Supplemental data:

Table e-1: Probabilities and distributions.

Variable / cases-population / Probability/year or
Probability/
event / Type of distribution / 95% CI(beta
distribution)
min-max (triangular distribution) / Source
Risk aneurysm development / - / 0.003-0.007 / uniform / - / (e1-e5)
Risk aneurysm is a ‘small aneurysm’ / - / 0.333-0.667 / uniform / - / (e6)
Risk aneurysm rupture for all but ‘small aneurysms’ / - / 0.01-0.02 / uniform / - / (e3, e7, e8)
Risk aneurysm rupture for
‘small aneurysms’ / - / 0.005-0.01 / uniform / - / (e9)
Risk aneurysm growth for ‘small aneurysms’ / 9-45 in ten years
4-18 in five years / 0.022-0.049 / uniform / - / (e1, e10-e12)
Risk death nursing home / 0.10-0-30 / uniform / - / (e13-e15)
Risk death other causes / age dependent / age dependent / 5 years / age dependent / (e16)
Risk death SAH / age dependent / age dependent / 10 years / age dependent / (e17)
Risk disability SAH / 168-1838 / 0.096 / beta / 0.083- 0.110 / (e18, e19)
Combined data
Risk death preventive coiling / 5-880 / 0.006 / beta / 0.002- 0.012 / (e20, e21)
Risk disability preventive coiling / 6-550 / 0.011 / beta / 0.004-0.021 / (e20, e21)
Risk death preventive clipping / 16-2253 / 0.007 / beta / 0.004-0.011 / (e22-e29)
Combined data.
Risk disability preventive clipping / 17-774 / 0.022 / beta / 0.013- 0.033 / (e23-e25, e28)
Combined data
Risk death DSA / 12-19826 / 0.0006 / beta / 0.0003-0.0010 / (e30)
Risk disability DSA / 27-19826 / 0.0014 / beta / 0.0009-0.0019 / (e30)
Risk MRA false-negative / 62-486 / 0.128 / beta / 0.099-0.159 / (e31)
Risk MRA false-positive / 30-364 / 0.082 / beta / 0.056- 0.113 / (e31)
Risk/probability aneurysm can be coiled / 55-74 / 0.743 / beta / 0.639-0.835 / (e32)
utility unscreened population / - / 0.83 / triangular / 0.76-0.90 / (e33, e34)
utility screen negatives / - / 0.87 / triangular / 0.82-0.93 / (e34)
utility screen positives / - / 0.73 / triangular / 0.63-0.83 / (e34)
utility after SAH / - / 0.64 / triangular / 0.52-0.71 / (e33)
utility nursing home resident / - / 0.31 / triangular / 0.29-0.34 / (e33)
Cost DSA* / - / 603 / - / - / (e35)
Cost MRA* / - / 267 / - / - / (e35)
Cost nursing home per year* / - / 77490 / - / - / (e36)
Cost treatment SAH* / - / 26561 / - / - / (e37)
Cost preventive clipping* / - / 8611 / - / - / (e35)
Cost preventive coiling* / - / 10046 / - / - / (e35)

* in 2007 euro

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