Kaplan–Meier and adjusted survival curves comparing insulin monotherapy and insulin plus metformin for all-cause mortality (a and b), MACE (c and d), and cancer (e and f).

<p>Blue = insulin monotherapy, green = insulin plus metformin. Time zero refers to index date plus 180 days. For the adjusted survival curves, a non-time-dependent Cox model was used, where insulin dose was modelled as the mean value for the follow-up period. The proportional hazards assumption was violated for history of cancer (all-cause mortality), history of receiving antihypertensive therapy (all-cause mortality), and serum creatinine (cancer).