Lucia M Li1, Diederik O Bulters, Ramez W Kirollos. 1. Division of Neurosurgery, Addenbrooke's Hospital & University of Cambridge, Hills Road, Cambridge, CB2 0QQ, UK. lml34@doctors.org.uk
Abstract
BACKGROUND: Although rupture of intracranial aneurysms carries high mortality and morbidity rates, the clinical and financial benefit of screening certain high-risk groups is uncertain. We designed a mathematical model to interrogate the clinical benefit and cost-effectiveness of screening. METHODS: A decision tree analysis model was used to calculate the outcome and cost of two scenarios applied to the same population: one-off screening for intracranial aneurysms versus not screening. Each scenario had an associated gain or loss of Quality Adjusted Life Years (QALY) and cost; the difference between the two scenarios was calculated. The variable inputs were the aneurysm prevalence and risk of rupture after 5 years. Sensitivity analyses were performed to determine the effects of altering various factors on outcomes. RESULTS: Screening of the asymptomatic general population results in a QALY loss, equating to a negative clinical impact. The threshold 5-year risk of rupture at which screening resulted in a gain in QALYs was 13 %. This held true for any prevalence between 1 and 25 %. Risk of rupture had a greater impact on outcome than prevalence. Halving the risk of intervention (either surgery or coiling) reduced the threshold 5-year risk of rupture at which screening results in gain of QALYs to 6 %. The age of screening also had important effects on outcome. CONCLUSIONS: The QALY benefit and cost-effectiveness of screening are most sensitive to the 5-year risk of rupture. Screening is beneficial only in populations with a high risk of rupture; this should be the focus of future research.
BACKGROUND: Although rupture of intracranial aneurysms carries high mortality and morbidity rates, the clinical and financial benefit of screening certain high-risk groups is uncertain. We designed a mathematical model to interrogate the clinical benefit and cost-effectiveness of screening. METHODS: A decision tree analysis model was used to calculate the outcome and cost of two scenarios applied to the same population: one-off screening for intracranial aneurysms versus not screening. Each scenario had an associated gain or loss of Quality Adjusted Life Years (QALY) and cost; the difference between the two scenarios was calculated. The variable inputs were the aneurysm prevalence and risk of rupture after 5 years. Sensitivity analyses were performed to determine the effects of altering various factors on outcomes. RESULTS: Screening of the asymptomatic general population results in a QALY loss, equating to a negative clinical impact. The threshold 5-year risk of rupture at which screening resulted in a gain in QALYs was 13 %. This held true for any prevalence between 1 and 25 %. Risk of rupture had a greater impact on outcome than prevalence. Halving the risk of intervention (either surgery or coiling) reduced the threshold 5-year risk of rupture at which screening results in gain of QALYs to 6 %. The age of screening also had important effects on outcome. CONCLUSIONS: The QALY benefit and cost-effectiveness of screening are most sensitive to the 5-year risk of rupture. Screening is beneficial only in populations with a high risk of rupture; this should be the focus of future research.
Authors: Henry D Lather; Heather L Gornik; Jeffrey W Olin; Xiaokui Gu; Steven T Heidt; Esther S H Kim; Daniella Kadian-Dodov; Aditya Sharma; Bruce Gray; Michael R Jaff; Yung-Wei Chi; Pamela Mace; Eva Kline-Rogers; James B Froehlich Journal: JAMA Neurol Date: 2017-09-01 Impact factor: 18.302