Bioequivalence and Bioavailability Forum • Partial vs. sequential tests in WNL

Partial vs. sequential tests in WNL [Software]

posted by Helmut – Vienna, Austria, 2014-07-01 14:26 (3957 d 17:06 ago) – Posting: # 13187
Views: 27,420

Hi Zan,

❝ The document #98-392 is hidden in page 52 of the PDF file […].

It took the FDA until Sep 1999 to answer a letter received in Oct 1998. Note that this was well before the 2001 Stat. Guidance. Amazingly the letter deals with a one-week (!) washout and the same interval between groups.

┌───────────────┬──────────┬──────────┬──────────┬──────────┐

│ Dosing Scheme │   11/1   │   11/8   │   11/15  │   11/22  │

├───────────────┼──────────┼──────────┼──────────┼──────────┤

│       1       │  Group 1 │  Group 1 │  Group 2 │  Group 2 │

│               │ Period 1 │ Period 2 │ Period 1 │ Period 2 │

├───────────────┼──────────┼──────────┼──────────┼──────────┘

│       2       │  Group 1 │  Group 1 │          │

│               │ Period 1 │ Period 2 │          │

│               │          │  Group 2 │  Group 2 │

│               │          │ Period 1 │ Period 2 │

└───────────────┴──────────┴──────────┴──────────┘

It’s interesting that the FDA stated:

1. Both Dosing Schemes are acceptable to the Division of Bioequiva-
lence.

With the second scheme you’ll have the entire bunch of subjects at the clinical site on the second day. That’s bizarre; I don’t get it. If the CRO is large enough, why deal with two groups at all?

I would not bother about #1–8 and rather concentrate on

9. If ALL of the following criteria are met, it may not be necessary to
include Group-by-Treatment in the statistical model:

the clinical study takes place at one site;
all study subjects have been recruited from the same enrollment pool,
all of the subjects have similar demographics;
all enrolled subjects are randomly assigned to treatment groups at study outset.

In this latter case, the appropriate statistical model need include only the factors Sequence, Period, Treatment, and Subject (nested within Sequence).

❝ Also, in PHX winnonlin, should partial test or sequential test the best approach to look for all the stat test results (eg. Group, treatment, period effect)? I tend to go with partial test as it is tested independent of order but not sure if I am correct.

‘Partial Tests’ are expected to agree with SAS’ Type III LSMs in most of cases (whereas ‘Sequential Tests’ ≡ SAS’ Type I). See the “Phoenix User’s Guide” Table 17-13 (p448–50 = p478–80 of the PDF).

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Helmut Schütz

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Complete thread:

Phoenix WNL to handle 2x2 crossover study with multip group zan 2014-06-27 23:29
- Phoenix WNL to handle 2x2 crossover study with multip group ElMaestro 2014-06-28 23:23
- Group effect commonly not relevant Helmut 2014-06-30 16:55
  - Group effect in 2x2 BE study zan 2014-06-30 19:18
    - Group effect in 2x2 BE study ElMaestro 2014-06-30 20:36
    - To pool or not to pool Helmut 2014-06-30 20:51
      - To pool or not to pool zan 2014-06-30 21:02
        
        To pool or not to pool Helmut 2014-06-30 21:38
        
        To pool or not to pool zan 2014-06-30 21:46
        
        To pool or not to pool Helmut 2014-06-30 22:22
        
        To pool or not to pool zan 2014-07-01 01:15
        
        Partial vs. sequential tests in WNLHelmut 2014-07-01 12:26
        
        Partial vs. sequential tests in WNL zan 2014-07-01 18:03
        
        Loosing patience Helmut 2014-07-01 18:23
        
        To pool or not to pool ElMaestro 2014-06-30 22:11
        
        To pool or not to pool zan 2014-07-01 01:18
        To pool or not to pool zan 2014-07-02 19:56
        
        To pool or not to pool ElMaestro 2014-07-03 00:17
        
        To pool or not to pool zan 2014-07-03 00:36
        
        sequence- / period effect #666 Helmut 2014-07-03 10:05
  - Group effect commonly not relevant AngusMcLean 2014-07-06 16:19
    - Group effect commonly not relevant Helmut 2014-07-06 20:32
      - Group effect commonly not relevant AngusMcLean 2014-07-06 22:52
        
        Group effect commonly not relevant Helmut 2014-07-06 23:57
        
        PHX: Parameter mapping AngusMcLean 2014-07-07 15:04
        
        PHX: Parameter mapping Helmut 2014-07-07 15:45
        
        PHX: Parameter mapping Shuanghe 2014-07-07 17:35
        
        Great hint! Helmut 2014-07-07 17:54
        PHX: Parameter mapping AngusMcLean 2014-07-07 20:49
        
        PHX: Parameter mapping AngusMcLean 2014-07-07 18:46