Figure 2: Additional T_L (in years) of each of drugs A (ceftriaxone-like) and B (new antibiotic) by strategy relative to that of the reserve strategy (T_L strategy–T_L reserve), based on properties of a new antibiotic B.

Strategies (x-axis) were compared over a range of plausible parameter values for ω_B (y-axis) and f_B (vertical facets). These properties were held constant for drug A: ω_A=0·98 and f_A=10⁻⁸. The model run time was extended to 100 years because some parameter sets increased the lifespan of available antibiotics to more than 40 years for all strategies. If the lifespan of the drugs extended beyond 100 years, that strategy’s results are shown either in relative terms for comparison or with an unlabelled dark purple tile, if no strategies on the x-axis had a defined T_L under that parameter set for drug B. f_B=fitness of drug B resistant strains relative to susceptible bacteria. T_L=time in years until both drugs A and B hit their 5% resistance thresholds, warranting new treatment recommendations. ω_B=probability of emergence of resistance upon treatment with drug B.