Table 3

Inter (between) centre agreement analysis (direct clinical measurements with patients in attendance)

Groups comparedNoMean difference95% CI for
mean difference
TL as %
of range
Crude ICCAdjusted ICC
C/D ratio:
RCRSv HES R3600.100.08,
RCRSv HES L3580.050.03,
RCRSv CO R3600.050.03,
RCRSv CO L3580.100.08,
HESv CO R360−0.05−0.03, −
HESv CO L3580.050.03,
RCRS2v HES R3882.41.95, 2.854.508.8260.330.44
RCRS2v HES L3882.82.36, 3.244.468.7260.340.48
RCRS2v CO R3882.01.57, 2.434.368.6220.450.52
RCRS2v CO L3882.21.75, 2.654.488.8210.420.50
HESv CO R3880.4−0.05, 0.854.508.8230.450.45
HESv CO L3880.60.13, 1.074.699.2270.400.40
RCRS1v CO1 R366−0.4−1.53, 0.7311.0322290.640.64
RCRS1v CO1 L3660.1−0.93, 1.1310.1220210.730.73
HESv CO R2871.1−0.38, 2.5812.8025330.540.55
HESv CO L2870.7−0.80, 2.2012.9525270.610.61
RCRSMv HES R3080.6−0.59, 1.6910.6621280.640.64
RCRSMv HES L3050.3−1.03, 1.6311.8823250.610.61
RCRSMv COM R1700.8−0.32, 1.927.4415210.800.80
RCRSMv COM L1700.2−0.87, 1.277.3314170.840.84
  • RCRS = research clinic reference standard observation; RCRS1 = research clinic reference standard first observation; RCRS2 = research clinic reference standard second observation; RCRSM = mean research clinic reference standard observation; HES = hospital eye service assessment; CO = community optometric assessment; CO1 = community optometric first assessment (where repeated assessments made); COM = mean community optometric assessment; 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.