Table 3.
Estimated Intra-class correlations (ICC) 1 and calculated sample sizes 2 for variables measured daily over the entire study
| Variable | Estimated ICC 1 | Estimated sample size 2 |
|---|---|---|
| Feeling today |
0.35 |
950 |
| Hours slept |
0.34 |
941 |
| Ill past 24 hours |
0.16 |
828 |
| Whole body soreness |
0.41 |
1011 |
| Art soreness |
0.46 |
1075 |
| Leg soreness |
0.40 |
1000 |
| Confidence |
0.58 |
1301 |
| Anxiety |
0.56 |
1254 |
| Fatigue | 0.32 | 924 |
1ICC was calculated as within subject variance/total variance within a linear regression random effects model.
2Sample sizes calculated using matched case–control design and the following parameter values: alpha = 0.05, power = 0.8, 10:1 ratio of controls to cases, risk of exposure (categorized dichotomously) in controls at 0.3, and an increased risk of exposure in cases at 20%.