Intervention to reduce vitamin testing in primary care: a randomized controlled trial

Abstract

BackgroundAlthough vitamin tests are increasingly ordered by GPs, an evidence-based indication is often lacking.AimTo rationalise and reduce ordering of vitamin D and B12 tests by educating GPs and their patients about the merits and pitfalls of performing vitamin tests.MethodA two-armed cluster randomised study assessing the effectiveness of two separate interventions on the number of vitamin tests ordered. In total 26 health centres in the Netherlands participated (200 000 patients). De-implementation group 1 received education and a 3-monthly benchmarking of their own vitamin test ordering behaviour. De-implementation group 2 received the same intervention, but supplemented with educational material for patients. The primary study endpoint was the total reduction in vitamin D and B12 tests ordered at the end of the study as compared to a 1-year pre-intervention period. Secondary outcomes were the number of deficient test results, the number of (high dose) vitamin prescriptions, and the direct cost savings.ResultsThe number of vitamin D tests ordered at the end of the 1-year study period as compared to a 1-year pre-intervention period decreased with 23%. For vitamin B12 tests an overall reduction of 20% was found. Adding patient information had additional value over training and benchmarking of GPs, which was significant for vitamin D (−29% with and −19% without patient information), compared to respectively −22% and −18% for vitamin B12.ConclusionA structured intervention programme, including training of GPs and benchmarking their ordering of diagnostic tests, resulted in a significant reduction in ordered vitamin tests.