Table 1.
Baseline Patient and Hospital Characteristics*
| Characteristic | Total (n=11880) | ICD (n=4739) | No ICD (n=7141) | P Value |
|---|---|---|---|---|
| Patient | ||||
|
| ||||
| Age, median (25th, 75th), y | 77 (71, 83) | 75 (70, 80) | 79 (72, 84) | <0.0001 |
| Male | 63.9 | 73.5 | 57.6 | <0.0001 |
| Race | <0.0001 | |||
| Black | 13.6 | 12.3 | 14.5 | |
| White | 77.4 | 79.5 | 76.0 | |
| Systolic blood pressure, median (25th, 75th), mm Hg | 131 (114, 150) | 126 (110, 144) | 134 (117, 154) | <0.0001 |
| Diastolic blood pressure, median (25th, 75th), mm Hg | 73 (63, 84) | 70 (62, 81) | 75 (65, 87) | <0.0001 |
| Heart rate, median (25th, 75th), bpm | 80 (70, 94) | 76 (68, 88) | 84 (72, 98) | <0.0001 |
| Body mass index, median (25th, 75th) | 26.4 (23.1, 30.5) | 26.7 (23.6, 30.7) | 26.0 (22.7, 30.1) | 0.0018 |
| History | ||||
| Anemia | 13.8 | 12.3 | 15.0 | <0.0001 |
| Atrial fibrillation | 33.8 | 36.5 | 31.9 | 0.0096 |
| Cerebrovascular disease or transient ischemic attack | 13.5 | 12.9 | 13.9 | 0.0050 |
| Depression | 6.7 | 6.6 | 6.8 | 0.50 |
| Diabetes mellitus | 39.4 | 39.4 | 39.3 | 0.86 |
| Hyperlipidemia | 46.9 | 53.4 | 42.1 | <0.0001 |
| Hypertension | 70.1 | 68.4 | 71.5 | <0.0001 |
| Ischemic heart disease | 69.8 | 75.5 | 65.5 | <0.0001 |
| Peripheral vascular disease | 13.6 | 14.0 | 13.4 | 0.61 |
| Pulmonary disease | 26.4 | 25.8 | 26.9 | 0.12 |
| Renal insufficiency (creatinine >2.0 mg/dL) | 19.3 | 20.4 | 18.4 | 0.23 |
| Smoking | 12.0 | 11.8 | 12.1 | 0.86 |
| Left ventricular ejection fraction, median (25th, 75th), % | 25 (20, 30) | 25 (20, 30) | 25 (20, 30) | <0.0001 |
|
| ||||
| Hospital | ||||
|
| ||||
| Number of beds, median (25th, 75th) | 382 (243, 581) | 470 (324, 676) | 330 (217, 571) | <0.0001 |
| Region | <0.0001 | |||
| Northeast | 29.5 | 30.0 | 29.4 | |
| Midwest | 25.8 | 30.0 | 23.2 | |
| South | 34.6 | 31.5 | 36.7 | |
| West | 9.6 | 8.5 | 10.3 | |
| Academic site | 55.1 | 61.6 | 50.8 | <0.0001 |
Abbreviations: bpm, beats per minute; ICD, implantable cardioverter-defibrillator.
*
Data are presented as percentages unless otherwise indicated. Data are based on patients with available data for each characteristic.
P-values were calculated by comparing only non-missing row values. P-values are based on stratum adjusted Pearson chi-square tests for all categorical row variables.
P-values are based on stratum adjusted chi-square rank based group means score statistics for all continuous/ordinal row variables. This is equivalent to stratum adjusted Wilcoxon tests.
All tests treat the column variable as nominal.
All tests are adjusted for confounding by hospitals except for hospital characteristics.