Table 1 Characteristics of study population
| Â | Hospital volume | Â | ||
|---|---|---|---|---|
Low (n = 149,182) | Medium (n = 149,507) | High (n = 149,129) | p value | |
Number of hospital | 648 | 190 | 107 | Â |
Number of patients in each hospital | 400 (276–504) | 810 (692–919) | 1405 (1158–1634) |  |
Age (years) | 81 (72–87) | 81 (72–87) | 80 (71–86) | < 0.001 |
Age ≥ 85 years | 53,068 (35.6) | 51,603 (34.5) | 48,549 (32.6) | < 0.001 |
Male sex | 78,205 (52.4) | 79,548 (53.2) | 80,439 (53.9) | < 0.001 |
Body mass index (kg/m2) | 22.1 (19.6–25.0) | 22.2 (19.6–25.0) | 22.0 (19.5–24.8) | < 0.001 |
Hypertension | 96,539 (64.7) | 102,989 (68.9) | 101,547 (68.1) | < 0.001 |
Diabetes mellitus | 45,518 (30.5) | 48,361 (32.3) | 47,140 (31.6) | < 0.001 |
Chronic renal failure | 20,996 (14.1) | 22,222 (14.9) | 22,285 (14.9) | < 0.001 |
Chronic liver disease | 6086 (4.1) | 6185 (4.1) | 5246 (3.5) | < 0.001 |
Chronic respiratory disease | 17,282 (11.6) | 17,707 (11.8) | 15,752 (10.6) | < 0.001 |
Smoking | 43,317 (29.0) | 48,219 (32.3) | 52,262 (35.0) | < 0.001 |
Myocardial infarction | 3,699 (2.5) | 4,182 (2.8) | 4,636 (3.1) | < 0.001 |
Dilated cardiomyopathy | 10,853 (7.3) | 11,463 (7.7) | 11,810 (7.9) | < 0.001 |
Ventricular tachycardia/ventricular fibrillation | 5,751 (3.9) | 6,664 (4.5) | 7,874 (5.3) | < 0.001 |
Shock | 2,918 (2.0) | 3,167 (2.1) | 2,680 (1.8) | < 0.001 |
Anemia | 21,466 (14.4) | 24,775 (16.6) | 25,373 (17.0) | < 0.001 |
Barthel Index | 65 (15–100) | 65 (15–100) | 55 (5–100) | < 0.001 |
New York Heart Association |  |  |  | < 0.001 |
Class II | 46,002 (30.8) | 43,519 (29.1) | 40,294 (27.0) | Â |
Class III | 58,106 (38.9) | 57,366 (38.4) | 55,967 (37.5) | Â |
Class IV | 45,074 (30.2) | 48,622 (32.5) | 52,868 (35.5) | Â |
Medications within two days after admission | Â | Â | Â | Â |
Beta blocker | 44,322 (29.7) | 48,517 (32.5) | 55,547 (37.2) | < 0.001 |
Renin-angiotensin system inhibitor | 50,814 (34.1) | 53,377 (35.7) | 62,167 (41.7) | < 0.001 |
Angiotensin converting enzyme inhibitor | 21,565 (14.5) | 23,160 (15.5) | 26,987 (18.1) | < 0.001 |
Angiotensin II receptor blocker | 30,206 (20.2) | 31,180 (20.9) | 36,480 (24.5) | < 0.001 |
Mineralocorticoid receptor antagonist | 44,609 (29.9) | 47,290 (31.6) | 53,716 (36.0) | < 0.001 |
Intravenous inotropic agent | 24,788 (16.6) | 25,138 (16.8) | 28,310 (19.0) | < 0.001 |
Intravenous nitrate | 26,825 (18.0) | 31,741 (21.2) | 34,999 (23.5) | < 0.001 |
Intravenous furosemide | 97,917 (65.6) | 101,240 (67.7) | 105,515 (70.8) | < 0.001 |