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Table 3 Sample size calculation

From: Acupuncture for post anaesthetic recovery and postoperative pain: study protocol for a randomised controlled trial

F tests:

ANOVA: Fixed effects, omnibus, one-way

Analysis:

A priori: Compute required sample size

Input:

Effect size f

 

= 0.4

α err probability

 

= 0.05

Power (1-β err probability)

 

= 0.8

Number of groups

 

= 3

Output:

Noncentrality parameter λ

 

= 10.5600000

Critical F

 

= 3.1428085

Numerator df

 

= 2

Denominator df

 

= 63

Total sample size

 

= 66

 

Actual power

 

= 0.8

  1. A priori analysis as calculated and exported by G*Power (Version 3.1.3, University of Düsseldorf, Germany), anticipating a small to medium effect size f = 0.4, the α-error = 0.05 and the power = 0.8.
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Trials

ISSN: 1745-6215