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Table 2 Estimates of sample size for primary and secondary outcomes

From: Research protocol: Management of obesity in patients with low health literacy in primary health care

Outcome Intra-cluster correlation coefficient Design effect (30 patients per practice) Effect size/different proportions Sample size estimate for each group
Advice on diet 0.051 2.48 25% 170
Advice on physical activity 0.035 2.02 25% 140
Referral/attendance diet 0.026 1.75 25% 115
Referral/attendance physical activity 0.011 1.32 25% 80
Mean health literacy score 0.014 1.41 0.4 140
Mean diet score 0.001 1.03 0.4 115
Mean physical activity score 0.018 1.52 0.4 150
Mean BMI 0.038 2.10 0.5 135