Risk factor analysis and clinical decision tree model construction for diabetic retinopathy in Western China

Table 2 Variable assignment

Variable	Assignment
Sex	0 = male
	1 = female
Age	0 = age < 60 years
	1 = age ≥ 60 years
Diabetes duration	0 = duration < 10 years
	1 = duration ≥ 10 years
Blood pressure	0 = normal (SBP < 140 mmHg and/or DBP < 90 mmHg)
	1 = abnormal (SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg)
BMI	0 = normal (BMI < 24 kg/m2)
	1 = overweight (24 kg/m2 ≤ BMI < 28 kg/m2)
	2 = obesity (BMI ≥ 28 kg/m2)
Waist circumference	0 = normal (male < 90 cm, female < 85 cm)
	1 = increased (male ≥ 90 cm, female ≥ 85 cm)
Glu0	0 = well controlled (Glu0 ≤ 7.0 mmol/L)
	1 = poorly controlled (Glu0 > 7.0 mmol/L)
HbA1c	0 = well controlled (HbA1c < 7%)
	1 = generally controlled (7% ≤ HbA1c < 8%)
	2 = poorly controlled (HbA1c ≥ 8%)
Blood lipids	0 = normal
	1 = dyslipidemia (met any of the following criteria: TG ≥ 2.26 mmol/L; TC ≥ 6.26 mmol/L; LDL ≥ 4.14 mmol/L; HDL < 1.04 mmol/L)
UA	0 = normal
	1 = hyperuricemia (UA > 420 μmmol/L)
CKD stage	0 = G1 (eGFR ≥ 90 mL/min)
	1 = G2 (eGFR = 60-89 mL/min)
	2 = G3 (eGFR = 30-59 mL/min)
	3 = G4 (eGFR = 15-29 mL/min)
	4 = G5 (eGFR < 15 mL/min)

SBP: Systolic blood pressure; DBP: Diastolic blood pressure; BMI: Body mass index; Glu0: Fasting blood glucose; HbA1c: Glycated hemoglobin A1c; Trig: Triglyceride; Chol: Cholesterol; LDL-C: Low-density lipoprotein Chol; HDL-C: High-density lipoprotein Chol; UA: uric acid; CKD: Chronic kidney disease; G: Grade; eGFR: Estimated glomerular filtration rate.