Diagnostic yield of blood tests for unexplained complaints [De diagnostische opbrengst van bloedonderzoek bij onbegrepen klachten]

General practitioners fail to establish a specific diagnosis on the basis of history and physical examination in 3-39% of patients at their first visit. While it is generally assumed that these unexplained symptoms are not serious and are transitory in nature, they are sometimes the first signs of a disorder. The VAMPIRE-study (VAgue Medical Problems In REsearch) showed that while the diagnostic yield of blood tests ordered directly or after a delay is the same, in absolute terms direct blood tests are more expensive and are accompanied by more false-positive results than delayed tests. Moreover, the relative number of false-positive results increases substantially with increasing number of blood tests ordered. These results support the recommendations of the now withdrawn guideline on blood tests of the Dutch College of General Practitioners, which advised limiting the number of tests performed and waiting 4 weeks before these tests are ordered.