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Table 4 Power and sample size justification

From: Dietary approaches to treat MS-related fatigue: comparing the modified Paleolithic (Wahls Elimination) and low saturated fat (Swank) diets on perceived fatigue in persons with relapsing-remitting multiple sclerosis: study protocol for a randomized controlled trial

Variable

Within Study Groups

Between Study Groups at Last Visit

MMCD

SD

Correlation

MMCD

SD Group A

SD Group B

Power is ≥0.85 for the primary outcome

 FSS-9

1.2–2.0

1.1–1.4

0.6

0.7 [35]

0.9

1.1

Power is ≥0.90 for secondary outcomes

 MSQOL-54

      

 PHC

11.5

16.0

0.6

17.0

17.0

19.0

 MHC

12.0

17.0

0.5

18.0

18.0

19.0

 6 min walk test

35

50.0

0.5

45.0

45.0

50.0

 Timed 25 ft walk

2.9

4.0

0.5

4.0

4.0

4.3

 9 hole peg test

5.5

8.0

0.5

8.0

8.1

8.3

 PASATa

4.2

6.0

0.5

5.8

6.0

6.3

  1. Abbreviations: FSS Fatigue Severity Scale, MSQOL-54 Multiple Sclerosis Quality of Life 54, PHC MSQOL-54 physical health composite score, MHC MSQOL-54 mentalhealth composite score, PASAT Paced Auditory Serial Addition Test, MMCD Minimun Mean Clinical Difference
  2. aPower and sample size calculations based on PASAT. Per NMSS, SDMT-O replaces the PASAT measure in this study