Past exam of the mathematics course of the University of Cambridge / 2019 / iii / Paper 207 / 3 / 1 / Solution

Let $Y_{it}$ be patient $i$'s QoL at visit $t$ and let $R_i$ be the last visit at which QoL is observed. The data are monotone missing-data pattern whenThus each patient contributes an observed prefix $(Y_{i0},\dots ,Y_{i{R}_i})$ followed by a missing suffix.