GCG and type 2 diabetes mellitus: In addition, starting in 2015, clinical guidelines began favoring new, more expensive drugs as second-line treatments for type 2 diabetes, including sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide 1 agonists.33 To the extent that the ILI and control groups had varying needs for these new agents, this may also have affected differences in prescription drug costs and total health care spending after our sample period.