TABLE 3

Covariate associations in multivariate Cox proportional hazards model for time to severe retinopathy

CovariateHR95% CIP
Secondary intervention vs. primary prevention cohort2.341.42–3.858.6 × 10−4
Intensive vs. conventional treatment0.820.42–1.590.56
Cohort-by-treatment interaction0.930.45–1.910.85
Age at diagnosis (years)0.25*
            Contrast between age of diagnosis at 30 vs. 20 years1.180.86–1.630.30
Type 1 diabetes duration (years) at DCCT baseline<10−4*
            Contrast between 3.5 and 1.5 years of diabetes duration1.260.98–1.620.071
            Contrast between 12 and 6 years of diabetes duration3.082.34–4.05<10−4
Female vs. male sex0.730.54–0.970.032
BMI: 10% increase (25.7 vs. 23.4 kg/m2)§0.990.88–1.100.79
Mean arterial blood pressure: 10% increase (95.1 vs. 85.6 mmHg)§1.001.00–1.000.66
Triglyceride: 10% increase (90.0 vs. 81.8 mg/dl)§1.020.98–1.050.37
HDL cholesterol: 10% increase (55.4 vs. 50.4 mg/dl)§1.030.96–1.100.36
Total cholesterol: 10% increase (194.9 vs. 176.2 mg/dl)§0.990.91–1.080.82
A1C at DCCT eligibility: 10% increase (9.94 vs. 9.04%)1.151.12–1.190.0025
Smoking at DCCT baseline (pack/year)0.970.94–0.990.0051
Updated mean A1C measured during DCCT/EDIC: 1 unit increase (8.0 vs. 7.0%)2.632.22–3.11<10−4
Updated hypertension indicator during DCCT/EDIC1.751.26–2.438.9 × 10−4
  • Sample size = 1,367.

  • * P value from 2 d.f. Wald test for joint contribution of linear and quadratic trend.

  • P value from 1 d.f. Wald test derived from linear contrast of linear and quadratic trend.

  • § Ten percent increase from the mean value at DCCT baseline.