Study protocol
Early intervention for adolescents with Patellofemoral Pain Syndrome - a pragmatic cluster randomised controlled trial
BMC Musculoskeletal Disorders 2012, 13:9 doi:10.1186/1471-2474-13-9
Study protocol
Study protocol
BMC Musculoskeletal Disorders 2012, 13:9 doi:10.1186/1471-2474-13-9
Wrong power calculation and analysis
David J Torgerson (2012-03-01 15:32) York University
You are doing a cluster randomised controlled trial. However, your sample size is incorrect: you have not adjusted for clustering. Also your analysis strategy is incorrect: again you need to adjust for clustering. Even if you did the adjustment you only have 4 clusters, which is insufficient cluster replication. You need to increase the number of clusters to at least 8 and recalculate your sample size.
Competing interests
None
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