Reducing vitamin test ordering in primary care; the effectiveness of professional and patient oriented strategies in a Cluster randomized Intervention Study.

Background Vitamin tests are increasingly ordered by GPs, but a clinical and evidence based indication is often lacking. Harnessing technology, ie, decision support tools and redesigning request forms, have been shown to reduce vitamin D requests. Aim Could the number of vitamin tests also be reduced by providing a multi-level intervention programme based on training, monitoring and feedback? Design & Setting In a Cluster Randomised Intervention Study performed in 26 primary care health-centres (200.000 patients) the relative reduction in ordered vitamin D and B12 tests was determined after introduction of two de-implementation strategies (may 2017-may 2018). Method Health-centres randomised to de-implementation strategy one received education and 3-monthly benchmarking of their own vitamin test ordering behaviour. Health-centres in de-implementation strategy two received the same education and benchmarking but supplemented with educational material for patients. Results The number of vitamin D tests decreased 23% compared to the one-year pre-intervention period. For vitamin B12 tests an overall reduction of 20% was found. Provision of patient educational information showed additional value over training and benchmarking of GPs alone, but only for vitamin D test ordering (10% extra reduction, OR 0.88, 95% CI 0.83–0.92, compared to 4% extra reduction for vitamin B12, OR 0.96, 95% CI 0.91–1.02). Nationwide, this would result in over € 3.200.000 saving on healthcare expenditure per year. Conclusion A structured intervention programme, including training and benchmarking of GPs regarding their diagnostic test ordering resulted in a significant reduction in ordered vitamin tests. Additional information provision to patients resulted in a small but still relevant additional reduction. If implemented on a national level, a substantial cost saving can be achieved.