Effect of a price display intervention on laboratory test ordering behavior of general practitioners

Background Redundant use of diagnostic tests in primary care has shown to be a contributor to rising Dutch healthcare costs. A price display in the test ordering system of the electronic health records (EHRs) could potentially be a low-cost and easy to implement intervention to a decrease in test ordering rate in the primary care setting by creating more cost-awareness among general practitioners (GPs). The aim of this study was to assess the effect of a price display for diagnostic laboratory tests in the EHR on laboratory test ordering behavior of GPs in the Westelijke Mijnstreek region in the Netherlands. Methods A pre-post intervention study among 154 GPs working in 57 general practices was conducted from September 2019, until March 2020, in the Netherlands. The intervention consisted of displaying the costs of 22 laboratory tests at the time of ordering. The primary outcome was the mean test ordering rate per 1.000 patients per month, per general practice. Results Test ordering rates were on average rising prior to the intervention. The total mean monthly test order volume showed a non-statistically significant interruption in this rising trend after the intervention, with the mean monthly test ordering rate levelling out from 322.4 to 322.2 (P = 0.86). A subgroup analysis for solely individually priced tests showed a statistically significant decrease in mean monthly test ordering rate after implementation of the price display for the sum of all tests from 67.2 to 63.3 (P = 0.01), as well as for some of these tests individually (i.e. thrombocytes, ALAT, TSH, folic acid). Leucocytes, ESR, vitamin B12, anti-CCP and NT-proBNP also showed a decrease, albeit not statistically significant (P > 0.05). Conclusions Our study suggests that a price display intervention is a simple tool that can alter physicians order behavior and constrain the expanding use of laboratory tests. Future research might consider alternative study designs and a longer follow-up period. Furthermore, in future studies, the combination with a multitude of interventions, like educational programs and feedback strategies, should be studied, while potentially adverse events caused by reduced testing should also be taken into consideration.