The evidence was initially of high quality but was downgraded
due to limitations in study design (mostly selection
bias), indirectness (outcomes were rarely reported) and
impreciseness (different magnitudes of predictive power of
risk factors between studies). However, the strength of the
recommendation was view as strong by the working
group, considering the seriousness of the complication
and health/economic impact of missing a patient with a
neurosurgical lesion. The working group also discussed
older age (≥60 years and ≥65 years) as well as antiplatelet
medication as risk factors of importance, partly due to the
presence of these criteria in other guidelines and decision
rules. However, the predictive ability was only moderate
and these individual risk factors would lead to an unacceptable
CT increase and so consensus was not to include
these in our recommendation.