| ICU | intensive care unit |
| IC | confidence interval |
| OR | Odds Ratio |
| PTH | parathyroid hormone |
| COPD | Chronic Obstructive Pulmonary Disease |
| HCW | healthcare worker |
| RCT | randomized control trial |
| ICU | intensive care unit |
| IC | confidence interval |
| OR | Odds Ratio |
| PTH | parathyroid hormone |
| COPD | Chronic Obstructive Pulmonary Disease |
| HCW | healthcare worker |
| RCT | randomized control trial |