Fig. 2
From: A comparison of methods to adjust for continuous covariates in the analysis of randomised trials
Estimated associations for different methods of analysis for y = x2. *To obtain the estimated association between f(x) and y for each method of analysis, we first generated a single data set from the model y = x2 + ε (where ε ~ N(0, 1). We then fit a linear regression model of the form y = f(x) to obtain the estimated association