Evaluation of a provincial intervention to reduce redundant hemoglobin A1c testing

Background: The Canadian Diabetes Association recommends testing most individuals with diabetes mellitus using HbA1c once every 3 months. In Alberta, Canada, a provincial intervention to reduce inappropriate HbA1c test orders was implemented to align with this guideline, where only one HbA1c test request every 90 days for most individuals can be processed. Here, we evaluated the provincial intervention to reduce redundant HbA1c testing in Alberta. Methods: Total counts of all HbA1c tests ordered within Edmonton and Calgary, Alberta, were collected from the respective Laboratory Information Systems each month between January 2013 and December 2016. Winters' Additive time series model was built to predict the HbA1c test volume after intervention (November 1, 2015 onwards) and compared with the observed test volume to estimate the effect of the intervention. The estimated change in test volume was then multiplied by the estimated cost to determine the economic impact. Results: During the first 14 months of the intervention for Alberta, there was a 3.3% reduction in the number of observed HbA1c tests compared to the predicted volume. With an estimated marginal reagent cost of $3.50 per unit, this resulted in a cost savings of $145,422 in the first 14 months of the provincial intervention. Conclusion: A modest reduction in HbA1c test orders was observed in the urban areas of Alberta since the implementation of this provincial initiative.