Observed pattern in group B at the times (T1, T4, T6) | Imputed value in group B at T1 | Imputed value in group B at T4 | Imputed value in group B at T6 |
---|---|---|---|
mis*, mis, mis | X1-bar† | X4-bar‡ | X6-bar§ |
mis, mis, Y3¶ | Y3—(delta1**+delta2††)‡‡ | Y3—delta2 | |
mis, Y2, mis | Y2—delta1 | Y2+delta2 | |
Y1, mis, mis | Y1+delta1 | Y1+delta1+delta2 | |
Y1, Y2, mis | Y2+delta2 | ||
Y1, mis, Y3 | (Y1+delta1+Y3—delta2)/2 | ||
mis, Y2, Y3 | Y2—delta1 |
The use of imputed quantities derived from observed values in a group (group A) to impute missing values in a group (group B).
*The value at T4 is missing in group B.
†Mean of values observed in group A at time T1.
‡Mean of values observed in group A at time T4.
§Mean of values observed in group A at time T6.
¶Observed value in group B at time T6.
**The mean of difference between value observed at time T4 and observed at time T1 in group A.
††The mean of difference between value observed at time T6 and observed at time T1 in group A.
‡‡If an inputed value is <0 it is set equal to 0.