Fig. 3. Ratio of the metabolite GR90291 concentration and remifentanil concentration after 150 min according to gestational age. Box plots represent median, IQR, minimum, and maximum. Values more than 3 IQR from the box are labeled as extreme and denoted by an asterisk (*). Values more than 1.5 IQR but less than 3 IQR from the end of the box are labeled as outliers (o). IQR = interquartile range.