Table 2 Intraclass correlation coefficients by time between sample donation (years) and by season (NSMSC and NYUWHS)
From: Circulating levels of 25-hydroxyvitamin D and risk of breast cancer: a nested case-control study
NSMSC | NYUWHS | |||
|---|---|---|---|---|
Number of subjects | ICC (95% CI) | Number of subjects | ICC (95% CI) | |
Alla | 700 | 0.65 (0.61, 0.69) | 1,168 | 0.78 (0.76, 0.80) |
Allb | 700 | 0.71 (0.67, 0.74) | 1,168 | 0.78 (0.76, 0.80) |
Time between samplesb, years | ||||
≤ 1 | 393 | 0.80 (0.76, 0.83) | ||
> 1-2 | 146 | 0.79 (0.71, 0.84) | 325 | 0.81 (0.77, 0.84) |
> 2-3 | 139 | 0.81 (0.75, 0.86) | 208 | 0.80 (0.75, 0.84) |
> 3-5 | 196 | 0.71 (0.63, 0.73) | 214 | 0.74 (0.67, 0.79) |
> 5-8 | 113 | 0.56 (0.42, 0.68) | ||
> 8-11.7 | 106 | 0.63 (0.51, 0.74) | ||
Seasonsa | ||||
Both samples in winter | 148 | 0.74 (0.66, 0.81) | 266 | 0.78 (0.72, 0.82) |
Both samples in summer | 53 | 0.79 (0.67, 0.88) | 210 | 0.81 (0.76, 0.85) |
One sample in winter, one in summer | 92 | 0.47 (0.29, 0.61) | 68 | 0.66 (0.50, 0.77) |