RT Journal Article SR Electronic T1 Redundant laboratory testing on referral from general practice to the outpatient clinic JF BJGP Open JO BJGP Open FD Royal College of General Practitioners SP BJGPO.2021.0134 DO 10.3399/BJGPO.2021.0134 A1 Bram EL Vrijsen A1 Maarten J ten Berg A1 Wouter W van Solinge A1 Jan Westerink YR 2021 UL http://bjgpopen.org/content/early/2021/10/01/BJGPO.2021.0134.abstract AB Background Inappropriately repeated laboratory testing is a commonly occurring problem. However, this has not been studied extensively in the outpatient clinic after referral by general practitioners.Aim The aim of this study was to investigate how often laboratory tests ordered by the general practitioner were repeated on referral to the outpatient clinic, and how many of the normal test results remained normal on repetition.Design & setting This is a post hoc analysis of a study on laboratory testing strategies in patients newly referred to the outpatient clinic.Method All patients who had a referral letter including laboratory test results ordered by the general practitioner were included. These results were compared to the laboratory test results ordered in the outpatient clinic.Results Data were available for 295 patients, 191 of which had post-visit testing done. In this group, 56% of tests ordered by the general practitioner were repeated. Tests with abnormal results were repeated more frequently than tests with normal results (65% vs 53%; P<0.001). A longer test interval was associated with slightly smaller odds of tests being repeated (OR 0.97 [0.95–0.99]; P=0.003). Of the tests with normal test results that were repeated, 90% remained normal. This was independent of testing interval or testing strategy.Conclusion Laboratory tests ordered by the general practitioner are commonly repeated on referral to the outpatient clinic. The number of test results remaining normal on repetition suggests a high level of redundancy in laboratory test repetition.