Illustration of typical imputed values for a subject in the treatment group that drops out of the trial after Week 1 for four different assumptions concerning the missingness mechanism. The black squares (■) are the observed means in the placebo group and the open squares (□) are the observed means in the treatment group. The asterisks represent either observed (Weeks 0 and 1) or imputed (Weeks 3, 5, and 8) values for the subject who dropped out of the trial.

Cai X, Gewandter JS, He H, Turk DC, Dworkin RH, McDermott MP. Estimands and missing data in clinical trials of chronic pain treatments: advances in design and analysis. Pain. 2020;161(10):2308-2320. doi:10.1097/j.pain.0000000000001937