Table 2 Assessment of certainty of evidence using the GRADE evidence profile

Migraine

13

Observational studies

very serious^a

not serious

serious^b

not serious

strong association

2,859/32,489 (8.8%)

12,030/299,166 (4.0%)

OR 2.25

(1.85 to 2.72)

46 more per 1,000

(from 32 more to 62 more)

⨁⨁◯◯

Low^{a, b}

Migraine without aura

3

Observational studies

very serious^c

not serious

serious^b

not serious

strong association

137/482 (28.4%)

63/488

(12.9%)

OR 2.64

(1.89 to 3.69)

152 more per 1,000

(from 90 more to 224 more)

⨁◯◯◯

Very low^{b, c}

Migraine with aura

3

Observational studies

very serious^c

serious^d

serious^b

very serious^e

limited evidence, heterogeneity of findings

28/482

(5.8%)

8/488

(1.6%)

OR 3.47

(0.53 to 22.89)

37 more per 1,000

(from 7 fewer to 255 more)

⨁◯◯◯

Very low^{b, c,d, e}