Table 6. Lasso models for predicting death in swab-positive patients. Lymphocyte does not contribute to the predictive model for swab-positive patients.

COPD: Chronic obstructive pulmonary disease; Frailty: Dalhousie frailty (Rockwood) score of 4 or more classified as frail; IHD: Ischemic heart disease; ILD: Interstitial lung disease; ROC: The area under a receiver operating characteristic curve. 

Variable	Model coefficients
Age	0.012
IHD	2.943
Asthma/COPD/ILD	3.066
Frailty	2.086
ROC area (95% CI)	0.981 (0.962-1.00)