. Author manuscript; available in PMC: 2022 Feb 1.

Published in final edited form as: Headache. 2020 Nov 25;61(2):343–350. doi: 10.1111/head.14016

Table 2:

Univariate linear regression models examining variables associated with headache frequency

	Difference between groups in headache days/month (95% confidence interval)
High School Start time before 8:30 AM	2.9 (2.2 to 3.6)
Being on a migraine preventive medication	2.6 (1.9 to 3.3)
Female sex (as determined at birth)	1.4 (0.7 to 2.1)
Getting at least 8 hours of sleep on weeknights	−1.9 (−2.6 to −1.2)
Hours of sleep on a school night (per hour)	−1.2 (−1.4 to −0.9)
Hours of sleep on a weekend night (per hour)	−0.3 (−0.5 to −0.1)
Age (per year)	−0.2 (−0.5 to 0.1)
Days of acute medication use (per day of use)	0.9 (0.8 to 1.0)
Hours of homework on a school night (per hour of homework)	0.7 (0.4 to 1.0)
Days of missed breakfast per 5-day school week (per day of missed breakfast)	1.0 (0.8 to 1.1)
Sleep midpoint variability (per 100 minutes)	0.7 (0.1 to 1.3)
Grade:
9th	Reference
10^th	0.8 (−0.4 to 2.0)
11^th	−0.9 (−2.0 to 0.2)
12^th	0.8 (−0.4 to 2.0)