The Efficacy of Percutaneous Patent Foramen Ovale Closure on Migraine: a Meta-Analysis of Randomized Controlled Trials and Observational Studies

Table 2

NOS score of included cohort studies.

Score category	Score	Biasco	Rigatelli
Selection
Representativeness of the exposed cohort	1	1	1
Selection of the nonexposed cohort	1	1	1
Ascertainment of exposure	1	1	1
Demonstration that outcome of interest was not present at start of study	1	1	1
Comparability
Comparability of cohorts on the basis of the design or analysis	2	1	1
Outcome
Assessment of outcome	1	1	1
Was followed up long enough for outcomes to occur	1	1	1
Adequacy of follow-up of cohorts	1	1	1
Total score		8	8

Note: A study can be awarded a maximum of one star for each numbered item within the Selection and Exposure categories/Selection and Outcome categories. A maximum of two stars can be given for Comparability.