Paired design [General Statistics]
Hi ElMaestro & Silva,
This is not a crossover but a paired design.
Right.
The only application of a paired design I’m aware of is to assess whether PK is linear by comparing AUC0–τ (steady state = T) with AUC0–∞ (single dose = R). Nobody would perform such a study as a crossover since the logistics would be terrible. ElMaestro correctly stated
Hence, it should be unambiguously stated in the protocol that the model assumes (!) no period effect, i.e., the difference is related solely to the treatment. Contrary to a crossover where period effects mean out (unless sequences are extremely unbalanced) in a paired design great care must be taken to avoid a true period effect – which would confound the treatment effect.
Stupid example: No air conditioning in the clinics and a heat wave during SD.
@Silva: Is this was you are planning?
❝ ❝ In a crossover study using only one sequence (RT for ex.) […]
This is not a crossover but a paired design.
❝ There is no sequence effect here because Sequence only has one level.
❝ Period and Treatment will have the same meaning;
Right.
❝ But are you sure this is a design you really want to use???
The only application of a paired design I’m aware of is to assess whether PK is linear by comparing AUC0–τ (steady state = T) with AUC0–∞ (single dose = R). Nobody would perform such a study as a crossover since the logistics would be terrible. ElMaestro correctly stated
❝ Period and Treatment will have the same meaning;
Hence, it should be unambiguously stated in the protocol that the model assumes (!) no period effect, i.e., the difference is related solely to the treatment. Contrary to a crossover where period effects mean out (unless sequences are extremely unbalanced) in a paired design great care must be taken to avoid a true period effect – which would confound the treatment effect.
Stupid example: No air conditioning in the clinics and a heat wave during SD.

@Silva: Is this was you are planning?
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Complete thread:
- Using only one sequence Silva 2016-07-28 09:13 [General Statistics]
- Using only one sequence ElMaestro 2016-07-28 09:51
- Paired designHelmut 2016-07-28 11:09
- Paired design Silva 2016-07-28 12:17
- Dose escalation Helmut 2016-07-28 12:47
- Paired design Silva 2016-07-28 12:17
- Paired designHelmut 2016-07-28 11:09
- Using only one sequence DavidManteigas 2016-08-01 11:17
- Using only one sequence ElMaestro 2016-07-28 09:51