ABSTRACT
OBJECTIVE：To know about the research status of health utility value obtained by mapping method in pharmacoeconomic evaluation ，and to provide reference for bibliometric study in pharmacoeconomic evaluation . METHODS ： Using“Mapping method ”“Health utility value ”“Cost-utility”“Utility point system ”as Chinese and English keywords ，retrieved from CNKI ，Wanfang database ，PubMed，Medline，Ebsco，Ovid and Wiley database ，empirical journal documents published from the inception to Dec. 31st，2018 about using mapping method to obtain health utility value were collected. The bibliometrics was used to statistically analyze basic information of included literature ，the construction and test of the model ，the type of the best model and so on. RESULTS ：The 124 included documents were all published in English journal. In the construction and testing of the mapping model ，the most frequently used econometric methods ，performance evaluation indicators and model testing methods were ordinary least squares （OLS），mean absolute error （MAE）and residual normality test ，application frequency of which were 97 times（31.60％），89 times（24.93％）and 62 times（21.09％）. There are 117 articles that define the best mapping model ，of which 101 articles（86.32％）have the best direct mapping effect. Most of the non-utility measurement scales adopted specific scales （92 articles，77.97％），and a few literatures adopted the universal scale （26 articles，22.03％）. The most utility measurement scales were 3-level European 5-dimensional health scale （79 articles，66.95％）. CONCLUSIONS ：The domestic empirical researches that use the mapping method to obtain health utility values need to be developed yet. A series of mapping models successfully developed by foreign scholars not only provide the feasibility of using non-utility measurement scales for cost-utility analysis ，but also provide more ideas for China to choose the corresponding econometric methods ，evaluation indicators and mapping methods in the empirical research of the mapping method in the future.
ABSTRACT
OBJECTIVE:To provide methodological reference for converting non-utility scale measurement results into health utility values. METHODS:Referring to domestic and foreign literatures,mapping methods and relevant models in health utility measurement were summarized. The effect of each model on probability mapping was introduced by taking the Medical outcomes study 12-item short form health survey measurement results converting into the EuroQol group's 5-domain utility values as exam-ple.RESULTS:The mapping methods can be adopted to obtain the health utility values by establishing the mapping relationship be-tween non-utility scale and utility scale. The common models included ordinary least square(OLS)model,censored least absolute deviations(CLAD)model,Tobit model,multinomial Logistic regression(MNL)model,Bayesian networks(BN)model,etc. OLS model was relatively simple with a good predictive validity,but it would be limited by the ceiling effect;Tobit model was not limit-ed by the ceiling or floor effect,when the error term satisfied the variance homogeneity and normality,prediction result of Tobit model was better than OLS model;CLAD model can be used for the situation of Tobit model unsuitable for non-variance homoge-neity of the error term;MNL model firstly determined a health state by regression analysis and then determined its utility value;the prediction validity of BN model was good and it didn't involved many assumptions and restrictions condition in econometrics, but the construction of BN model was greatly influenced by domain experts. Main methods for the calculation of health utility value with MNL or BN model were Monte Carlo simulation method,expected-utility method,most-likely probability methed,etc. We can carry out the model performance evaluation by using the R2,the adjusted R2,the mean error,the mean squared error and the mean absolute error,and then select the optimal model to calculate health utility values. CONCLUSIONS:Due to the advantages and disadvantages of each mapping model,it is necessary to select different mapping models based on the actual conditions.
ABSTRACT
OBJECTIVE:To provide methodological reference for converting non-utility scale measurement results into health utility values. METHODS:Referring to domestic and foreign literatures,mapping methods and relevant models in health utility measurement were summarized. The effect of each model on probability mapping was introduced by taking the Medical outcomes study 12-item short form health survey measurement results converting into the EuroQol group's 5-domain utility values as exam-ple.RESULTS:The mapping methods can be adopted to obtain the health utility values by establishing the mapping relationship be-tween non-utility scale and utility scale. The common models included ordinary least square(OLS)model,censored least absolute deviations(CLAD)model,Tobit model,multinomial Logistic regression(MNL)model,Bayesian networks(BN)model,etc. OLS model was relatively simple with a good predictive validity,but it would be limited by the ceiling effect;Tobit model was not limit-ed by the ceiling or floor effect,when the error term satisfied the variance homogeneity and normality,prediction result of Tobit model was better than OLS model;CLAD model can be used for the situation of Tobit model unsuitable for non-variance homoge-neity of the error term;MNL model firstly determined a health state by regression analysis and then determined its utility value;the prediction validity of BN model was good and it didn't involved many assumptions and restrictions condition in econometrics, but the construction of BN model was greatly influenced by domain experts. Main methods for the calculation of health utility value with MNL or BN model were Monte Carlo simulation method,expected-utility method,most-likely probability methed,etc. We can carry out the model performance evaluation by using the R2,the adjusted R2,the mean error,the mean squared error and the mean absolute error,and then select the optimal model to calculate health utility values. CONCLUSIONS:Due to the advantages and disadvantages of each mapping model,it is necessary to select different mapping models based on the actual conditions.
ABSTRACT
Brazilian scientists have been contributing to the protozoology field for more than 100 years with important discoveries of new species such asTrypanosoma cruzi and Leishmania spp. In this work, we used a Brazilian thesis database (Coordination for the Improvement of Higher Education Personnel) covering the period from 1987-2011 to identify researchers who contributed substantially to protozoology. We selected 248 advisors by filtering to obtain researchers who supervised at least 10 theses. Based on a computational analysis of the thesis databases, we found students who were supervised by these scientists. A computational procedure was developed to determine the advisors’ scientific ancestors using the Lattes Platform. These analyses provided a list of 1,997 researchers who were inspected through Lattes CV examination and allowed the identification of the pioneers of Brazilian protozoology. Moreover, we investigated the areas in which researchers who earned PhDs in protozoology are now working. We found that 68.4% of them are still in protozoology, while 16.7% have migrated to other fields. We observed that support for protozoology by national or international agencies is clearly correlated with the increase of scientists in the field. Finally, we described the academic genealogy of Brazilian protozoology by formalising the “forest” of Brazilian scientists involved in the study of protozoa and their vectors over the past century.