Table 1b. Cross-tabulation of grades between screening, clinical examination, and imaging (1580 eyes).

Screening	Clinical				Combined grade				Imaging alone
	R0	R1	R2	R3	R0	R1	R2	R3	R0	R1	R2	R3
R0	50	18	3	0	42	22	4	0	47	20	2	2
R1	137	732	118	5	86	675	214	9	122	540	319	17
R2	19	109	210	15	10	82	253	10	9	90	235	24
R3	6	25	39	71	4	15	44	76	7	23	43	72
Total	210	884	370	91	142	794	515	95	185	673	599	115
	κ=0.446				κ=0.314				κ=0.449

Abbreviations: R0, no DR; R1, mild NPDR; R2, moderate–severe DR; R3, proliferative DR.