Fig. 4: Risk differences in dementia onset over time are negligible for metformin initiators, as compared to sulfonylureas.

Cumulative incidence functions (CIF) or risk curves, along with their 95% CIs (represented by shaded areas), based on pointwise 0.025- and 0.975-quantiles of sample bootstrap distributions, were estimated using the Cox model for the cause-specific hazards, with only treatment as a covariate and baseline covariate distributions between treatment arms balanced by IPTW. a, b CIF curves for dementia onset (in blue hues) and competing death (in orange hues) for metformin vs. sulfonylurea initiators. Follow-up times are up to 12 and 16 years in the US RPDR (a) and the UK CPRD (b) cohorts, respectively. c, d Risk difference curves for dementia onset (in blue) and competing death (in orange), in the US RPDR (c) and the UK CPRD (d) cohorts, respectively. A negative risk difference value during certain time periods indicates that initiation of metformin is beneficial, as compared to sulfonylureas.