Table 4

Power calculation In order to have 80% or 90% power for the analysis of reduction in function scores (change) we would need (per study arm)

m1-m0


0.20

0.30

0.40

0.50

80% power

298

133

75

48

90% power

399

177

100

64


Martin et al. BMC Musculoskeletal Disorders 2005 6:2   doi:10.1186/1471-2474-6-2

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