Table 1.

Methods of defining peak-ranges of confirmed COVID-19 cases.

Method	Method description	Early warning level / Cutoff level	Peak range
Method I	Data sequence numerical increase or decrease	Continual increase for ≥14 consecutive data points. Peak range begins at day 0. Peaks at the maximum, and ends symmetrically	10/6/20–12/24/20, 2/27/21–5/1/21, 7/17/21–10/2/21, 10/29/21–1/22/22, 3/31/22–5/31/22
Method II	Variance / mean	Intersection values > variance/mean threshold	11/4/20-12/13/20, 3/19/21-5/4/21, 10/18/21-10/25/21, 11/5/21-2/7/22, 5/4/22-5/24/22
Method III	Mean – 0.5standard deviation (SD)	Intersection values > mean-0.5SD threshold	9/25/20-9/27/20, 10/24/20-1/20/21, 2/8/21-2/21/21, 3/12/21-5/10/21, 5/15/21-5/31/21, 7/29/21-9/6/21, 9/14/21-2/17/22, 4/18/22-5/31/22