Association between midazolam consumption and length of mechanical ventilation. A positive, nonlinear association between midazolam and length of mechanical ventilation was found (P = 0.022) in a mixed linear model. Each point represent the variable per each intensive care unit per month. x- and y-axes are in natural logarithmic scale. Solid gray line represents the best fit between variables. Blue bands represent the 95% of confidence interval from the fit.