|
Finally,
suppose that we have an extreme case of carry-over and that the
effect of the verum is permanent and irreversible. The only change
that needs to be made to the above table is in the cell corresponding
to the second period of the second sequence. There the response
will be four higher than it would have been without the carry-over
and so the table now looks like this.
| Table
2.4: AB/BA Cross-over trial comparing a verum and a
placebo
|
|---|
| Sequence
| Period
1
| Period
2
| Difference
|
|---|
| PV | 6 | 7 | 1 |
| VP | 15 | 12 | 3 |
|
Mean | | | 2 |
|
Question
2.3
Does
the carry-over effect affect our estimate of the treatment effect?
|