Medical Cost And Its Heterogeneity In Chronic Hepatitis B Cohort By Latent Growth Mixture Modeling

ObjectivesChronic hepatitis B was one of the major public health problems in China,with a serious disease burden and medical costs have continued to increase over the years.The hospital-based chronic hepatitis B patient cohort can reflect the change of medical cost in the real environment,but the clinical patients have long disease duration,large differences in disease characteristics,treatment methods and medical expenses were relatively heterogeneous.Building the LGMM model based on the medical expenses data of the hospital HIS system,to explore the development trend of direct medical expenses of patients with chronic hepatitis B in Guangzhou during the long-term of diagnosis and treatment,and discuss the heterogeneity of medical expenses,in order to provide a scientific basis for clinicians to choose treatment options and formulate medical resource allocation strategies.MethodsThe medical expenses data of this study were obtained from the HIS system of an infectious disease specialist hospital in Guangzhou.The data included demographic characteristics,medical information,medication,medical expenses and its detailed expenses records,laboratory indicators of patients who were diagnosed with "chronic hepatitis B" at the hospital from January 1,2008 to December 31,2016.The latent growth mixture model was used to model the direct medical expenses of patients with chronic hepatitis B,the direct medical expenses and detailed cost components,drug use and treatment indicators among different subgroups were compared,to explore the relevant factors for the development trend of direct medical expenses of different subgroups.ResultsAmong the 2918 patients with chronic hepatitis B were enrolled in this study,males dominated(73.06%),average age were(34.29±10.72)years,and the percentage of self-paying patients was highest(50.41%),followed by medical insurance patients(42.19%),and the proportion of publicly funded patients was the lowest(7.40%).With the increase of treatment period,the annual direct medical expenses of patients with chronic hepatitis B initial treatment were gradually increasing.The annual direct medical expenses of male patients was higher than that of females(Z=32.05,P<0.001);With the increase of age,the annual direct medical expenses of patients showed an increasing trend(Z=42.66,P<0.001);the annual direct medical expenses of medical insurance patients were higher than Self-paying and publicly funded patients(Z=278.72,P<0.O01).The patients were identified three latent classes:"cost stable fluctuation group","increased cost group" and "slow cost reduction group",and the number of each class was 928(31.80%),1468(50.31%)and 522(17.89%)respectively.The "cost stable fluctuation group" was higher in males but the age distribution was mostly in the lower age group,and the proportion of patients with disease progression was 10.34%.The annual direct medical expenses of patients during the whole treatment period fluctuated at the starting point level,and finally at the middle cost level;In the "increasing cost group",males accounted for a high proportion and the age distribution was mainly in the high age group,and the number of patients with disease progression was the highest(19.28%).During the whole treatment period,the annual direct medical expenses of the patients gradually increased from the starting point level,and finally the high cost level.The "slow cost reduction group" females accounted for a relatively high proportion and the age distribution was mainly in the low age group,and the patients with the disease progressed the least(4.98%).The annual direct medical expenses of the patients decreased slowly from the starting point during the whole treatment period,and finally the low cost Level.Comparing the use of antiviral drugs in three subgroups,the"increased cost group" patients had the highest annual antiviral use rate,and the subgroup patients had the highest annual utilization rate of ETV,LAM and LDT(60.76%,31.61%and 33.11%).the annual utilization rate of patients of the "cost stable fluctuation group" was between other subgroups,while the "slow cost reduction group" patients had the highest IFN annual use rate(21.65%).The annual utilization rate of other type antiviral drugs were lower than the other subgroups.Comparing the laboratory indicators of the three subgroups,the baseline HBV DNA test was mainly distributed at a higher level in the"increasing cost group",while the "slow cost reduction group" baseline HBV DNA test in the<1.0×104 copies/ml accounted for the highest proportion(21.84%).There were no significant differences in the baseline ALT,HBeAg,and HBeAb among the three subgroups.Logistic regression results showed that the use of antiviral drugs in the first year of treatment reduced the risk of disease progression(P=0.098,OR=0.816);the use of interferon in the first year of treatment reduced the risk of disease progression(P=0.006,OR=0.350);the"increased cost group" patients were at higher risk of disease progression than those in the First subclass,while the "slow cost reduction group"patients were at lower risk of disease progression(P=0.006,OR=0.350;P=0.006,OR=0.525).C onclusionLatent growth mixture model can identify unobserved subgroups and their different medical expenses trajectories for the cohort of patients with CHB.LGMM identified three subgroups of direct medical cost growth patterns,and three subgroups of annual direct medical costs,use of antiviral drugs and laboratory indicator were differences.Only 50%of patients with chronic hepatitis B have a multi-year medical cost,and the disease progresses more seriously;The severity of baseline HBV DNA levels and early use of antiviral medications were the important factors of increased direct medical costs and disease progression.About 20%of patients with chronic hepatitis B have a slow decline in medical expenses for many years,and the rate of disease progression was lowly among these patients,the account of female for a higher proportion than other subgroups,and early interferon use rates were higher.Therefore,early use of interferon in the disease may delay disease progression and reduce further medical costs.