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 |