Characteristics of included hospitalisations
| (n=36 966) | |
| Age in years (mean +/− SD) | 61.7 (17.4) |
| ≥65 years old (%) | 17 237 (46.9) |
| Female, n (%) | 20 064 (54.3) |
| Ethnicity, n (%) | |
| White | 23 042 (62.3) |
| Black | 7241 (19.6) |
| Hispanic | 5499 (14.9) |
| Other | 1184 (3.2) |
| Hospital type, n (%) | |
| County | 9328 (25.2) |
| Non-county | 27 638 (74.8) |
| Length of stay, median (IQR) | 4 (2–6) |
| Charlson comorbidity index*, n (%) | |
| 0 | 22 233 (60.1) |
| 1 | 2682 (7.3) |
| 2+ | 12 051 (32.6) |
| Cardiopulmonary primary discharge diagnosis†, n (%) | 5814 (15.7) |
| Sepsis | 656 (1.8) |
| Pneumonia | 1431 (3.9) |
| COPD exacerbation | 787 (2.1) |
| CHF exacerbation | 2003 (5.4) |
| Asthma exacerbation | 423 (1.1) |
| Myocardial infarction | 514 (1.4) |
| Oxygen saturation, minimum value on admission, n (%) | |
| ≥92% | 30 481 (82.5) |
| <92% | 5860 (15.8) |
| Missing oxygen saturation | 625 (1.7) |
*Charlson comorbidity index was calculated using the Deyo modification.
†Classified using the AHRQ Clinical Classifications Software.
CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease.