Table 1.
Sample characteristics of unmatched factors by case status
| All patients | Case subjects | Control subjects | P* | |
|---|---|---|---|---|
| n | 1,990 | 995 | 995 | |
| Insulin regimen | ||||
| Glargine | 630 (31.7) | 38.1 | 25.2 | <0.001 |
| NPH | 316 (15.9) | 22.4 | 9.3 | |
| Lispro and/or regular only† | 566 (28.4) | 19.5 | 37.4 | |
| None | 478 (24.0) | 20.0 | 28.0 | |
| Basal-to-total insulin dose ratio | ||||
| 0.00 | 566 (28.4) | 19.5 | 37.4 | <0.001 |
| 0.01–0.39 | 99 (5.0) | 4.5 | 5.4 | |
| 0.40–0.59 | 267 (13.4) | 16.3 | 10.6 | |
| 0.60–1.00 | 580 (29.1) | 39.7 | 18.6 | |
| No insulin | 478 (24.0) | 20.0 | 28.0 | |
| SSI use | ||||
| SSI only | 503 (25.3) | 16.6 | 34.0 | <0.001 |
| SSI plus scheduled insulin | 737 (37.0) | 42.9 | 31.2 | |
| No SSI | 750 (37.7) | 40.5 | 34.9 | |
| Medication use in hospital | ||||
| Metformin | 417 (54.3) | 49.9 | 58.8 | 0.086 |
| Sulfonylureas | 254 (32.8) | 35.7 | 30.3 | |
| Thiazolidinediones | 97 (12.6) | 14.4 | 10.8 | |
| Glucocorticoids | 210 (10.6) | 10.2 | 11.0 | 0.558 |
| Weight (kg) | 85.6 ± 27.0 | 85.2 ± 27.7 | 86.1 ± 26.2 | 0.301 |
| Race | ||||
| African American | 799 (40.6) | 41.8 | 39.4 | 0.167 |
| White | 671 (34.1) | 32.2 | 36.0 | |
| Hispanic | 274 (13.90 | 15.1 | 12.7 | |
| Other | 225 (11.4) | 11.0 | 11.9 | |
| Laboratory studies | ||||
| A1C (%) | 8.1 ± 2.2 | 8.0 ± 2.1 | 8.1 ± 2.3 | 0.438 |
| Albumin (g/dL) | 3.5 ± 0.6 | 3.4 ± 0.6 | 3.5 ± 0.5 | <0.001 |
| Alanine aminotransferase (units/L) | 34.6 ± 99.3 | 34.6 ± 101.2 | 34.5 ± 97.4 | 0.867 |
| Aspartate aminotransferase (units/L) | 41.3 ± 219.9 | 40.1 ± 172.9 | 42.6 ± 260.7 | 0.937 |
| Creatinine (mg/dL) | 1.5 ± 1.7 | 1.7 ± 2.0 | 1.3 ± 1.2 | <0.001 |
| Hematocrit (%) | 32.8 ± 5.2 | 32.1 ± 5.0 | 33.6 ± 5.3 | <0.001 |
| WBC (k/UL) | 8.4 ± 4.1 | 8.4 ± 4.4 | 8.5 ± 3.7 | 0.553 |
| Fasting within prior 24 h‡ | 403 (20.3) | 50.6 | 49.4 | 0.774 |
| Primary service‡ | ||||
| Medicine | 1,404 | 73.5 | 68.1 | 0.008 |
| Surgery | 580 | 26.5 | 31.9 | |
| Comorbidity index | ||||
| 0 | 107 (5.40) | 4.6 | 6.1 | <0.001 |
| 1–2 | 803 (40.4) | 36.4 | 44.3 | |
| 3–4 | 682 (34.3) | 36.4 | 32.2 | |
| 5–6 | 282 (14.2) | 17.3 | 11.1 | |
| >6 | 116 (5.8) | 5.3 | 6.3 | |
| Length of stay (days) | 7.6 ± 7.0 | 8.1 ± 8.2 | 7.1 ± 5.5 | <0.001 |
Data are n (%), percentages, or means ± SD.
*P values for categorical variables were generated by χ2 tests. P values for continuous variables were generated by t tests.
†Hypoglycemia prevalence among patients who received lispro was similar to that among patients given regular insulin (31.8 vs. 36.1%).
‡Excludes six patients with missing values.