Accuracy of trained rural ophthalmologists versus non-medical image graders in the diagnosis of diabetic retinopathy in rural China.

Background/aims: To determine the diagnostic accuracy of trained rural ophthalmologists and non-medical image graders in the assessment of diabetic retinopathy (DR) in rural China. Methods: Consecutive patients with diabetes mellitus were examined from January 2014 to December 2015 at ten county-level facilities in rural Southern China. Trained rural ophthalmologists performed a complete eye examination, recording diagnoses using the United Kingdom National Diabetic Eye Screening Programme (NDESP) classification system. Two field, mydriatic, 45° digital photographs were made by nurses using NDESP protocols, and graded by trained graders with no medical background using the NDESP system. A fellowship-trained retina specialist graded all images in masked fashion and served as reference standard. Results: Altogether, 375 participants (mean age 60 +/-10 years, 48% men) were examined and 1277 images graded. Grader sensitivity (0•82-0•94 (median 0•88)) and specificity (0•91-0•99 (median 0•98)), reached or exceeded NDESP standards (sensitivity 80%, specificity 95%) in all domains except specificity detecting any DR. Rural ophthalmologists’ sensitivity was 0•65-0•95 (median 0•66) and specificity 0•59-0•95 (median 0•91). There was strong agreement between graders and the reference standard (kappa=0•84-0•87, P<0•001) and weak-moderate agreement between rural doctors and the reference (kappa= 0•48-0•64, P<0•001). Conclusion: This is the first study of diagnosticaccuracy in DR grading among non-medical graders orophthalmologists in low-income and middle-incomecountries. Non-medical graders can achieve highlevels of accuracy, whereas accuracy of trained ruralophthalmologists is not optimal.