Figure 1From: Investigation of continuous effect modifiers in a meta-analysis on higher versus lower PEEP in patients requiring mechanical ventilation - protocol of the ICEM study The variety of curve shapes available with the FP1 family of transformations of a continuous predictor, x. FP1 transformations are simply powers of the form x p. For example, x p with power Pā=āā1 is the reciprocal (1/x) of x. These powers are indicated by the numbers on the diagram. Adapted from Royston and Sauerbrei [10].Back to article page