Purpose: The number of elderly patients with subarachnoid hemorrhage (SAH) increases with the aging of the population. The prognosis of these patients is poor. Also, age is an important risk factor for complications from aneurysm occlusion by endovascular coiling or neurosurgical clipping. Whether age alone should be a factor precluding eligibility for aneurysm treatment is unknown. We studied which subgroups of elderly patients may benefit from aneurysm occlusion.

Methods: A decision analysis was performed, using a Markov model. Forty-eight subgroups of geriatric patients were defined, based on age (70-74,75-79,80-84,85+ years), neurological condition at admission (poor-grade, good-grade), day of admission after onset of SAH (<4, 4-10, 11-21 days), and gender. The health gains and costs incurred by aneurysm occlusion were estimated separately for each subgroup, with and without taking into account excess mortality due to competing risks. In addition, the incremental cost-effectiveness ratio (ICER) of occlusion compared with conservative treatment was estimated.

Results: Without accounting for competing risks, aneurysm occlusion resulted in health gains for all subgroups of patients. For patients admitted in poor condition (poor-grade) health gains ranged from 0.08-0.40 QALYs, with the corresponding additional costs ranging from € 11,475 to € 21,398 (ICER range € 47,784/QALY to € 145,718/QALY). In patients admitted in good condition (good-grade) occlusion dominated conservative treatment for women aged 70-79 years and for men aged 70-74 years, regardless of day of admission (ICER range for men aged 74-79 years € 11,968/QALY to € 19,881/QALY). With competing risks, domination occurred only for good-grade women aged 70-74 years, and for all subgroups the ICER increased considerably (average increase € 12,998/QALY. For poor-grade patients additional costs and health gains decreased while for good-grade patients additional costs increased and health gains decreased. In general, costs increased and health gains decreased with increasing patient age. Costs also increased with day of admission in good-grade patients but not in poor-grade patients.

Conclusions: Occlusion of ruptured intracranial aneurysms instead of conservative treatment is likely to improve outcome in elderly patients. Occlusion is highly cost-effective, and may be cost-saving, in good-grade patients up to the age of 80 years. Treatment of poor-grade patients, or patients aged 80 years or older, is not cost-effective.

This study was supported by the Netherlands Heart Foundation (grant # 2006B082).