Performances of selected algorithms*
| Algorithm description | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) |
| EMR algorithms | ||||
| EMRTree† | 80.6 (75.9 to 87.2) | 99.8 (99.7 to 100) | 94.9 (92.3 to 98.7) | 99.3 (99.1 to 99.5) |
| EMRForest‡ | 83.1 (77.1 to 88.1) | 99.8 (99.6 to 99.9) | 93.1 (88.3 to 96.) | 99.4 (99.1 to 99.6) |
| EMRRule 1: definite T1D CPP + no non-insulin, non-metformin glycemic agent | 77.9 (71.5 to 83.6) | 99.5 (99.3 to 99.7) | 86.4 (80.4 to 91.1) | 99.2 (98.9 to 99.4) |
| EMRRule 2: definite T1D CPP or pump | 81.5 (75.4 to 86.7) | 99.2 (98.9 to 99.4) | 79.1 (72.8 to 84.5) | 99.3 (99 to 99.5) |
| EMRRule 3: definite T1D CPP + no T2D CPP | 76.9 (70.4 to 82.6) | 99.4 (99.1 to 99.6) | 82 (75.6 to 87.2) | 99.1 (98.8 to 99.4) |
| EMRRule 4: (definite T1D CPP + insulin + no non-insulin, non-metformin glycemic agent) or (possible T1D CPP + age at index <45) | 81 (74.8 to 86.3) | 97.5 (94.6 to 99.1) | 96.3 (92.2 to 98.6) | 86.3 (81.7 to 90.2) |
| EMRRule 5: definite T1D CPP | 77.9 (71.5 to 83.6) | 98.8 (96.4 to 99.7) | 98.1 (94.4 to 99.6) | 84.6 (79.9 to 88.7) |
| EMRRule 6: definite T1D CPP or BMI <25 | 85.6 (79.9 to 90.2) | 89.6 (85 to 93.1) | 87 (81.4 to 91.4) | 88.5 (83.8 to 92.2) |
| Administrative data algorithms | ||||
| AdminTree† | 61.4 (57.5 to 71.3) | 99.2 (99.0 to 99.5) | 73.9 (70.1 to 83.5) | 98.6 (98.3 to 99.0) |
| AdminForest‡ | 58.0 (50.7 to 65.0) | 99.3 (99.0 to 99.5) | 74.8 (67.1 to 81.5) | 98.4 (98.1 to 98.8) |
| AdminRule 1: pediatric diabetes or pump or T1D DKA | 58.5 (51.2 to 65.5) | 99.3 (99.1 to 99.5) | 76.5 (68.9 to 83.1) | 98.5 (98.1 to 98.8) |
| AdminRule 2: pediatric diabetes or pump | 51.3 (44.0 to 58.5) | 99.5 (99.3 to 99.7) | 79.4 (71.2 to 86.1) | 98.2 (97.8 to 98.5) |
| AdminRule 3: (diabetes incidence <30 + (pediatric diabetes or any DKA)) or pump or T1D DKA | 61.5 (54.3 to 68.4) | 99.3 (99.0 to 100) | 75.9 (68.5 to 100) | 98.6 (98.2 to 98.9) |
| AdminRule 4: diabetes incidence <30 or pump or any DKA | 80.0 (73.7 to 85.4) | 96.7 (96.2 to 97.2) | 47.6 (42.0 to 53.1) | 99.2 (99.0 to 99.5) |
| AdminRule 5: diabetes incidence <30 or (diabetes incidence <40 and no T2D) or pump or any DKA | 91.3 (86.4 to 94.8) | 92.6 (91.8 to 93.3) | 31.5 (27.7 to 35.5) | 99.6 (99.4 to 99.8) |
| Combined EMR and administrative data algorithms | ||||
| EMR+AdminTree† | 80.9 (76.5 to 87.6) | 99.9 (99.8 to 100) | 95.7 (93.1 to 99.0) | 99.3 (99.0 to 99.5) |
| EMR+AdminForest‡ | 88.2 (82.8 to 92.4) | 99.8 (99.7 to 100) | 95.0 (90.8 to 97.7) | 99.6 (99.3 to 99.7) |
| EMR+AdminRule 1: insulin + no non-insulin, non-metformin glycemic agent + (definite T1D CPP or pump or pediatric diabetes) | 87.2 (81.7 to 91.5) | 99.9 (99.7 to 100) | 96.6 (92.7 to 98.7) | 99.5 (99.3 to 99.7) |
| EMR+AdminRule 2: insulin + no non-insulin, non-metformin glycemic agent + (pediatric diabetes or pump) | 51.3 (44.0 to 58.5) | 100 (99.9 to 100) | 98 (93.1 to 99.8) | 98.2 (97.8 to 98.5) |
| EMR+AdminRule 3: bolus insulin + no non-insulin, non-metformin glycemic agent + (definite T1D CPP or pump or pediatric diabetes) | 79.5 (73.1 to 84.9) | 99.9 (99.7 to 100) | 96.3 (92.1 to 98.6) | 99.2 (99 to 99.5) |
| EMR+AdminRule 4: definite T1D CPP + insulin + no non-insulin, non-metformin glycemic agent | 77.4 (70.9 to 83.1) | 99.9 (99.8 to 100) | 96.8 (92.7 to 99) | 99.2 (98.9 to 99.4) |
*EMRPC reference standard included 5402 individuals (195 with T1D, 5207 with T2D).
†Classification tree estimates were optimism-adjusted.
‡Random forest used rfimpute for missing data (age at diabetes incidence, eGFR and BMI).
BMI, body mass index; CPP, Cumulative Patient Profile; DKA, diabetic ketoacidosis; eGFR, estimated glomerular filtration rate; EMR, electronic medical record; EMRPC, Electronic Medical Records Primary Care; NPV, negative predictive value; PPV, positive predictive value; T1D, type 1 diabetes; T2D, type 2 diabetes.