Bioequivalence and Bioavailability Forum • TOST != treatment effect

TOST != treatment effect [Power / Sample Size]

posted by mittyri – Russia, 2025-02-20 14:13 (118 d 14:17 ago) – Posting: # 24367
Views: 3,200

Hi BEQool,

❝ ❝ A significant treatment effect will show up in all studies where the confidence interval does not include unity.

❝ Is this always true? Or better, in which cases this isnt true? What could be the reason? Namely I saw a case with lower limit of 90% CI of 102.3% and p-value for treatment effect of 0.055.

❝ So based on 90% CI, treatment effect should be significant but here it isnt :confused:

I guess it is not.
The TOST procedure is designed for equivalence testing and uses two one‑sided tests at the 5% level (each tail), which, when combined, yield a 90% CI. In contrast, a standard test for a treatment effect (ANOVA based) is typically a two‑sided test at the 5% significance level. These two approaches, while related, test slightly different hypotheses.

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Kind regards,
Mittyri

Complete thread:

Significance The Outlaw Torn 2012-11-20 07:56 [Power / Sample Size]
- Significance ElMaestro 2012-11-20 08:17
  - Significance The Outlaw Torn 2012-11-20 08:55
    - Quality vs. Clinical ElMaestro 2012-11-20 09:04
- Sample size? Helmut 2012-11-20 20:10
  - Sample size? The Outlaw Torn 2012-11-21 07:52
  - Sample size? The Outlaw Torn 2012-11-22 10:55
    - Sample size, ratio, CV ↔ power Helmut 2012-11-22 13:35
      - Sample size, ratio, CV ↔ power The Outlaw Torn 2012-11-23 14:47
      - Sample size, ratio, CV ↔ power BEQool 2025-01-31 13:12
        
        TOST != treatment effectmittyri 2025-02-20 13:13
        Sample size, ratio, CV ↔ power zizou 2025-02-21 13:40
        
        Not vice versa mittyri 2025-02-22 21:08
        
        Not vice versa? zizou 2025-02-24 11:02
        
        Not vice versa? mittyri 2025-02-25 06:12
- Sample size calculation using Marzo and Balant method kumarnaidu 2013-01-31 07:48
  - Marzo / Balant formula d_labes 2013-01-31 10:05
    - Marzo / Balant formula kumarnaidu 2013-01-31 10:54
      - Marzo / Balant formula kumarnaidu 2013-02-04 05:48
        
        Marzo / Balant formula for parallel groups d_labes 2013-02-04 08:44