Table 1. Baseline Characteristics of Patients During the Pandemic Period of March 16 Through April 30, 2020, vs the Same Period in 2019.
| Variable | Patients, No. (%) | Standardized difference, %a | |
|---|---|---|---|
| 2019 (n = 9440) | 2020 (n = 9863) | ||
| Patient factors | |||
| Age, y | |||
| Mean (SD) | 62.2 (19.2) | 62.6 (19.3) | 2.1 |
| Median (IQR) | 65.0 (52.0-76.0) | 65.0 (52.0-77.0) | |
| Sex | |||
| Female | 3517 (37.3) | 3819 (38.7) | 3.0 |
| Male | 5922 (62.7) | 6040 (61.3) | |
| Missing, No. | 1 | 4 | |
| Race/ethnicity | |||
| White | 4844 (51.3) | 4716 (48.1) | 17.6 |
| Black | 2137 (22.6) | 2751 (28.0) | |
| Other | 915 (9.7) | 1160 (11.8) | |
| Unknown | 1544 (16.4) | 1186 (12.1) | |
| Missing, No. | NA | 50 | |
| Cardiac arrest factors | |||
| First documented cardiac arrest rhythm | |||
| Nonshockable | |||
| Asystole | 5071 (53.7) | 5862 (59.6) | 14.2 |
| Pulseless electrical activity | 1766 (18.7) | 1801 (18.3) | |
| Unknown nonshockable rhythm | 829 (8.8) | 750 (7.6) | |
| Shockable | |||
| Ventricular fibrillation | 1277 (13.5) | 1034 (10.5) | |
| Ventricular tachycardia | 75 (0.8) | 80 (0.8) | |
| Unknown shockable rhythm | 422 (4.5) | 309 (3.1) | |
| Missing, No. | NA | 27 | |
| Location of cardiac arrest | |||
| Home | 6590 (69.8) | 7385 (74.9) | 21.3 |
| Industrial or commercial building | 771 (8.2) | 377 (3.8) | |
| Nursing home and other health care residence | 1479 (15.7) | 1609 (16.3) | |
| Street and other public areas | 455 (4.8) | 393 (4.0) | |
| Recreational facility | 104 (1.1) | 35 (0.4) | |
| Other | 41 (0.4) | 60 (0.6) | |
| Missing, No. | NA | 4 | |
| Witnessed status of cardiac arrest | |||
| Bystander witnessed | 4127 (43.7) | 4049 (41.1) | 5.4 |
| Unwitnessed | 5313 (56.3) | 5812 (58.9) | |
| Missing, No. | NA | 2 | |
| Cardiac arrest causative mechanism | |||
| Presumed cardiac | 7957 (84.3) | 7935 (80.5) | 18.5 |
| Respiratory | 769 (8.1) | 878 (8.9) | |
| Drug overdose | 582 (6.2) | 614 (6.2) | |
| Other | 132 (1.4) | 436 (4.4) | |
| Bystander cardiopulmonary resuscitation | |||
| Yes | 4418 (46.8) | 4690 (47.7) | 1.7 |
| Missing, No. | 1 | 24 | |
| Bystander defibrillation with automated external defibrillator | |||
| Yes | 766 (8.1) | 565 (5.7) | 9.4 |
| Missing, No. | NA | 1 | |
| EMS treatment time intervals, median (IQR)b | |||
| Time from 911 call to EMS arrival | 8.5 (6.5-11.3) | 9.0 (6.9-12.0) | 0.5 |
| Duration of EMS treatment | 22.2 (15.0-32.0) | 24.8 (16.7-37.0) | 3.4 |
Abbreviations: EMS, emergency medical services; IQR, interquartile range; NA, not applicable.
a
Given the large sample size, P values are not reported. Instead, standardized differences of more than 10% are used to denote a meaningful difference between 2020 vs 2019.
b
Data were missing in 23% of patients for the interval from 911 call to EMS arrival and 50% of patients for duration of EMS treatment.