In clinical trials with multiple visits, dropouts often occur and the population of patients who dropped out may be different from the population of patients who completed the study. To assess treatment effects over the population of all randomized patients, which is called the intention-to-treat analysis and is required by regulatory agencies, last observation analysis (LOAN) focuses on the la...

Analysis of covariance (ANCOVA) is a powerful statistical tool for adjusting an analysis to acoount for the effects of concomitant variables. The technique may be applied to completely randomized designs (CRO) as well as repeated measures designs. In addition to normality assumptions, ANCOVA depends on assumptions about variances and slopes. Although not usually provided directly, most statisti...