Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade y...Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade years. In this paper, many of models related to varying-coefficient models are gathered up. All kinds of the estimation procedures and theory of hypothesis test on the varying-coefficients model are summarized. Prom my opinion, some aspects waiting to study are proposed.展开更多
Malaria is one of the leading causes of consultation in African pediatric hospitals. In Gabon, malaria transmission is perennial. Plasmodium falciparum, responsible for the most severe form of the disease, represents ...Malaria is one of the leading causes of consultation in African pediatric hospitals. In Gabon, malaria transmission is perennial. Plasmodium falciparum, responsible for the most severe form of the disease, represents more than 95% of all species. In P. falciparum infection, the hyperparasitemia accounts among the main criteria of disease severity. However, in many endemic countries, a significant decrease of malaria burden accompanying with the diminution of parasite load in infected individuals has been demonstrated. The objective of the study was to analyze the occurrence of febrile syndrome in childhood and investigate whether the acute febrile illness could be associated with P. falciparum submicroscopic infection. A cross-sectional study was carried out during January to March 2013 in Franceville. A total of 203 acute febrile children were enrolled. A clinical examination and biomedical analysis including parasitological diagnosis by microscope were carried out in all the patients and PCR on microscope negative ones. Of 203 children recruited for febrile syndrome, 111 have been diagnosed positive for P. falciparum infection, 73 （35.9%） by microscope （ME） and 38 （18.71%） by PCR （submicroscopic infection = SM1） with an overall prevalence of 54.68%. Of the 11 1 P. falciparum infected individuals and according to the WHO criteria, 35 （31.53%） children showed a clinical picture of severe malaria against 76 （68.47%） others classified as uncomplicated malaria. The overall prevalence rates were therefore estimated as 17.24 （35/203） for severe cases and 37.43% （76/203） for uncomplicated ones. Clinically, these severe malaria cases （27 ME＋ and 8 PCR＋） were mainly composed of 85.71% of anaemic patients （30/35）, 71.14% of prostrated individuals （25/35） and 57.14% of children with clinical icterus （20/35）. However, only two cases of severe anaemia were observed, the remaining others cases were moderate （10） and mild anaemia （18）. More interestingly, eight submicroscopic infected patients （22.85%） were found with neurological manifestations （prostration） and all were experiencing thrombocytopenia. Lastly, 1 hyperparasitemia, 6 hypoglycemia and 2 respiratory distresses were also observed among these severe malaria cases. P. falciparum submicroscopic infection may lead to severe malaria in perennial transmission area.展开更多
In biomedical research,in order to evaluate the effect of a drug,investigators often need to compare the differences between one treatment group and another one by using multiple outcomes.The rank-sum tests can handle...In biomedical research,in order to evaluate the effect of a drug,investigators often need to compare the differences between one treatment group and another one by using multiple outcomes.The rank-sum tests can handle the case where the outcome differences between two groups are in the same direction.If they are not,MAX can handle it and is very useful when one/some of the differences is/are relatively larger than the others.When the individual outcome difference between two groups is moderate,a new method,summation of the absolute value of rank-based test for each outcome,is proposed in this work.Power comparison with the existing methods based on simulation studies and a real example show that the proposed test is a robust test,and works well when the difference for each outcome is moderate.The authors also derive some theoretical results for comparing the power between MAX and the the proposed method.展开更多
基金Foundation item： Supported by the National Natural Science Foundation of China（10501053） Acknowledgement I would like to thank Henan Society of Applied Statistics for which give me a chance to declare my opinion about the varying-coefficient model.
文摘Varying-coefficient models are a useful extension of classical linear model. They are widely applied to economics, biomedicine, epidemiology, and so on. There are extensive studies on them in the latest three decade years. In this paper, many of models related to varying-coefficient models are gathered up. All kinds of the estimation procedures and theory of hypothesis test on the varying-coefficients model are summarized. Prom my opinion, some aspects waiting to study are proposed.
文摘Malaria is one of the leading causes of consultation in African pediatric hospitals. In Gabon, malaria transmission is perennial. Plasmodium falciparum, responsible for the most severe form of the disease, represents more than 95% of all species. In P. falciparum infection, the hyperparasitemia accounts among the main criteria of disease severity. However, in many endemic countries, a significant decrease of malaria burden accompanying with the diminution of parasite load in infected individuals has been demonstrated. The objective of the study was to analyze the occurrence of febrile syndrome in childhood and investigate whether the acute febrile illness could be associated with P. falciparum submicroscopic infection. A cross-sectional study was carried out during January to March 2013 in Franceville. A total of 203 acute febrile children were enrolled. A clinical examination and biomedical analysis including parasitological diagnosis by microscope were carried out in all the patients and PCR on microscope negative ones. Of 203 children recruited for febrile syndrome, 111 have been diagnosed positive for P. falciparum infection, 73 （35.9%） by microscope （ME） and 38 （18.71%） by PCR （submicroscopic infection = SM1） with an overall prevalence of 54.68%. Of the 11 1 P. falciparum infected individuals and according to the WHO criteria, 35 （31.53%） children showed a clinical picture of severe malaria against 76 （68.47%） others classified as uncomplicated malaria. The overall prevalence rates were therefore estimated as 17.24 （35/203） for severe cases and 37.43% （76/203） for uncomplicated ones. Clinically, these severe malaria cases （27 ME＋ and 8 PCR＋） were mainly composed of 85.71% of anaemic patients （30/35）, 71.14% of prostrated individuals （25/35） and 57.14% of children with clinical icterus （20/35）. However, only two cases of severe anaemia were observed, the remaining others cases were moderate （10） and mild anaemia （18）. More interestingly, eight submicroscopic infected patients （22.85%） were found with neurological manifestations （prostration） and all were experiencing thrombocytopenia. Lastly, 1 hyperparasitemia, 6 hypoglycemia and 2 respiratory distresses were also observed among these severe malaria cases. P. falciparum submicroscopic infection may lead to severe malaria in perennial transmission area.
基金partially supported by by the National Young Science Foundation of China under No.10901155the National Social Science Foundation of China under No.10CTJ004
文摘In biomedical research,in order to evaluate the effect of a drug,investigators often need to compare the differences between one treatment group and another one by using multiple outcomes.The rank-sum tests can handle the case where the outcome differences between two groups are in the same direction.If they are not,MAX can handle it and is very useful when one/some of the differences is/are relatively larger than the others.When the individual outcome difference between two groups is moderate,a new method,summation of the absolute value of rank-based test for each outcome,is proposed in this work.Power comparison with the existing methods based on simulation studies and a real example show that the proposed test is a robust test,and works well when the difference for each outcome is moderate.The authors also derive some theoretical results for comparing the power between MAX and the the proposed method.
