Fig. 6.

This figure shows the observed response rate (dashed line, open square) and the PAVA (pooled adjacent-violators algorithm: one of the isotonic regression estimation method that constrains the point estimates to either increase or decrease monotonically)-adjusted response rate (solid line, solid triangle) at each remifentanil concentration. The observed response rate and PAVA-adjusted response are equal at certain concentrations. The PAVA-adjusted response rate is monotonically increased.