Sensitivity of strategy optimality to discount rate and timeframe. The probability that each strategy is optimal across a range of cost-effectiveness thresholds was evaluated for combinations of annual discount rates of (A, D, and G) 1%, (B, E, and H) 3%, and (C, F, and I) 5% and timeframes of (A–C) 5 y, (D–F) 10 y, and (G–I) 20 y. Rabies programs evaluated include maintenance of the status quo (gray lines), expanding targets for exclusive canine vaccination (CV; blue lines of progressively deeper shades), and expanding targets of combined canine vaccination and female sterilization (CVFS; red lines of progressively deeper shades). Canine vaccination with sterilization of both males and females is never optimal and is not shown here. The vertical dotted and dashed lines indicate the WHO thresholds for very cost-effective and cost-effective strategies in India ($1,582 and $4,746 per DALY), respectively.