Fig. 2

Standardized residuals of the proportion-resistant equilibrium level linear regression models for the three behavior modes. The three behaviors of the resistant bacteria in the example mathematical model were: (a, b) increasing, (c, d) decreasing, and (e, f) increasing during antimicrobial therapy and decreasing after therapy ceases (peaked). Separate linear regression models were built for each of the absolute (a, c, e) and relative (b, d, f) equilibrium levels in each behavior mode and are described in Table 1. The relative equilibrium level (b, d, f) is the proportion of resistance at the equilibrium point minus the starting proportion of resistance. The fitted values of the equilibrium level outcome are shown on the x-axis and the standardized residual values are shown on y-axis