Impact Of Capitation On Outpatient Expenses Among Patients With Diabetes Mellitus In Tianjin

Objectives: Capitation,which was implemented in a secondary hospital on January 1,2014 in Tianjin,China,aimed to control unreasonable increases in medical costs.The goal of the study was to evaluate the impact of capitation on outpatient expenses among patients with DM and provide scientific evidence for health policy-makers.Methods: 1.The samples were drawn out from Tianjin Health insurance database.The basic characteristics and outpatient expenses were described statistically.2.In this study,patients with DM who participated in the capitation were in the pilot group,which was compared to a control group sampled from the remaining hospitals using the “outpatient special diseases” insurance policy.Propensity score matching(PSM)and difference-in-differences(DID)analysis were combined to evaluate the policy.(1)Multivariate logistic regression was used to analysis influencing factors of participation in capitation.Multiple linear regression was used to analysis influencing factors of outpatient expenses.PSM was performed to create comparable intervention and control groups,which were paired 1:1 by using nearest neighbor matching.The balance was evaluated by comparing standardized differences in the means(SDM).(2)The records from 2013 were traced back according to the outpatient number after PSM.We estimated the impact of capitation reform on outpatient expenses through DID analysis.4.Two sensitivity analyses were used to evaluate stability of results.First,log-transformed expenses as dependent variables were subsumed into DID models to evaluate whether the analyses were biased by skewed data.Second,the control group was sampled from other secondary hospitals.Results: 1.A total of 409 257 records of patients with DM were included in 2013.Among them,205 119 records were male(50.12%).The average age was 60.62±10.74 years.The prevalence of complications related to DM is 50.09%(205 014 records).There were 350 411 records of urban employees(85.62%).The prevalence of patients in different hospital grades were as follows: 37.59% in primary hospital(153 860 records),27.87% records in secondary hospital(114 045 records),and 34.54% in tertiary hospital(141 352 records).In 2013,the total outpatient costs of DM in Tianjin were 2.818 billion yuan.Drug expenses accounted for 91.63%.A total of 464 066 records of patients were included in 2014.Among them,235 100 records were male(50.66%).The average age was 60.83±10.73 years.The prevalence of complications related to DM is 50.16%(232 763 records).There were 392 907 records of urban employees(84.67%).The prevalence of patients in different hospital grades were as follows: 34.39% in primary hospital(159 615 records),29.30% records in secondary hospital(135 957 records),and 36.31% in tertiary hospital(168 494 records).In 2014,the total outpatient costs of DM were 3.269 billion yuan.Drug expenses accounted for 92.35%.2.Records from the pilot group and control group in 2014 were paired based on confounding factors including gender,age,number of complications,type of medical insurance,and hospital grade.There were 4 907 patients in each group.Observed covariate balances were satisfied after matching due to SDM less than 0.1.Therefore,the two groups have been satisfied with approximate randomization.3.The records from 2013 were traced back according to the outpatient number.Eventually,there were 22 711 records included in the DID model.The annual drug expenses of pilot group were 2 153.21Yuan(95% CI:1 779.68-2 526.74)higher than control group.Annual examination expenses were 57.28 Yuan(95% CI:27.24-87.32)higher.Treatment expenses were 3.64 Yuan(95% CI:0.03-8.16)higher.Other outpatient expenses were 49.99 Yuan(95% CI:30.80-69.19)higher.Total outpatient expenses were 2 264.58 Yuan(95% CI:1 861.92-2 667.25)higher.4.Results of two sensitivity analyses indicated outpatient expenses of patients enrolled in capitation increased significantly which were consistent with the main model.Conclusion: 1.Compared with control group,outpatient expenses of pilot group increased significantly.The increases were due to the characteristics of policy.2.It is suggested to establish a competitive mechanism,strengthen supervision and improve the capitation policy in order to ensure that the treatment of DM can be facilitated while the medical expenses are effectively controlled.