ABSTRACT
Objective To establish a risk prediction model of diabetic retinopathy (DR) for type 2 diabetic patients (T2DM).Methods A total of 315 T2DM patients (600 eyes) were enrolled in the study.There were 132 males (264 eyes) and 183 females (366 eyes).The mean age was (67.28± 12.17) years and the mean diabetes duration was (10.86 ± 7.81) years.The subjects were randomly assigned to model group and check group,each had 252 patients (504 eyes) and 63 patients (126 eyes) respectively.Some basic information including gender,age,education degree and diabetes duration were collected.The probable risk factors of DR including height,weight,blood pressure,fasting glucose,glycosylated hemoglobin (HbAlc),blood urea,serum creatinine,uric acid,triglyceride,total cholesterol,high-density lipoprotein,low density lipoprotein cholesterol and urinary protein.The fundus photograph and the axial length were measured.Multivariate logistic regression was used to analyze the correlative factors of DR and establish the regression equation (risk model).Receiver operating characteristic (ROC) curves were used to determine the cut-off point for the score.The maximum Youden Index was used to determine the threshold of the equation.The check group was used to check the feasibility of the predictive model.Results Among 504 eyes in the model group,170 eyes were DR and 334 eyes were not.Among 126 eyes in the check group,45 eyes were DR and 81 eyes were not.Multivariate logistic regression analysis revealed that axial length [β=-0.196,odds ratio (OR)=0.822,P＜0.001],age (β=-0.079,OR=0.924,P＜0.001),diabetes duration (β=0.048,OR=1.049,P=0.001),HbAlc (β=0.184,OR=1.202,P=0.020),urinary protein (β=1.298,OR=3.661,P＜0.001) were correlated with DR significantly and the simplified calculation of the score of DR were as follows:P=7.018-0.196X 1-0.079X2+0.048X3+0.148X4+ 1.298X5 (X1=axial length,X2=age,X3=diabetes duration,X4=glycosylated hemoglobin,X5=urinary protein).The area under the ROC curve for the score DR was 0.800 and the cut-offpoint of the score was-1.485.The elements of the check group were substituted into the equation to calculate the scores and the scores were compared with the diagnostic threshold to ensure the patients in high-risk of DR.The result of the score showed 84％ sensitivity and 59％ specificity.ROC curve for the score to predict DR was 0.756.Conclusion Axial length,age,diabetes duration,HbA1c and urinary protein have significant correlation with DR.The sensitivity and specificity of the risk model to predict DR are 84.0％ and 59.0％ respectively.The area under the ROC curve was 0.756.