Table 2 Detection rates with 95% confidence intervals (CI), by patient, for manual and automated “disease/no disease” grading for each of the grades assigned by the reference standard, with frequency of occurrence of each grade as a percentage of the total 6722 patients.

Grades assigned by reference standard	Frequency of occurrence (%)	Manual: by patient		Automated: by patient
		“Disease/no disease” grading detection rate (CI)	Missed cases	“Disease/no disease” grading detection rate (CI)	Missed cases
R1 (Mild background retinopathy)	24.4	80.9% (78.9–82.7) 1326/1640	314	85.9% (84.1–87.5) 1408/1640	232
M1 (Observable maculopathy)	1.1	98.7% (92.9–99.8) 75/76	1	97.4% (90.9–99.3) 74/76	2
R2 (Observable background retinopathy)	0.1	100% (67.6–100) 8/8	0	100% (67.6–100) 8/8	0
M2 (Referable maculopathy)	2.7	99.4% (96.9–99.9) 178/179	1	97.2% (93.6–98.8) 174/179	5
R3 (Referable background retinopathy)	0.6	97.4% (86.8–99.5) 38/39	1	100% (91.0–100) 39/39	0
R4 (Proliferative retinopathy)	0.4	100% (87.9–100) 28/28	0	100% (87.9–100) 28/28	0
R6 (Technical failure)	8.2	95.7% (93.6–97.1) 529/553	24	99.8% (99.0–100) 552/553	1