Fig. 2

MAE in the non-monotonic case (the proportion of the unit non-response and the item non-response includes 0.2:0.8, 0.5:0.5, 0.8:0.2). Abbreviations: MAE mean absolute error, MCAR missing completely at random, MAR missing at random, MNAR missing not at random, MMRM mixed model for repeated measures predictive imputation at the item level, MICE multiple imputation by chained equations at the item level, MMRMD mixed model for repeated measures directly at the composite score level, SCORE-MICE multiple imputation by chained equations at the composite score level, J2R jump to reference at the item level, CR copy reference at the item level, CIR copy increments in reference at the item level, LOCF last observation carried forward