Table 2.

Progression of Retinopathy between the End of the DCCT and after Four Years of the EDIC Study, According to the DCCT Treatment Group.^*

Level of Retinopathy at End of DCCT	NO. of PATIENTS†	Progression of Retinopathy‡	Odds Reduction (95% CI)§	P Value¶
		percent
All levels			75 (64-83)	<0.001
Conventional therapy	581	21
Intensive therapy	596	6
No retinopathy			66 (26-84)	0.006
Conventional therapy	109	16
Intensive therapy	173	6
Microaneurysms only			76 (49-88)	<0.001
Conventional therapy	184	14
Intensive therapy	233	4
Mild nonproliferative retinopathy			83 (60-93)	<0.001
Conventional therapy	178	19
Intensive therapy	132	4
Moderate nonproliferative retinopathy or worse			60 (18-80)	0.012
Conventional therapy	110	42
Intensive therapy	58	22
Adjusted ‖			72 (59-81)	<0.001

^*DCCT denotes Diabetes Control and Complications Trial, EDIC Epidemiology of Diabetes Intervention and Complications, and CI confidence interval.

^†Patients who underwent scatter photocoagulation during the DCCT were excluded from the analysis (22 patients in the conventional-therapy group and 9 in the intensive-therapy group). The numbers of patients in each group and stratum reflect the effect of the original DCCT therapy (e.g., more patients in the intensive-therapy group than in the conventional-therapy group were free of retinopathy at the end of the DCCT).

^‡Progression was defined as an increase of at least three steps between the end of the DCCT and year 4 of the EDIC study. Patients who underwent scatter photocoagulation after the DCCT were counted as having progressive retinopathy.

^§The odds reduction is for intensive therapy as compared with conventional therapy.

^¶P values were calculated by the likelihood-ratio test.

^‖Logistic-regression analysis was performed with adjustment for the severity of retinopathy at the end of the DCCT according to the Early Treatment Diabetic Retinopathy Study categories.