Table 3 A table summarising the Newcastle-Ottawa Quality Assessment Scale judgements made for the cohort studies included in this review

 Representativeness of exposed cohort

*

*

 Selection of the non-exposed cohort

*

 Ascertainment of exposure

*

*

*

 Demonstration that outcomes of interest were not present at start of study

*

 Comparability of cohorts on the basis of the design or analysis controlled for confounders (other factors incl. Patient demographics, severity of disease, embolisation procedure)

**

 Assessment of outcome

*

*

*

 Was follow-up long enough for outcomes to occur

*

*

*

 Adequacy of follow-up of cohorts

*

*

*

Total Newcastle-Ottawa Score:

5

8

5

AHRQ Judgement:

Poor quality

Good quality

Poor quality