Table 4.
Characteristics of Hospitalized Patients With Diabetes in Internal and External Validation Samples
| Variable | All discharges N = 123,761 | Internal validation n = 17,801 | External validation n = 105,960 | P value |
|---|---|---|---|---|
| Age | <.0001 | |||
| <50 years | 10,160 (8.2) | 3,303 (18.6) | 6,857 (6.5) | |
| 50–59 years | 17,190 (13.9) | 4,219 (23.7) | 12,971 (12.2) | |
| 60–69 years | 30,510 (24.7) | 4,521 (25.4) | 25,989 (24.5) | |
| 70+ years | 65,901 (53.3) | 5,758 (32.4) | 60,143 (56.8) | |
| Gender | <.0001 | |||
| Female | 56,951 (46.0) | 9,011 (50.6) | 47,940 (45.2) | |
| Male | 66,810 (54.0) | 8,790 (49.4) | 58,020 (54.8) | |
| Weight (kg), mean (SD) | 85.9 (20.41) | 85.0 (20.78) | 86.1 (20.32) | .0026 |
| Marital status | <.0001 | |||
| Married | 54,881 (44.3) | 5,716 (32.1) | 49,165 (46.4) | |
| Single | 64,458 (52.1) | 11,742 (66.0) | 52,716 (49.8) | |
| Other or not recorded | 4,422 (3.6) | 343 (1.9) | 4,079 (3.9) | |
| Race/ethnicity | <.0001 | |||
| Black | 19,269 (15.6) | 7,939 (44.6) | 11,330 (10.7) | |
| Hispanic | 8,572 (6.9) | 2,658 (14.9) | 5,914 (5.6) | |
| White | 84,032 (67.9) | 6,032 (33.9) | 78,000 (73.6) | |
| Other | 6,932 (5.6) | 981 (5.5) | 5,951 (5.6) | |
| Not recorded | 4,956 (4.0) | 191 (1.1) | 4,765 (4.5) | |
| English speaking | <.0001 | |||
| Yes | 107,258 (86.7) | 14,371 (80.7) | 92,887 (87.7) | |
| No | 16,503 (13.3) | 3,430 (19.3) | 13,073 (12.3) | |
| Insurance status | <.0001 | |||
| Medicaid | 5,914 (4.8) | 4,080 (22.9) | 1,834 (1.7) | |
| Medicare | 61,731 (49.9) | 8,818 (49.5) | 52,913 (49.9) | |
| None | 13,033 (10.5) | 883 (5.0) | 12,150 (11.5) | |
| Private | 43,083 (34.8) | 4,020 (22.6) | 39,063 (36.9) | |
| Home zip coded | <.0001 | |||
| ≥5 miles from hospital | 78,942 (63.8) | 5,570 (31.3) | 73,372 (69.2) | |
| <5 miles from hospital | 44,819 (36.2) | 12,231 (68.7) | 32,588 (30.8) | |
| Educational level | <.0001 | |||
| Less than high school | 15,115 (12.2) | 2,540 (14.3) | 12,575 (11.9) | |
| Any high school | 37,618 (30.4) | 9,571 (53.8) | 28,047 (26.5) | |
| Some college | 5,472 (4.4) | 1,148 (6.5) | 4,324 (4.1) | |
| College graduate | 21,960 (17.7) | 2,804 (15.8) | 19,156 (18.1) | |
| Not recorded | 43,596 (35.2) | 1,738 (9.8) | 41,858 (39.5) | |
| Employmentd | <.0001 | |||
| Disabled | 18,129 (14.7) | 3,683 (20.7) | 14,446 (13.6) | |
| Employed | 19,964 (16.1) | 1,746 (9.8) | 18,218 (17.2) | |
| Retired | 47,047 (38.0) | 6,990 (39.3) | 40,057 (37.8) | |
| Unemployed | 11,574 (9.4) | 4,819 (27.1) | 6,755 (6.4) | |
| Other or not recorded | 27,047 (21.9) | 563 (3.2) | 26,484 (25.0) | |
| Pre-admission sulfonylurea use | .039 | |||
| Yes | 18,580 (15.0) | 2,858 (16.1) | 15,722 (14.8) | |
| No | 105,181 (85.0) | 14,943 (83.9) | 90,238 (85.2) | |
| Pre-admission metformin use | <.0001 | |||
| Yes | 26,368 (21.3) | 5,013 (28.2) | 21,355 (20.2) | |
| No | 97,393 (78.7) | 12,788 (71.8) | 84,605 (79.9) | |
| Pre-admission thiazolidinedione use | <.0001 | |||
| Yes | 4,091 (3.3) | 1,243 (7.0) | 2,848 (2.7) | |
| No | 119,670 (96.7) | 16,558 (93.0) | 103,112 (97.3) | |
| Pre-admission insulin used | .30 | |||
| Yes | 44,382 (35.9) | 6,531 (36.7) | 37,851 (35.7) | |
| No | 79,379 (64.1) | 11,270 (63.3) | 68,109 (64.3) | |
| Pre-admission glucocorticoid use | .0034 | |||
| Yes | 13,472 (10.9) | 1,679 (9.4) | 11,793 (11.1) | |
| No | 110,289 (89.1) | 16,122 (90.6) | 94,167 (88.9) | |
| Current or prior DKA or HHS | <.0001 | |||
| Yes | 5,478 (4.4) | 1,231 (6.9) | 4,247 (4.0) | |
| No | 118,283 (95.6) | 16,570 (93.1) | 101,713 (96.0) | |
| Microvascular complicationsa | .19 | |||
| 0 | 86,979 (70.3) | 12,366 (69.5) | 74,613 (70.4) | |
| 1 | 21,853 (17.7) | 3,354 (18.8) | 18,499 (17.5) | |
| 2 | 9,329 (7.5) | 1,377 (7.7) | 7,952 (7.5) | |
| 3 | 5,600 (4.5) | 704 (4.0) | 4,896 (4.6) | |
| Macrovascular complicationsb,d | <.0001 | |||
| 0 | 44,973 (36.3) | 7,740 (43.5) | 37,233 (35.1) | |
| 1 | 36,540 (29.5) | 5,228 (29.4) | 31,312 (29.6) | |
| 2 | 29,242 (23.6) | 3,559 (20.0) | 25,683 (24.2) | |
| 3 | 10,337 (8.4) | 1,052 (5.9) | 9,285 (8.8) | |
| 4 | 2,669 (2.2) | 222 (1.3) | 2,447 (2.3) | |
| Pre-admission BP meds | <.0001 | |||
| None | 50,789 (41.0) | 4,949 (27.8) | 45,840 (43.3) | |
| ACE-i or ARB | 46,966 (38.0) | 8,595 (48.3) | 38,371 (36.2) | |
| Non-ACE or ARB | 26,006 (21.0) | 4,257 (23.9) | 21,749 (20.5) | |
| Pre-admission statin use | <.0001 | |||
| Yes | 53,754 (43.4) | 8,571 (48.2) | 45,183 (42.6) | |
| No | 70,007 (56.6) | 9,230 (51.9) | 60,777 (57.4) | |
| White blood cell count | <.0001 | |||
| Low <4 K/μL | 4,934 (4.0) | 793 (4.5) | 4,141 (3.9) | |
| Normal 4–11 K/μL | 81,937 (66.2) | 13,700 (77.0) | 68,237 (64.4) | |
| High >11 K/μL | 36,890 (29.8) | 3,308 (18.6) | 33,582 (31.7) | |
| Hematocritd, %, mean (SD) | 35.2 (5.63) | 33.7 (5.34) | 35.5 (5.63) | <.0001 |
| Serum sodiumd | <.0001 | |||
| Low <135 mmol/L | 29,061 (23.5) | 2,013 (11.3) | 27,048 (25.5) | |
| Normal 135–145 mmol/L | 93,298 (75.4) | 15,595 (87.6) | 77,703 (73.3) | |
| High >145 mmol/L | 1,402 (1.1) | 193 (1.1) | 1,209 (1.1) | |
| Serum potassium | .0003 | |||
| Low <3.1 mmol/L | 2,104 (1.7) | 238 (1.3) | 1,866 (1.8) | |
| Normal 3.1–5.3 mmol/L | 112,376 (90.8) | 16,302 (91.6) | 96,074 (90.7) | |
| High >5.3 mmol/L | 9,281 (7.5) | 1,261 (7.1) | 8,020 (7.6) | |
| Creatinined, mg/dL, median (IQR) | 1.1 (0.9–1.7) | 1.0 (0.7–1.4) | 1.2 (0.9–1.7) | .027 |
| Discharged 90 days prior to index admissiond | .12 | |||
| Yes | 38,112 (30.8) | 5,661 (31.8) | 32,451 (30.6) | |
| No | 85,649 (69.2) | 12,140 (68.2) | 73,509 (69.4) | |
| Length-of-stay, days, median (IQR) | 5.0 (3.0–8.0) | 3.7 (2.1–6.2) | 5.0 (3.0–8.0) | <.0001 |
| Discharge status of index admission | <.0001 | |||
| Home | 31,796 (25.7) | 10,372 (58.3) | 21,424 (20.2) | |
| Home with nursing care | 42,237 (34.1) | 3,448 (19.4) | 38,789 (36.6) | |
| Subacute facility | 25,307 (20.5) | 3,454 (19.4) | 21,853 (20.6) | |
| Against medical advice | 1,195 (1.0) | 392 (2.2) | 803 (0.8) | |
| Other | 1,352 (1.1) | 133 (0.8) | 1,219 (1.2) | |
| No status recorded | 21,874 (17.7) | 2 (0.01) | 21,872 (20.6) | |
| Discharge 1 year prior to index admissiond | <.0001 | |||
| Home | 17,198 (13.9) | 6,419 (36.1) | 10,779 (10.2) | |
| Home with nursing care | 20,781 (16.8) | 2,362 (13.3) | 18,419 (17.4) | |
| Sub-acute facility | 12,098 (9.8) | 2,082 (11.7) | 10,016 (9.5) | |
| Against medical advice | 723 (0.6) | 282 (1.6) | 441 (0.4) | |
| No discharge recorded | 72,961 (59.0) | 6,656 (37.4) | 66,305 (62.6) | |
| Body mass index | <.0001 | |||
| <18.5 kg/m2 | 2,017 (1.6) | 422 (2.4) | 1,595 (1.5) | |
| 18.5–24.9 kg/m2 | 20,147 (16.3) | 3,007 (16.9) | 17,140 (16.2) | |
| 25.0–29.9 kg/m2 | 37,644 (30.4) | 4,925 (27.7) | 32,719 (30.9) | |
| ≥30.0 kg/m2 | 63,953 (51.7) | 9,447 (53.1) | 54,506 (51.4) | |
| Depression or psychosis ever | <.0001 | |||
| Yes | 27,748 (22.4) | 5,242 (29.5) | 22,506 (21.2) | |
| No | 96,013 (77.6) | 12,559 (70.6) | 83,454 (78.8) | |
| Gastroparesis ever | .0042 | |||
| Yes | 4,319 (3.5) | 904 (5.1) | 3,415 (3.2) | |
| No | 119,442 (96.5) | 16,897 (94.9) | 102,545 (96.8) | |
| Pancreatitis ever | ||||
| Yes | 5,456 (4.4) | 974 (5.5) | 4,482 (4.2) | .021 |
| No | 118,305 (95.6) | 16,827 (94.5) | 101,478 (95.8) | |
| Hypertension ever | <.0001 | |||
| Yes | 87,421 (70.6) | 13,242 (74.4) | 74,179 (70.0) | |
| No | 36,340 (29.4) | 4,559 (25.6) | 31,781 (30.0) | |
| COPDc or asthma ever | <.0001 | |||
| Yes | 20,393 (16.5) | 4,068 (22.9) | 16,325 (15.4) | |
| No | 103,368 (83.5) | 13,733 (77.2) | 89,635 (84.6) | |
| Cardiac dysrhythmias ever | <.0001 | |||
| Yes | 39,828 (32.2) | 4,164 (23.4) | 35,664 (33.7) | |
| No | 83,933 (67.8) | 13,637 (76.6) | 70,296 (66.3) | |
| Malignant neoplasm ever | <.0001 | |||
| Yes | 20,459 (16.5) | 1,718 (9.7) | 18,741 (17.7) | |
| No | 103,302 (83.5) | 16,083 (90.4) | 87,219 (82.3) | |
| Anemia everd | .062 | |||
| Yes | 49,216 (39.8) | 7,348 (41.3) | 41,868 (39.5) | |
| No | 74,545 (60.2) | 10,453 (58.7) | 64,092 (60.5) | |
Abbreviations: ACE = angiotensin-converting enzyme; ACE-i = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; BP = blood pressure; COPD = chronic obstructive pulmonary disease; DKA = diabetic ketoacidosis; HHS = hyperglycemic hyperosmolar syndrome; IQR = interquartile range.
Data are n, (%) unless otherwise noted.
a
Retinopathy, neuropathy, nephropathy.
b
Coronary artery disease, heart failure, stroke, peripheral vascular disease.
c
COPD, chronic obstructive pulmonary disease; Ever=current or prior.
d
Included in the Diabetes Early Re-admission Risk Indicator.