Figure 1.

The schematic depiction of the four baseline adjustment methods.

Notes: Post score refers to posttreatment score, the outcome of the study. B_o refers to the baseline covariate used to adjust the score. Δ is the change score, calculated by subtracting the baseline score from the posttreatment score. The four methods depicted in Figure 1 are referred to, in this paper, as posttreatment, change, percent change, and analysis of covariance (ANCOVA).