Merck has reported data from an observational study that assessed the differences in initiated insulin therapy in patients with type 2 diabetes taking a combination of Januvia (sitagliptin) and metformin, as well as sulphonylurea and metformin.
The study found that patients administered with a combination of sitagliptin and metformin initiated insulin therapy at a slower rate than patients treated with sulphonylurea and metformin.
The study used a propensity score matched sample from the GE Centricity Electronic Medical Record database.
Under the study, initially 7,728 patients with type 2 diabetes were administered with sitagliptin or sulphonylurea as dual therapy with metformin for at least 90 days after starting sitagliptin or sulphonylurea in 2006 to 2013.
The company used the Kaplan-Meier estimator to find out the progression to insulin use between the groups using sitagliptin and metformin, and sulphonylurea and metformin.
To find out the progression to insulin use by year, the physicians used the Cox proportional hazards regression model.
However, the study had number of limitations including unavailability of data for day-of-supply for prescription and stopping dates of medications, no clear information regarding whether patient took medications as per the physician's prescription, amongst others.
Merck said in a statement: "Due to the methods employed in this analysis, the time period in which an outcome can be observed must be prespecified and patients without complete data needed to be excluded."