Table 4

Associations between the sensitivity of the rapid antigen test compared with the PCR test and the duration from the onset of symptoms to testing during the Omicron variant outbreak among players and staff members of the Japan Professional Football League and clubs: a stratified analysis

Participants	Duration from the onset of symptoms to testing	Rapid antigen: + PCR: +	Rapid antigen: − PCR: +	Sensitivity	Cramer’s V	P value
Vaccine: yes (n=70)	−2 days or −1 day*	7	3	0.70	0.084	0.955†
	0 day	15	11	0.58
	1 day or 2 days	7	4	0.64
	Asymptomatic	14	9	0.61
Kit manufacturer: Abbott (n=45)	−2 days or −1 day*	4	3	0.57	0.181	0.688†
	0 day	13	3	0.81
	1 day or 2 days	3	1	0.75
	Asymptomatic	13	5	0.72
Sample type of PCR: saliva (n=80)	−2 days or −1 day*	6	4	0.60	0.087	0.895‡
	0 day	16	14	0.53
	1 day or 2 days	10	8	0.56
	Asymptomatic	14	8	0.64

*‘−2 days or −1 day’ represents cases that were asymptomatic at the time of the tests but subsequently developed symptoms.
†Fisher’s exact test.
‡χ² test.