Intra (within) centre validity for C/D ratio (direct clinical and photographic measurements)
| Groups compared | No | Mean difference | 95% CI for mean difference | SD | 95% TL | TL as % of range | Crude ICC | Adjusted ICC |
|---|---|---|---|---|---|---|---|---|
| C/D ratio: | ||||||||
| RCRSv Obs 1 R | 381 | −0.15 | −0.14, −0.16 | 0.14 | 0.27 | 33 | −0.04 | 0.39 |
| RCRSv Obs 1 L | 384 | −0.15 | −0.14, −0.16 | 0.15 | 0.28 | 40 | 0.10 | 0.44 |
| RCRSv Obs 2 R | 381 | −0.15 | −0.13, −0.17 | 0.15 | 0.30 | 40 | 0.12 | 0.38 |
| RCRSv Obs 2 L | 384 | −0.10 | −0.08, −0.12 | 0.16 | 0.31 | 32 | 0.21 | 0.42 |
| Obs 1v Obs 2 R | 381 | 0.05 | 0.04, 0.06 | 0.12 | 0.23 | 38 | 0.34 | 0.38 |
| Obs 1v Obs 2 L | 384 | 0.05 | 0.03, 0.07 | 0.15 | 0.30 | 32 | 0.24 | 0.25 |
RCRS = research clinic reference standard observation; Obs 1 = stereo photograph assessment by first observer; Obs 2 = Stereo photograph assessment by second observer; R = right eye; L = left eye; SD = standard deviation of paired differences; CI = confidence interval (for the mean); TL = tolerance limit for change; ICC = intraclass correlation coefficient.