Health Economic Evaluation Of Stroke Screening Strategy Using Decision Tree Markov Model

ObjectiveStroke is a chronic disease that has brought increasingly burden of disease for Chinese population.Screening of high-risk groups and control of risk factors are important preventive measures for stroke.The Stroke Screening,Prevention and Treatment Project(SSPP)had been started by the Ministry of Health of the Peoples’ Republic of China in 2011.However,there is no study to confirm whether the stroke screening strategy in SSPP is Cost-effectiveness.Our study is aimed to compare the cost-effectiveness of different stroke screening strategies by Markov model.MethodsUsing Tree Age Pro 2011 software to build a Markov model of the natural history of stroke disease and a decision tree-Markov model of high-risk population screening strategies.We simulated the progress of stroke in 100,000 healthy Chinese aged 40 years in 50 years.The parameters required by the Markov model(state transition probability,cost parameters,and utility parameters)come from the global disease burden research,stroke screening project workbook,and relevant published literature at home and abroad.There were three screening strategies in the screening model: unscreened,questionnaire(risk assessment questionnaire for high-risk groups of strokes)+ ultrasound(carotid artery ultrasound)and ultrasound screening strategy.There were three screening frequencies for each strategy,which were once a year,once every two years,and once every three years.Combining the cost parameters of each strategy,we calculate the cost-effectiveness,cost-utility,and net benefit of each strategy,and select the optimal strategy based on the willingness to pay.Finally,one-way and probability sensitivity analysis were performed on the parameters to explore the sensitive factors that have an impact on the choice of optimal strategy.ResultsThe results showed that compared with the absence of stroke screening,the effectiveness of each screening strategy was improved,including: the number of stroke cases(without screening vs screening,10,420 cases vs 6834-6870 cases),the number of deaths from stroke(without screening vs screening,8368 vs.4669 ～ 4991)and life years(LY)(increased from 1.1591 to 1.7999 million LY)and quality-adjusted life years(QALY)(increased from 1.1590 to 1.3830 million QALY).The annual,biennial,and triennial questionnaires + ultrasound screening strategy need cost 1081.48 yuan,1475.85 yuan and 1440.29 yuan for each unit of QALY obtained.The cost effectiveness of this strategy was lower than other strategies.Compared with the no-screening strategy,the annually questionnaire + ultrasound screening strategy requires the lowest cost for each additional unit of QALY,the incremental cost utility ratio(ICUR)was 1037.79 yuan / QALY,the ICUR of the triennially questionnaire ultrasound was 1916.98 yuan / QALY.The ICUR of the two screening strategies were lower than China’s GDP per capita in 2018(64,644 yuan / QALY).In addition,the net monetary benefit and net health benefit of the triennially questionnaire + ultrasound were higher than other strategies,which were 6.485 million yuan and 33.51 QALY,respectively.The triennially questionnaire + ultrasound was the most cost-effectiveness than others.Sensitivity analysis showed that the main factors affecting the selection of the optimal screening strategy were the discount rate and the carotid artery stenosis utility value.ConclusionIn this study,we found that screening high-risk groups for stroke was costeffectiveness.Compared with other screening strategies,the triennial questionnaire + ultrasound screening strategy was the most cost-effective of stroke screening for the Chinese over 40 years old.The triennial questionnaire + ultrasound method was the best strategy for stroke high-risk screening.Policy makers can apply this screening strategy to stroke high-risk screening and formulate relevant measures based on it.