Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Groups of operations in the pre-pandemic and pandemic periods
| Groups | Pre-pandemic year (2019) | Pandemic year (2020) | Z-Statistics | p-value |
|---|---|---|---|---|
| A, n (%) | 90 (10.3) | 30 (25.9) | −4.669 | < 0.001 |
| B, n (%) | 47 (5.4) | 20 (17.2) | −4.578 | < 0.001 |
| C, n (%) | 436 (49.9) | 36 (31.0) | 3.732 | < 0.001 |
| D, n (%) | 267 (30.6) | 20 (17.2) | 2.866 | 0.004 |
| E, n (%) | 33 (3.8) | 10 (8.6) | −2.160 | 0.031 |
| Total | 873 (100) | 116 (100) |
