Research On Statistical Modeling In Syndrome Of Traditional Chinese Medicine Of HIV/AIDS

Study of HIV/AIDS in Chinese medicine field is being concerned more and more for no effective therapies to cure HIV/AIDS in recent years.There have been many studies to explore the cause,pathogenesis and syndromes of HIV/AIDS,but so far an overall and systematic theoretical system has not been formed yet.Unclear distribution regularity of syndrome of traditional Chinese medicine and no standardization of criterion of syndromes of HIV/AIDS has become a bottleneck in the research of HIV/AIDS.In traditional syndrome differentiation,one syndrome was induced by clinical doctor from four diagnostic methods(inspection,listening and smelling,inquiry,palpation and pulse taking), then the relevant treatment was carried out on patients.Multivariate analysis is often used during this process to describe the quantificational relationship among those factors. Syndromes induced by clinical doctor are often non-measured directly and synthetic. Different clinical doctor might induce different syndromes on the same patient.How to identify distribution regularity and establish an objective and quantitative diagnostic criterion are the key points in study of syndrome of traditional Chinese medicine in HIV/AIDS.No breakthrough progress had not been achieved in many studies on syndromes of HIV/AIDS during the past 50 years,which had impacted the development of Chinese Medicine.Characteristics of syndromes of Chinese medicine and complexity of dataset which make it difficult to use traditional bio-statistical methods accounted for this situation. J(o|¨)reskog and Kessling applied the idea of path analysis into the latent variable research, combined with factor analysis and developed a new method-structural equation modeling (SEM).SEM is a complicated causal relationship model which can measure variables and possibly latent variables that have a causal structure.It has been widely used in many fields in recent 20 years.Diagnostics of disease in western medicine is to reveal basic regularity of disease.Combination of Traditional Chinese Medicine and Western Medicine and application of SEM to find out relationship between syndromes and four diagnostic methods can help to quantify the regularity of disease and provide objective basis for establishment of diagnostic criterion of syndromes of traditional Chinese medicine in HIV/AIDS.The most difficult problem in studying syndromes of traditional Chinese medicine are the complexity of data and hard to measure directly.A single method could not sort out such kind of problem,while combination of multiple methods by statistical modeling might sort out.This study aims to explore the relationship between regularity of syndromes of traditional Chinese medicine and four diagnostic methods(inspection,listening and smelling,inquiry,palpation and pulse taking),to investigate the main types of syndromes of traditional Chinese medicine in HIV/AIDS and construct its standard diagnostic criterion by using multiple correspondence analysis,multinomial logistic regression,exploratory factor analysis and structural equation model.Materials and methods1277 HIV/AIDS patients were interviewed with a self-made questionnaire including demographic characteristics,four diagnostic methods of Chinese medicine,syndrome of patients and index of laboratory examination using a multistage stratified random sampling technique.The reliability and validity of questionnaire was assessed.Statistical methods in this study included description of central tedndency and dispersion,univariate analysis, correspondence analysis,multinomial logistic regression,exploratory factor analysis and structural equation model.Statistical analysis of the data was performed by SPSS software (SAS 9.1),SPSS 15.0 and LISREL 8.54.Results1.Assessment of quality of questionnaire Cronbach's alpha was 0.63 and 0.79 respectively for the main and subordination syndrome items which indicated this questionnaire had a good construct validity and content validity.Missing values in index of laboratory examination ranged from 6.3%to 20.7%,which were imputed by expectation maximization algorithm.2.Univariate analysis The proportions of excess syndrome and syndrome of deficiency in HIV/AIDS were different(χ~2=54.37,P<0.01;χ~2=21.79,P<0.01). Syndrome of dampness-heat and accumulated toxin,syndrome of pathogens accumulation involving skin,syndrome of deficiency of lung and spleen qi were main syndromes of AIDS patients,while syndrome of dampness-heat accumulated interior,syndrome of liver and qi stagnation and syndrome of deficiency of spleen qi were main syndromes of HIV carrier.3.Correspondence analysis Correspondence analysis of tongue manifestation and pulse manifestation and excess syndrome and syndrome of deficiency had a good clearly differentiation index in two dimensions.Eigenvalue in two dimensions between tongue manifestation and basic excess syndrome or syndrome of deficiency was 0.149,0.097 or 2.603,1.801 respectively,and inertia in two dimensions was 2.680,1.752 or 0.145,0.100 respectively in HIV carriers.Eigenvalue in two dimensions between tongue manifestation and basic excess syndrome or syndrome of deficiency was 2.610,1.948 or 2.484,1.942 respectively,and inertia in two dimensions was 0.145,0.108 or 0.13 8,0.108 respectively in AIDS patients.Eigenvalue in two dimensions between pulse manifestation and basic excess syndrome or syndrome of deficiency was 2.024,1.327 or 2.017,1.288 respectively,and inertia in two dimensions was 0.202,0.132 or 0.202,0.129 respectively in HIV carriers.Eigenvalue in two dimensions between pulse manifestation and basic excess syndrome or syndrome of deficiency was 2.041,1.397 or 2.035,1.362 respectively,and inertia in two dimensions was 0.204,0.140 or 0.204,0.136 respectively in AIDS patients.4.Multinomial logistic regression Results of multinomial logistic regression showed that in HIV carriers,diarrhea(β=1.43,P=0.03)was related with syndrome of dampness-heat and accumulated toxin.Pruritus of skin(β=4.13,P<0.01),thin and short of sublingual vessel(β=2.04,P=0.02) and scratch-printed tongue(β=3.68,P<0.01) was related with syndrome of pathogens accumulation involving skin.Stringy pulse(β=1.75, P<0.01) was related with syndrome of liver and qi stagnation.Alopecia (β=0.81,P=0.04),teeth-printed tongue(β=1.36,P=0.02) and deep pulse (β=0.73,P=0.03) were related with syndrome of deficiency of spleen qi.Spiritlessness and weakness(β=2.60,P<0.01) were related with syndrome of deficiency of lung and spleen qi.Hypochondriac pain(β=2.42,P<0.01) and thin tongue(β=2.96,P<0.01) were related with deficiency of both qi and yin.Pale nail(β=1.67,P<0.03) was related with syndrome of deficiency of both qi and blood.In AIDS patients,greasy fur(β=1.34, P<0.01) was related with syndrome of dampness-heat accumulated interior.Tongue bleb (β=3.05,P<0.0l) and scratch-printed tongue(β=3.01,P<0.0l) were related with syndrome of pathogens accumulation involving skin.Emaciation(β=2.20,P=0.02), aversion to cold(β=2.28,P<0.01) and thready pulse(β=1.17,P<0.01) were related with syndrome of deficiency of spleen qi.Fever(β=2.13,P=0.07) was related with deficiency of both qi and yin.5.Factor analysis KMO was 0.84,which indicated a good a measure of sampling adequacy in HIV carriers.Bartlett's test of sphericity showed that correlation was appropriate for factor analysis(χ~2=2193.87,P<0.01).Based on extraction retains factors with eigenvalues >0.8,12 factors were extracted with cumulative loading of 68.27%。KMO was 0.86 in AIDS patients,Bartlett's test of sphericity was significant(χ~2=2592.68, P<0.001).12 factors were extracted with cumulative loading of 69.99%(eigenvalues >0.8) in AIDS patients.6.Structural equation model Among excess syndrome,syndrome of liver and qi stagnation was main syndrome of HIV carriers,and syndrome of pathogens accumulation involving skin was main syndrome of AIDS patients.The following goodness indexes of fit Statistics of SEM related with Chinese Medicine excess syndrome showed a good fit: Minimum Fit Function(χ~2=985.26,P<0.01).Root mean square error of approximation (RMSEA)=0.070,Non-Normed Fit Index(NNFI)=0.84,Comparative Fit Index(CFI)= 0.87,Incremental Fit Index(IFI)=0.87,Goodness of Fit Index(GFI)=0.92 and Adjusted Goodness of Fit Index(AGFI)=0.89.Among syndromes of deficiency,syndrome of deficiency of spleen qi was main syndrome of HIV carriers,and syndrome of deficiency of lung and spleen qi was main syndrome of AIDS patients.The following were Goodness indexes of Fit Statistics of SEM related with Chinese Medicine syndrome of deficiency, and indicating a good fit of SEM.Minimum Fit Function(χ~2=768.90,P<0.01),Root Mean Square Error of Approximation(RMSEA)=0.088,Non-Normed Fit Index(NNFI)=0.82, Comparative Fit Index(CFI)=0.86,Incremental Fit Index(IFI)=0.86,Goodness of Fit Index(GFI)=0.92 and Adjusted Goodness of Fit Index(AGFI)=0.88.Conclusion1.HIV/AIDS has four main excess syndrome and four main syndrome of deficiency: syndrome of dampness-heat accumulated interior,syndrome of dampness-heat and accumulated toxin,syndrome of pathogens accumulation involving skin,syndrome of liver and qi stagnation,syndrome of deficiency of spleen qi,syndrome of deficiency of lung and spleen qi,syndrome of deficiency of both qi and yin,syndrome of deficiency of both qi and blood.Syndrome of dampness-heat and accumulated toxin,syndrome of pathogens accumulation involving skin,syndrome of deficiency of lung and spleen qi are main syndromes of AIDS patients.Syndrome of dampness-heat accumulated interior,syndrome of liver and qi stagnation,syndrome of deficiency of spleen qi are main syndromes of HIV carriers.Quantitative relationship between syndromes and four diagnostic information can provide basis for establishing diagnostic criterion of syndromes of traditional Chinese medicine in HIV/AIDS.2.Corrrespondence analysis is appropriate for exploring relationship between tongue manifestation,pulse manifestation and syndromes.Multinomial logistic regression is more powerful in exploring the influence of four diagnostic information on syndromes. Exploratory factor analysis is better in analyzing latent variables which influence the main syndromes of AIDS.All those methods are appropriate and valuable.3.Confirmatory factor analysis and SEM can be used to validate the structure and causal relationship between syndromes of AIDS and four diagnostic information,to study relationships between different type of syndrome(latent variables).4.Any single statistical method can not study the syndromes of AIDS.Combination of different kinds of statistical method and suggestion of clinical doctors can be used as a powerful tool.