Health Economic Evaluation Of Screening For Diabetic Retinopathy Based On Markov Decision Model In Jiangsu Province

Objectives: Diabetic retinopathy(DR)is the leading cause of vision impairment and blindness in the working-age population(20-74 years old)around the world.The prevalence of DR is 18.45% among the Chinese diabetic population,and this figure in the rural population is higher than the urban population.DR screening meets the criterion of the World Health Organization(WHO)screening programme: a disease that progresses sequentially through identifiable stages,as a major public health problem,its screening and treatment methods are effective and acceptable.DR screening programs have been successively carried out in several areas of southern and northern Jiangsu since 2018.However,the health economics effects of the programs need to be further evaluated by economic evaluation.A markov decision model was developed to evaluate the effects of DR screening program for type 2 diabetic population in Jiangsu Province from the perspective of epidemiology and economics.Our study aims to provide the evidence in terms of economic evaluation for improving and promoting the screening strategy of DR,to explore the related factors affecting the quality of life of DR patients,and to provide information for health economic evaluation of DR and other related studies in the future.Methods: The subjects of this study are type 2 diabetic population and diabetic patients with DR in Jiangsu Province.The research data are mainly divided into five parts: published literature,the opinion of experts,screening reports of DR from grassroots workstations in Jiangsu Province,the investigation on the quality of life and medical costs of diabetic patients with DR,and official information.⑴ Data was collected through systematic literature review over multiple databases,including Pubmed,Scopus,Cochrane,Web of Science,China National Knowledge Infrastructure,Wan Fang Data and Chinese Biology Medicine,from inception to February 2021.All papers met selection criteria were included.Meta analysis were performed on annual transition probabilities obtained from Asian population studies,and pooled probabilities will be taken as parameters of Markov decision model.⑵ Based on the current screening mode of DR in Jiangsu Province,combined with the natural history of DR and the opinion of experts,the plan about screening,two-way referral and treatment of DR was determined.Tree Age Pro 2011 software was used to build corresponding Markov decision model,and relevant parameters were collected from multiple sources,cohort simulation method was used to simulate the disease course of DR among the study population under different interventions.Then cost-effectiveness analysis,cost-utility analysis and cost-benefit analysis of the research strategy were conducted according to the cohort simulation results.Finally,one-way,two-way and probabilistic sensitivity analysis were performed to evaluate the stability of the results.⑶ The quality of life data obtained from investigation was converted into health utility value using the value set based on Chinese three-level Euro Qol five-dimensional questionnaire.Tobit regression model and general linear model were selected to analyze and compare the influencing factors of health utility.Results: ⑴ A total of 15 follow-up studies are included eventually,8 of them are based on Asian population.Annual transition probabilities from 8 studies are pooled by different transition paths according to the results of heterogeneity test,the corresponding number of involved articles,pooled annual transition probabilities and 95% confidence interval are presented: from no DR to mild-to-moderate nonproliferative diabetic retinopathy(NPDR)[7 articles,0.055(0.038,0.079)];to severe NPDR[6 articles,0.007(0.004,0.013)];to proliferative diabetic retinopathy(PDR)[7 articles,0.004(0.002,0.009)].⑵ From the perspective of medical security,with a 3% discount rate,during the 30 years of DR screening in type 2 diabetic population in Jiangsu Province,compared with nonscreening group,the results of cost-effectiveness and cost-utility analysis show that the incremental costs per sight-year saved are 7,285.49 yuan,the incremental costs per life-year saved are 999,264.91 yuan,and the incremental costs per quality-adjusted lifeyear(QALY)saved are 13,312.57 yuan,respectively.Compared with the threshold level of willingness to pay(123,607yuan),the additional costs of the research strategy for sight saving years and QALYs are worthwhile,but not cost-effective for life saving years.The results of cost-benefit analysis show that the net present value of the research strategy is 34,523.00 yuan,and the benefit-cost ratio is 9.28,indicating that the strategy is cost-benefit.The results of sensitivity analysis show that "hazard ratio for diabetic macular edema(DME)in PDR patients who had accept delay/early photocoagulation ","utility of blindness" and "transition probability from PDR to DME" are three most influential parameters on the incremental cost-utility ratio,but corresponding upper limits of these three ratios are all lower than the threshold level of willingness to pay.⑶ The quality of life of DR patients is significantly lower than that of type 2 diabetic patients without complications(p<0.0001).And the general linear model combined with robust standard error shows a better fitting result in the multivariate analysis of utility than Tobit regression model.The result of general linear model shows that longer duration of diabetes mellitus,more chronic diseases and lower level of physical activity are related to the decrease of quality of life in DR patients.Conclusion: ⑴ In Asian patients with type 2 diabetes mellitus,the progression of DR is relatively slow in the nonproliferative stage.But as the disease progressed,the speed of progression is also accelerated.Therefore,early detection,diagnosis and treatment of DR are of great significance.⑵ Compared with nonscreening,DR screening programme carried out in type 2 diabetic population is cost-effective,cost-utility in terms of sight saving years and QALYs.The findings suggest that the programmme of DR screening and two-way referral of DR patients proposed in this study is worthy of promotion in the whole province.⑶ Compared with type 2 diabetic patients without complications,people with DR have a worse quality of life.Systematic health management such as the prevention and treatment of other diabetic complications,moderate exercise is helpful to improve the quality of life of patients of DR.