Table 2.
Nineteen Features Used for SVM.
| Features | Definition | |
|---|---|---|
| Disease name (frequency) | T2DM codes as main diagnosis | E11x (ICD-10 code) |
| T1DM codes | Disease control number,34 including T1DM | |
| Malnutrition-related-DM | E12x (ICD-10 code) | |
| Secondary DM | E13x (ICD-10 code) | |
| Unspecified DM as main diagnosis | E14x (ICD-10 code) | |
| Slowly progressive insulin-dependent diabetes mellitus (SPIDDM) | Disease control number,34 including SPIDDM. (If one ICD-10 code corresponds to different disease names in Japanese, each disease name has its own disease control number. We could have performed a more detailed coding using the disease control number than by using ICD-10 alone.) | |
| Medication (frequency) | Insulin | 24924x, 24925x, 24926x (National Health Insurance Drug List) |
| T2DM medication | 396x (National Health Insurance Drug List) | |
| Medication with a function of rise in blood glucose | The medications or injections that have descriptions about hyperglycemia as a side effect in the package inserts. (The National Health Insurance Drug List provides the codes of drugs used in Japan.) | |
| Injection with a function of rise in blood glucose | ||
| Laboratory tests (maximum value) | Random glucose | There were no criteria for distinguishing random blood glucose levels and fasting blood glucose levels in HL7 storage at UT Hospital. We thus assumed that all blood glucose levels were random blood glucose levels. |
| Glycoalbumin | ||
| HbA1c (J) | HbA1c (J) was the HbA1c standard used in Japan until March 2012, and HbA1c (J) 6.1% is equivalent to HbA1c 6.5%. | |
| HbA1c | ||
| GAD antibody | ||
| IA2 antibody | ||
| 125I-insulin biding ratio | ||
| (minimum value) | C-peptide |
We selected features that are correlated with T2DM and other subtypes of DM.