Figure 1.

Relationship between serum creatinine and type 2 diabetes. Left: Estimated functional relationship between serum creatinine and T2DM using Generalized Additive Models (GAM). Breakpoints and 95% CIs from a piecewise linear models at the bottom. Right: Corresponding odds ratios (approximately 0.90 below and 1.0 above the breakpoints). Given the large uncertainty in the location of the breakpoints the graph does not take the shape of the idealized step function a piecewise linear model assumes, but has a marked transition face.