Background: Patients who have survived an episode of subarachnoid hemorrhage are at increased risk for a new episode from newly developed aneurysms (denovo or regrowth). We evaluated the cost-effectiveness of preventive screening strategies for these patients, specifically the effect of a lower quality of life for patients who fear recurrence and are not screened was assessed.

Methods: The strategies "no screening" and "life-long screening of all patients under the age of 70, every N^th year (N=2,5,10)" were compared using a Markov chain decision model. Hypothetical subgroups of patients at increased risk were defined, with relative risks [1.5...4.0] for the formation and rupture of aneurysms.

Results: Discarding disutility due to fear of recurrence screening always resulted in increased costs and a loss of quality-adjusted life years for patients with standard risk, making the "no screening" strategy dominant. Univariate sensitivity analyses indicated that the key parameters were the incidence and rupture rate of new aneurysms. For conservative annual rates of rupture (0.4% for denovo and 2% for regrowth aneurysms) screening strategies were not cost saving, not even for subgroups with a relative risk of 4.0. For annual rupture rates observed in the Netherlands (1.4% for denovo and 3.2% for regrowth aneurysms) a 5-year screening strategy resulted in cost savings for patients with a relative risk exceeding 1.8. However, screening this subgroup did not result in an increase in the expected number of quality-adjusted life years. Assigning different utilities to healthy patients in the screening group and the the "no screening" group had a profound impact on cost-effectiveness. A disutility exceeding 0.02, i.e. accounting for being reassured or not, resulted in cost savings and increased survival for the 5-year screening strategy, already for the low rupture rates.

Conclusions: Preventive screening of these patients is not cost-effective in general, however, for subgroups of patients at increased risk screening may be cost-effective. On patient-level the degree to which patients are burdened by the knowledge of increased risk of recurrence predominantly determines cost-effectiveness. Thus a paradox appears: not informing patients of their increased risk leaves screening redundant whereas informing patients may make screening highly preferred.