Table 1. Characteristics of participants and post-vaccine menstruation.

IQR: interquartile range

Predictors	Affected (n=146)	Unaffected (n=238)	p-Value	Odds ratio (OR)	95% confidence interval
	Median (IQR) or n (%)	Median (IQR) or n (%)
Age	21 (3.0)	21 (2.0)	0.981	0.999	0.946-1.055
Body mass index	21.5 (6.2)	20.7 (5.3)	0.348	1.023	0.976-1.071
PSS score	24 (9.0)	21 (8.0)	0.017	1.041	1.007-1.076
Marital status
Unmarried	131 (89.7%)	215 (90.3%)	-	-	-
Married	15 (10.3%)	23 (9.7%)	0.743	0.844	0.306-2.329
Physical activity
None	5 (3.4%)	15 (6.3%)	0.093	-	-
Light	57 (39.0%)	95 (40.0%)	0.383	1.621	0.547-4.806
Moderate	71 (48.7%)	121 (50.8%)	0.256	1.847	0.628-5.431
Strenuous	13 (8.9%)	7 (2.9%)	0.020	5.626	1.320-23.981
Pre-vaccination cycle regularity
No	21 (14.4%)	27 (11.3%)	-	-	-
Yes	125 (85.6%)	211 (88.7%)	0.543	0.816	0.424-1.571
Pre-vaccination menstrual flow
Scanty	10 (6.9%)	2 (0.8%)	0.002	-	-
Normal	111 (76.0%)	218 (91.6%)	0.007	0.118	0.025-0.562
Heavy	25 (17.1%)	18 (7.6%)	0.129	0.275	0.052-1.454