Table 3.

Diagnostic analysis of non-mydriatic fundus images from diabetic patients and inter-grader agreement between a retinal specialist (RS) and four trained family physicians (FPs).

Variable	RS	FP1	FP2	FP3	FP4
Diabetic retinopathy
Absent (%)	231 (58.2)	289 (72.8)	278 (70)	234 (58.9)	280 (70.5)
Present (%)	166 (41.8)	108 (27.2)	119 (30)	163 (41.1)	117 (29.5)
Kappa (95% CI)		0.56 (0.48; 0.64)	0.69 (0.61; 0.76)	0.73 (0.66; 0.80)	0.71 (0.64; 0.78)
Sensitivity (95% CI)		58.2 (50.3; 65.8)	68.5 (60.8; 75.5)	83.6 (77.1; 88.9)	69.1 (61.4; 76)
Specificity (95% CI)		94.8 (91.1; 97.3)	97.4 (94.5; 99)	89.2 (84.5; 92.9)	98.7 (96.3; 99.7)
PPV (95% CI)		88.9 (81.4; 94.1)	95 (89.3; 98.1)	84.7 (78.2; 89.8)	97.4 (92.7; 99.5)
PNV (95% CI)		76.1 (70.8; 80.9)	81.3 (76.2; 85.7)	88.5 (83.7; 92.3)	81.8 (76.8; 86.1)
Severity
Absent (%)	231 (58.2)	289 (72.8)	278 (70)	234 (58.9)	280 (70.5)
Treated (%)	15 (3.8)	15 (3.8)	14 (3.5)	20 (5)	14 (3.5)
Non-proliferative (%)	143 (36)	72 (18.1)	100 (25.2)	132 (33.2)	66 (16.6)
Proliferative (%)	8 (2)	21 (5.3)	5 (1.3)	9 (2.3)	37 (9.3)
Non-gradable (%)	0 (0)	0 (0)	0 (0)	2 (0.5)	0 (0.0)
Weighted kappa (95% CI)		0.51 (0.44; 0.59)	0.66 (0.59; 0.73)	0.69 (0.62; 0.76)	0.64 (0.58; 0.71)
Macular edema
Absent (%)	309 (77.8)	363 (91.4)	362 (91.2)	358 (90.2)	343 (86.4)
Present (%)	88 (22.2)	34 (8.6)	35 (8.8)	39 (9.8)	54 (13.6)
Kappa (95% CI)		0.33 (0.21; 0.44)	0.39 (0.28; 0.51)	0.37 (0.26; 0.48)	0.51 (0.40; 0.62)
Sensitivity (95% CI)		28.4 (19.3; 39)	33 (23.3; 43.8)	33 (23.3; 43.8)	47.7 (37; 58.6)
Specificity (95% CI)		97.1 (94.5; 98.7)	98.1 (95.8; 99.3)	96.8 (94.1; 98.4)	96.1 (93.3; 98)
PPV (IC 95%)		73.5 (55.6; 87.1)	82.9 (66.4; 93.4)	74.4 (57.9; 87)	77.8 (64.4; 88)
PNV (IC 95%)		82.6 (78.3; 86.4)	83.7 (79.5; 87.4)	83.5 (79.3; 87.2)	86.6 (82.5; 90)

CI, confidence interval; PPV, predictive positive value; PNV, predictive negative value.