Table 3.

Newcastle–Ottawa Scale

Quality assessment criteria	Acceptable (*)	Kuroki et al. [15]	Cochet et al. [13]	Nakatani et al. [14]	Blockhause et al. [16]	Maurhofer et al. [16]
Selection
Representativeness of the exposed cohort?	Truly or somewhat representative of the average patient referred for ablation	*	*	*	*	*
Selection of the non-exposed cohort?	Drawn from the same community as the exposed cohort	*	*	*	*	*
Ascertainment of exposure?	Secure record	*	*	*	*	*
Demonstration that outcome of interest was not present at start of study?	Yes	*	*	*	*	*
Comparability
Study controls for antiarrhythmic drug use?	Yes	-	-	-	-	-
Study controls for at least 3 additional factors?	Age, sex, HTN, HLD, DM, CAD, CVA/TIA	-	-	-	-	*
Outcome
Assessment of outcome?	Independent blind assessment or record linkage	-	-	-	-	-
Was follow-up long enough for outcomes to occur?	Yes	-	*	*	*	*
Adequacy of follow up of cohorts?	Complete follow up or subjects lost to follow up unlikely to introduce bias	*	*	*	*	*
Overall quality score (maximum = 9)		5	6	6	6	7

Abbreviations: AF, atrial fibrillation; CAD, coronary artery disease; CVA, cerebral vascular accident; DM, diabetes mellitus; HLD, hyperlipidemia; HTN, hypertension; TIA, transient ischemic attack