Figure 3.

Circadian phase uncertainty increased around COVID symptom onset

(A) The HR algorithm samples the circadian phase from the posterior distribution a user-specified amount of times. The blue bars plot the histogram of circadian phase samples from 1 day of data in one example individual. The red line (5:54 a.m.) is the mean circadian phase from the sampled distribution and is taken as the estimate of the circadian phase for the day. The dashed red lines are the uncertainty bounds that correspond to the number of hours on either side of the phase estimate containing 80% of the samples (in this case, 5.61 h).

(B) Sample actogram for one participant from days −50 to 5 around COVID symptom onset. The black histogram-like bars represent HR throughout the day, i.e., thicker bars correspond to higher HR values in the 5-min bin. The actogram is double plotted; that is, the first row plots HR on day −50 and then day −49, the second row days −49 and −48, etc. The red line plots the circadian phase estimate from the HR algorithm with the shaded region representing the hours of uncertainty in that estimate. See STAR Methods and (A).

(C) The mean phase uncertainty in hours for days −35 to 14 around COVID symptom onset in the whole population. The shaded region corresponds to the SE of the mean. The uncertainty was increased when compared with our previously published algorithm because of the shorter window of data.