Aims:  Our goal was to determine the effect of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) consensus algorithm for the initiation and adjustment of type 2 diabetes (T2D) therapy, published in 2006, on the incidence of early metformin monotherapy (EMM), defined as the prescription of metformin and no other antidiabetic medications within 30 days of initial T2D diagnosis.

Methods:  The incidence of EMM in the United States (US) from January 2005 to December 2007 was estimated using data from the i3 InVision™ Data Mart, an integrated database of enrolment dates, inpatient and outpatient medical claims, pharmaceutical claims, and laboratory results from a diverse group of US health plans. The trend in the incidence of EMM was analysed using joinpoint regression modelling.

Results:  A statistically significant joinpoint was found in July 2006 (p < 0.05). From January 2005 to July 2006, EMM increased at an annualised rate of 15.6%. From July 2006 to December 2007, EMM increased at an annualised rate of 66.0%.

Conclusions:  Our findings suggest that publication of the ADA/EASD algorithm caused a significant acceleration in the incidence of EMM.