. Author manuscript; available in PMC: 2021 Oct 25.

Published in final edited form as: Cephalalgia. 2017 Aug 20;38(6):1188–1198. doi: 10.1177/0333102417727535

Table 2.

Individual trigger meta-analyses.

Trigger category	Proportion	95% CI	I²	Studies	Total N
Stress	.58	.53, .63	97	57	18219
Sleep	.41	.36, .47	97	53	17778
Emotion	.33	.26, .41	96	26	6110
Weather/environment	.32	.27, .39	98	53	18349
Visual	.32	.25, .39	98	47	14539
Hormones	.29	.25, .35	97	38	13592
Food/eating habits	.27	.22, .32	97	53	17142
Smell/odor	.22	.17, .27	98	41	14633
Alcohol	.21	.16, .26	98	43	12400
Activity/exertion	.20	.15, .27	98	46	13691
Other	.20	.14, .26	97	25	8219
Auditory	.16	.08, .31	98	19	5143
Travel	.11	.06, .19	98	17	5316
Allergy/sinus	.06	.02, .13	92	7	1842
Medications	.02	.01, .08	92	5	2010