GLP1R and diabetes mellitus: We did not consider glucagon-like peptide-1 receptor agonists because this class was rarely prescribed as a second line antidiabetic treatment in the UK during the study period,12, 13 and they are still not recommended as second line treatment for people with type 2 diabetes mellitus.12 The prescribing of glucagon-like peptide-1 receptor agonists is increasing in the US, however, and warrants further study as the number of people prescribed these drugs increases in routinely collected data.