Influence of specific clinical lessons in the Dutch Journal of Medicine on clinical management

OBJECTIVE: To establish whether publication of an article propagating a laboratory test leads to measurable increase of the number of requests for that test. DESIGN: Retrospective. METHOD: From volume 138 (1994) of the Dutch Journal of Medicine (NTvG), three clinical lessons were selected that contained an unequivocal clinical message and a recommendation to request a specific laboratory test for particular patients. All laboratories performing the test in question were asked to report the number of requests per month in the months before, after and during publication of the article in question and during the same months of 1993. The difference between the number of requests in the period after publication of the article in 1994 and in the same period in 1993 was determined and tested postulating a Poisson distribution. RESULTS: Regarding two clinical lessons (one about determination of Coxsackie virus in neonates and one about examining arthritis patients for parvovirus B19) no significant difference in the numbers of requests before and after the publication was found, particularly also because the laboratories could not supply itemized data so that relevant information was lost in a flood of other data. The third clinical lesson (about determination of antibodies against Onchocerca in patients complaining of itching after a trip to the tropics) was followed by a significant increase of the number of requests (from 50 to 90; p < 0.001) in the 3 months following publication. CONCLUSION: Publication of a clinical lesson about a recommended laboratory test for onchocerciasis in the NTvG resulted in a significant rise of the number of requests for that test.