Table 3

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

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 HES R	360	0.10	0.08, 0.12	0.17	0.33	39	0.43	0.52
RCRSv HES L	358	0.05	0.03, 0.07	0.16	0.32	33	0.46	0.48
RCRSv CO R	360	0.05	0.03, 0.07	0.17	0.33	39	0.42	0.44
RCRSv CO L	358	0.10	0.08, 0.12	0.19	0.36	44	0.36	0.46
HESv CO R	360	−0.05	−0.03, −0.07	0.18	0.35	39	0.47	0.50
HESv CO L	358	0.05	0.03, 0.07	0.18	0.35	44	0.50	0.54
IOP:
RCRS2v HES R	388	2.4	1.95, 2.85	4.50	8.8	26	0.33	0.44
RCRS2v HES L	388	2.8	2.36, 3.24	4.46	8.7	26	0.34	0.48
RCRS2v CO R	388	2.0	1.57, 2.43	4.36	8.6	22	0.45	0.52
RCRS2v CO L	388	2.2	1.75, 2.65	4.48	8.8	21	0.42	0.50
HESv CO R	388	0.4	−0.05, 0.85	4.50	8.8	23	0.45	0.45
HESv CO L	388	0.6	0.13, 1.07	4.69	9.2	27	0.40	0.40
VF:
RCRS1v CO1 R	366	−0.4	−1.53, 0.73	11.03	22	29	0.64	0.64
RCRS1v CO1 L	366	0.1	−0.93, 1.13	10.12	20	21	0.73	0.73
HESv CO R	287	1.1	−0.38, 2.58	12.80	25	33	0.54	0.55
HESv CO L	287	0.7	−0.80, 2.20	12.95	25	27	0.61	0.61
RCRSMv HES R	308	0.6	−0.59, 1.69	10.66	21	28	0.64	0.64
RCRSMv HES L	305	0.3	−1.03, 1.63	11.88	23	25	0.61	0.61
RCRSMv COM R	170	0.8	−0.32, 1.92	7.44	15	21	0.80	0.80
RCRSMv COM L	170	0.2	−0.87, 1.27	7.33	14	17	0.84	0.84

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.