Table 1.
Characteristics of the study cohort.
| Admissions |
|||
|---|---|---|---|
| Variables | Total (n=995,379) |
High ED Crowding (n=197,325; 20%)* |
Normal ED Crowding (n=798,054; 80%) |
| Ambulance diversion hours | |||
| Median (IQR) | 0.6 (0, 4.67) | 7.1 (3.6, 11.2) | 0 (0, 2.2) |
| Outcomes | |||
| Inpatient mortality, No. (%)† | 36,281 (3.6) | 7,628 (3.9) | 28,653 (3.6) |
| Length of stay, days | |||
| Mean (SD)† | 5 (±7) | 5 (±7) | 5 (±7) |
| Median (IQR) | 3 (2, 6) | 3 (2, 6) | 3 (2, 6) |
| Costs, $ | |||
| Mean (SD)† | 12,787 (21,134) | 13,089 (22,301) | 12,710 (20,827) |
| Median (IQR) | 7,423 (4,378, 13,548) | 7,410 (4,348, 13,678) | 7,524 (4,386, 13,515) |
| Covariates | |||
| Age (SD), mean, y† | 62.2 (19.6) | 62.1 (19.6) | 62.2 (19.6) |
| Male (%) | 472,048 (47.4) | 94,217 (47.8) | 377,831 (47.3) |
| Nonwhite (%) | 312,116 (31.4) | 62,059 (31.5) | 250,057 (31.3) |
| Selected comorbidities | |||
| Hypertension (%) | 478,431 (48.1) | 94,184 (47.7) | 384,427 (48.1) |
| Uncomplicated diabetes mellitus (%) | 177,789 (17.9) | 35,361 (17.9) | 142,428 (17.8) |
| Chronic pulmonary disease (%)‡ | 135,461 (13.6) | 26,743 (13.6) | 108,718 (13.6) |
| Renal failure (%)† | 132,336 (13.3) | 26,455 (13.4) | 105,881 (13.3) |
| Congestive heart failure (%)‡ | 103,073 (10.4) | 20,320 (10.3) | 82,753 (10.4) |
IQR, interquartile range; SD, standard deviation; y, years.
*
The percent of facility-days categorized as those with high ED crowding (17%) was less than 25% of all facility-days; thus, less than 25% of all admissions occurred on high ED crowding days.
†
For high vs normal ED crowding for outcomes and covariates, P<.001.
‡
For high vs normal ED crowding for outcomes and covariates, P<.05.