Table 1.

Effect of voice and mask use on COVID‐19 severity

Variable	Mean	SD	5%	95%
Intercept	2.0	0.34	1.5	2.6
Total voice use	0.035	0.063	−0.069	0.14
Total mask use	−0.077	0.11	−0.27	0.12
Voice × mask	−0.072	0.042	−0.14	−0.003

Shown are the mean, standard deviation, and credible interval (5–95%) of the posterior probability for the given parameter for a linear model, where severity is given by the sum of the first three principal components of the list of symptoms. The ordinal regression model used is Severity ∼g(Voice + Mask + Mask × Voice + comorbidities + demographics + baseline risk), where g is the link function (logit and probit gave similar results), and mask use was converted to a continuous quantity. Comorbidities included the history of issues with the cardiovascular system, immune system, high blood pressure and diabetes. Demographic information includes sex, age, race, BMI, health information and occupational status.