Dealing with redundant gamma glutamyl transpeptidase in primary care, when requested along with alkaline phosphatase

The use of gamma glutamyl transpeptidase (GGT) levels as screening test for liver function is controversial. The GGT main utility is in cases in which alkaline phosphatase (ALP) is elevated. We aimed to investigate the request over time for alanine amino transferase (ALT), ALP and GGT, study the effect of a new demand management (DM) intervention for optimal GGT measurement in primary care. Our descriptive study was conducted from January 2010 to December 2020. The intervention was established in November 2019 and consisted of the laboratory information system would automatically remove GGT, if the test had been ordered simultaneously with ALP and there was no prior pathological result on record. We counted the absolute number of measured ALT, ALP and GGT, and calculated the ratios for each of the three markers related to creatinine, and GGT related to ALT in a monthly basis. The number of measured GGT increased slightly and progressively along the study until October 2019, when a decrease was observed. The ALT and ALP request from primary care also increased slightly along years. However, the GGT/ALT ratio never reached the 0.2 goal. Out of the 57,614 GGT requested in primary care patients, 38,167 (66.2%) were not measured. 7633.4€ were saved in reagent. The DM intervention to reduce the measurement of GGT when requested redundantly with ALP in primary care was successful, and the results have been maintained over time as observed by monitoring the GGT/CREA and GGT/ALT indicator results.