Table 1.
Distribution of Each Predictor Variable among Probable Type 1 and Type 2 Diabetes Mellitus Cases in the MARS Data Seta
| Variable | Probable T1DM (n = 8,173) | Probable T2DM (n = 121,511) |
|---|---|---|
| Age at first entry into the MARS database, | ||
| years (mean, SD) | 44.2 (18.2) | 64.9 (14.8) |
| Missing, % (n) | 6.0 (487) | 10.7 (12,966) |
| Gender, % (n) | ||
| Male | 50.4 (4,118) | 47.3 (57,470) |
| Female | 48.5 (3,963) | 51.8 (63,000) |
| Missing | 1.1 (92) | 0.9 (1,041) |
| Race, % (n) | ||
| White | 76.0 (6,208) | 80.0 (97,288) |
| African American | 15.5 (1,268) | 12.8 (15,574) |
| Asian | 0.1 (10) | 0.2 (177) |
| Hispanic | 0.3 (22) | 0.2 (276) |
| Other | 0.9 (74) | 0.9 (1,079) |
| Missing | 17.2 (59) | 5.9 (7,117) |
| Inpatient insulin use, % (n) | 71.2 (5,819) | 51.2 (62,238) |
| Inpatient OHA use, % (n) | 2.4 (193) | 41.9 (50,911) |
| ICD-9 code of DM, % (n)b | ||
| T1DM only | 47.2 (3,858) | 0.2 (241) |
| T2DM or unspecified DM only | 0.5 (38) | 78.6 (95,525) |
| Both T1DM and T2DM | 24.5 (2,010) | 7.0 (8,493) |
| Missing | 27.7 (2,267) | 14.2 (17,252) |
| Age at first complicationc in the MARS database, years (mean, SD) | 48.2 (15.0) | 70.4 (12.1) |
| History of CABG or MI, % (n) | 6.8 (558) | 9.6 (11,686) |
| CABG | 3.8 (311) | 5.9 (7,215) |
| MI | 4.7 (380) | 6.0 (7,236 ) |
| Age at first CABG or MI in the MARS database, years (mean, SD) | 53.7 (14.4) | 71.6 (11.5) |
| CABG | 56.7 (13.9) | 72.1 (10.6) |
| MI | 51.8 (14.2) | 71.0 (12.1) |
| History of dialysis, % (n) | 2.9 (233) | 0.6 (679) |
| Age at first dialysis in the MARS database, years (mean, SD) | 41.1 (13.8) | 66.6 (13.2) |
| History of amputation, % (n) | 1.1 (90) | 0.4 (518) |
| Age at first amputation in the MARS database, years (mean, SD) | 48.2 (16.6) | 69.2 (12.8) |
| History of retinopathy, % (n) | 4.2 (345) | 0.7 (903) |
| Age at first retinopathy in the MARS database, years (mean, SD) | 50.2 (13.1) | 65.9 (12.0) |
| History of neuropathy, % (n) | 5.7 (466) | 2.6 (3,103) |
| Age at first neuropathy in the MARS database, years (mean, SD) | 51.2 (12.8) | 66.8 (12.6) |
| History of DKA, % (n) | 17.6 (1,435) | 0.2 (284) |
| History of hypoglycemic coma, % (n) | 9.2 (750) | 0.1 (170) |
| History of thyroid disease, % (n) | 0.9 (73) | 0.6 (680) |
| History of celiac disease, % (n) | 0.3 (25) | 0.06 (76) |
| History of Addison's disease, % (n) | 1.4 (110) | 0.3 (376) |
| Inpatient DM diagnosis, % (n) | 67.8 (5,547) | 65.8 (79,896) |
| Outpatient DM diagnosis, % (n) | 20.4 (1,669) | 11.23 (13,647) |
| ER DM diagnosis,% (n) | 41.3 (3,371) | 34.1 (41,435) |
a
SD, standard deviation; CABG, coronary artery bypass graft; MI, myocardial infarction.
b
ICD-9 code of DM: T1DM only = only with ICD-9 code for T1DM-specific diagnosis (250.×1 or 250.×3); T2DM or unspecified DM only = only with ICD-9 code for T2DM or unspecified type DM diagnosis (250.×0 or 250.×2); both T1DM and T2DM = with both ICD-9 codes for T1DM and T2DM or unspecified diagnosis [(250.×1 or 250.×3) and (250.×0 or 250.×2)]; missing values = without any ICD-9 code diagnosis for DM.
c
Complications include coronary artery bypass graft, myocardial infarction, dialysis, retinopathy, neuropathy, and amputations.