Table 3

Risk classifications defined by RPA for cohorts 1, 2, and 3

CohortClassClassification risk factors (thresholds)5-year riskHazard ratio (95% CI)
A: Cohort 1: single autoantibody: Outcome, progression to persistent multiple positive autoantibodies
 RPA classificationLow riskAge >16 years and GAD65Ab titer (GAD65) ≤0.126
Intermediate riskAge ≤16 years and GAD65Ab titer (GAD65) ≤0.126
High riskGAD65Ab titer (GAD65) >0.126
 5-year risk*Low risk11%Reference
Intermediate risk29%2.71 (1.62–4.53)
High risk45%4.68 (2.98–7.36)
B: Cohort 2: multiple autoantibodies: Outcome, progression to dysglycemia
 RPA classificationLow risk2-h glucose ≤110 mg/dL and IA-2A titer (ICA512) ≤0.025
Intermediate risk2-h glucose ≤110 mg/dL and IA-2A titer (ICA512) >0.025; or 2-h glucose >110 mg/dL and fasting C-peptide ≤1.235 ng/mL
High risk2-h glucose >110 mg/dL and fasting C-peptide >1.235 ng/mL
 5-year risk*Low risk28%Reference
Intermediate risk39%1.78 (1.37–2.32)
High risk51%2.68 (2.07–3.48)
C: Cohort 3: dysglycemia: Outcome, progression to T1D
 RPA classificationLow riskSingle autoantibody at dysglycemia and age >16 years at dysglycemia
Intermediate riskSingle autoantibody at dysglycemia and age ≤16 years at dysglycemia or multiple autoantibodies and peak C-peptide >8.35 ng/mL at dysglycemia
High riskMultiple autoantibodies and peak C-peptide ≤8.35 ng/mL and HbA1c ≤5.1 at dysglycemia
Very high riskMultiple autoantibodies and peak C-peptide ≤8.35 ng/mL and HbA1c >5.1 at dysglycemia
 5-year risk*Low risk9%Reference
Intermediate risk33%4.85 (2.95–7.95)
High risk62%9.05 (5.45–15.03)
Very high risk80%21.84 (13.40–35.59)
  • *Cumulative risk from Kaplan-Meier estimate.