A cost‑utility analysis comparing endovascular coiling to neurosurgical clipping in the treatment of aneurysmal subarachnoid haemorrhage

Abstract

Endovascular coiling (EC) has been identifed in systematic reviews and meta-analyses to produce more favourable clinical
outcomes in comparison to neurosurgical clipping (NC) when surgically treating a subarachnoid haemorrhage from a ruptured
aneurysm. Cost-efectiveness analyses between both interventions have been done, but no cost-utility analysis has yet been
published. This systematic review aims to perform an economic analysis of the relative utility outcomes and costs from both
treatments in the UK. A cost-utility analysis was performed from the perspective of the National Health Service (NHS), over
a 1-year analytic horizon. Outcomes were obtained from the randomised International Subarachnoid Aneurysm Trial (ISAT)
and measured in terms of the patient’s modifed Rankin scale (mRS) grade, a 6-point disability scale that aims to quantify a
patient’s functional outcome following a stroke. The mRS score was weighted against the Euro-QoL 5-dimension (EQ-5D),
with each state assigned a weighted utility value which was then converted into quality-adjusted life years (QALYs). A sensitivity analysis using diferent utility dimensions was performed to identify any variation in incremental cost-efectiveness
ratio (ICER) if diferent input variables were used. Costs were measured in pounds sterling (£) and discounted by 3.5% to
2020/2021 prices. The cost-utility analysis showed an ICER of−£144,004 incurred for every QALY gained when EC was
utilised over NC. At NICE’s upper willingness-to-pay (WTP) threshold of £30,000, EC ofered a monetary net beneft (MNB)
of £7934.63 and health net beneft (HNB) of 0.264 higher than NC. At NICE’s lower WTP threshold of £20,000, EC ofered
an MNB of £7478.63 and HNB of 0.374 higher than NC. EC was found to be more ‘cost-efective’ than NC, with an ICER
in the bottom right quadrant of the cost-efectiveness plane—indicating that it ofers greater benefts at lower costs. This is
supported by the ICER being below the NICE’s threshold of £20,000–£30,000 per QALY, and both MNB and HNB having
positive values (>0).