Descriptive Epidemiology Investigation And Analysis Of The Rare Disease In Eight Provinces, China

Background: Rare disease is a chronic or life-threatening disease. At present, there is no uniform definition of rare diseases around the world. World Health Organization(WHO) defines the disease prevalence accounted for 0.65‰ to 1‰ of the total population for rare diseases. Our country from the aspect of drug economics, the definition of as rare disease is that the affected number of people by diseases accounted to 300000-500000 population. In China the incidence of rare diseases, the prevalence rate and the epidemiological data generated by the disease burden of disease is still lacking. Rare disease epidemiological data has profound significance for the development of orphan drug and development health policy.Aimes: Through a sample survey from Shandong, Anhui, Zhejiang, Jiangxi, Henan, Hebei Province and Xiamen City seven provinces' 100 hospitalization data to select rare diseases. We use the DISMOD? software to estimate rare disease prevalence and burden of disease. The method provides a reference to calculating other epidemiological data for China rare disease. At the same time, these epidemiological data provide the reference to developing orphan drugs and health policy for rare diseases.Methods: According to the rare disease directory published in Orphanet, we regard the ICD code or rare disease names as keywords to select rare diseases from hospitalization data. The hospitalization data included the name of rare disease, gender, age, date of hospitalization, the date of discharge. Putting the hospital patient of rare disease data as molecular, the sixth census population in the study area as the denominator calculate incidence of rare disease. From published literature, we obtain disease remission rate. According to the American rare disease mortality, we used relevant statistical methods to calculate rare disease mortality in China. Finally, we put the relevant indicators, the national mortality data and population data divided by age and gender ground into DISMOD? model to calculate the disease prevalence, burden of disease and other epidemiological data.Resluts: According to the directory of rare disease name(4299) and ICD code(1049), from 17679186 hospitalized patients in 100 hospitals, 8 provinces, we select 952 kinds of rare diseases, totaled of 392429 cases of rare diseases. The kinds of the congenital malformation, deformation, and chromosomal abnormalities diseases accounted 38% of the surveyed kinds of diseases by epidemiological survey. Endocrine, nutritional and metabolic disorders and the nervous system of diseases respectively, accounted for 15% and 11%. We performed a statistic of the number of cases and found that 40% of the diseases are less than 10 cases of disease number; 75.9% of the diseases are less than 100 cases number, 11% kinds of disease accounted for investigation diseases are more than 1000 cases. By the epidemiological investigation, we found that 10 kinds of rare diseases with large number of cases are anal fistula and cleft palate, congenital egg round hole arteriosus, hydatidiform mole, Evans syndrome, syndrome, trigeminal neuralgia, polycystic kidney preeclampsia, cleft lip, Guillain Barre syndrome.Using the DISMOD ? software, we estimate 38 kinds of rare diseases' prevalence, such as scleroderma, osteogenesis imperfecta, patent ductus arteriosus, cleft lip, Kawasaki disease, autosomal recessive polycystic kidney disease, multiple system atrophy, cleft palate, tetralogy of Fallot, pulmonary hypertension, Felty syndrome, anal atresia, Guillain Barre syndrome, obstructive hydrocephalus, spinal cord isolated injury, spina bifida, sarcoidosis, antidiuretic hormone deficiency, hemophilia A, Sheehan syndrome, von Willebrand disease, paroxysmal nocturnal hemoglobinuria, myasthenia gravis, epidermolysis bullosa, pericarditis, Cushing syndrome, Langerhans cell histiocytosis, Marfan syndrome, Meniere's disease, central diabetes insipidus, Evans syndrome, renal dysplasia and esophageal atresia and Down syndrome, glycogen storage disease, Wegener's granulomatosis, congenital coagulation Blood factor deficiency, hepatolenticular degeneration. According to the calculation of the DISMOD? software, we used the calculated rare disease prevalence and the number of 38 kinds of hospitalization to calculate a constituent ratio to estimate the number of 952 kinds of rare disease about 16089589. According to the epidemiological parameters DISMOD? calculated, and obtained from relevant literature using the WHO global burden of disease calculation method, we compute 10 kinds of rare disease burden, like scleroderma, multiple sclerosis, numerous gravis, Down's syndrome, osteogenesis imperfecta, cleft lip, cleft palate, anal atresia, atresia of esophagus, kidney insufficiency, respectively 2.8DALYSs/100000, 3.32 DALYSs/100000, 2.23 DALYSs/100000, 8.2 DALYSs/100000, 1.2 DALYSs/100000, 0.29 DALYSs/100000, 0.07 DALYSs/100000, 0.18 DALYSs/100000, 0.08 DALYSs/100000, 0.56 DALYSs/100000, 0.18 DALYSs/100000. The burden of disease(YLDs) is higher than the burden caused by death(YLDs).Conclusions: According to the catalogue of rare diseases, the 4299 rare disease name and 1049 ICD-10 coding as the key word, we use SQL Sever 2008 to search hospitalized patients from rare disease database, including Shandong Province, Anhui Province, Zhejiang Province, Jiangxi Province, Henan Province, Hebei Province and Xiamen hospitals' hospitalization. We found that there were 952 kinds of data from 100 hospitals in 6 provinces and Xiamen city. The number of hospitalized patient of rare disease patients showed a rising trend. The congenital malformation, deformation, and chromosomal abnormalities, endocrine, nutritional and metabolic disorders and diseases of the nervous system are accounted for the investigation of the found that 64% of the kinds of diseases. A large number of 10 kinds of rare diseases are anal fistula and cleft palate, congenital egg round arteriosus, hydatidiform mole, Evans syndrome, syndrome, trigeminal neuralgia, polycystic kidney preeclampsia, cleft lip, Guillain Barre syndrome.According to the epidemiological survey, with inpatient number of rare disease patients using DISMOD?, we calculated 38 kinds of rare diseases' prevalence. Using the 38 kinds of rare disease, we calculate a constituent ratio to estimate the 952 kinds of rare disease. There are about 16089589 rare disease patients in China. This investigation is focused on the central and eastern regions' inpatient data. Estimated incidence may be lower than the true incidence, so the calculated prevalence maybe as the lowest prevalence rate. So rare disease actual prevalence number is much higher than that we select by epidemiological survey.According to the DISMOD? output epidemiological data and disability weights obtained from published literature, we calculated 10 kinds of diseases' disease burden, such as scleroderma, multiple sclerosis, heavy myasthenia gravis, etc. YLDs are higher than that of YLLs. It highlighted that caused by disability health life year is higher than because of the resulting in the death of healthy life years. The main factor of the burden of disease is YLDs. In summary, in present in our country, we still lack the registration system of the rare disease. Through the investigation of hospitalized patient of rare disease to estimates of China's rare disease prevalence rate of the method is feasible and high reliability. The survey found that there are many kinds of rare disease in China and large number of rare disease patients. These rare diseases caused a serious disease burden. These epidemiological data could have important significance for the study of rare diseases in our country.