Table 1.

Characteristics of Cohort at Beginning of Each Wisconsin Epidemiologic Study of Diabetic Retinopathy Examination.

Factor	Baseline N=996	4-Year N=891	10-Year N=784	14-Year N=654	25-Year N=426
Mean age, year	29	32	37	41	50
% Males	49	49	49	50	48
Mean glycosylated hemoglobin A1, %	10.8	10.1	10.0	9.5	8.1
Mean systolic blood pressure, mmHg	124.6	123.2	126.1	126.8	132.8
Mean diastolic blood pressure, mmHg	78.7	77.2	76.2	74.5	73.2
% Hypertension	22	23	29	34	53
% Proteinuria	21	23	27	23	26
% Education level, college graduate	23	26	30	30	32
Mean Duncan’s Socioeconomic Index	61	61	61	62	62
% Proliferative diabetic retinopathy	23	28	41	43	48
% Macular edema	10	13	21	23	24
% Photocoagulation*	15	21	31	37	43
% Visual impairment	8	10	9	8	7

^*Photocoagulation= panretinal, macular grid and/or focal photocoagulation;