significance. These tests actually predate EtG/EtS. MCV is of little use independent value.