The Application Of The Multivariable Analyze And Set Pair Analysis In The Study Of The Influencing Factors Of The Attitude Of The Medical University Students Toward The Premarital Sexual Behavior

Objective :While our cultural exchange with all over the world more and more extensive, "sex freedom", "sex liberation" idea of the west continuously influences the chinese youth. The university student's sex attitude gradually changed and the premarital sexual behavior also happens in an certain rate.The premarital sexual behavior not only influences the university student's study, but also makes the university student face of series problems both in physiology and mental.This research is further applied Set Pair Analysis(SPA),on the fundation of multi variable analysis, to analyze the uncertainty and the certainty of the the university student's sex attitude and find out the uncertainty of each factor, in order to provide some rational advice of the health education,which would help to reduce the premarital sexual behavior incidence rate.Methods:1 MaterialsFrom May to November in 2003,all of the calsses of undergraduate in Hebei Medical University,25 classes(746 students in total) were randomly sampled by cluster sampling to conduct a survey.2 The estimation of the sampling size.3 Statistical methods3.1 Evaluate the validity,relibility and acceptability of the questionaires.3.2 Q-type systemic clustering method is to classify the samples.3.3 Ordinal ploytomous logistic regression analysis3.3.1 Multicolinearity diagnosis for independent variables:the indexes of diagnosis are tolerance,VIF,eigenvalue and condition index.3.3.2 The test of parallel lines and likelyhoodχ2 test of every variable.3.3.3 Ordinal ploytomous logistic regression analysis Cumulative logit model is used to make ordinal ploytomous logistic regression analysis.Stepwise backward regression is used to select the independent varibles with both the inclusion criteria and exclusion criteria as 0.05.3.3.4 The test of the regression equationThe likelihood tatio test is used to test the regression equation; the Waldχ2 is used to test the independent variables; calculate the goodness of fit and Pseudo R-Square.3.4 Set Pair Analysis3.4.1 Calculate the twe element correlate of X1of every cluster.3.4.2 Calculate the three element correlate of X2 , X7 , X10 , X11 , X12 , X14 , X15of every cluster.3.4.3 Calculate the four element correlate of X3 , X4 , X5 , X6 , X8 , X9 , X13 , X16 , X17 of every cluster.Results:1 The general conditions of the materials. 746 students were inteviewed in total,732 questionnaires were handed back,and 724 of them were effective.The effective rate is 98.92%.2 The evaluation of the quetionnaires.2.1 The internal consistent reliability is 0.702, which indicates that the reliability of the quetionnaire is good.2.2 Through factor analysis ,the eigenvalue of the five common factors are more than 1, the cumulative contribution rate is 47.74%, and the factor loading of every term in the corresponded common factors is more than 0.4. These indicates that the construct validity of the questionnaires is good.2.3 All the students finished the questionnaires in 10 minutes.the callback rate is 98.12%,and the effective rate is 98.91%,which indicates that the acceptability of the questionnaires is good.3 The result of cluster analysisAll the samples are classified into 3 clusters,which are named as cluster I, cluster II and cluster III, respectively with the corresponding numbers of 494, 88 and 142.The feature of the 3 clusters:Cluster II: The ratio the male is the highest,the communist party number is the lowest, the family income is the highest, parents'education degree is the lowest. They feel the study is very burden, and the mumber of courses which are not qualified are the most. Their satisfactory extent to study and living is the lowest. The extent of family constraint is the least. Most of them consider that loving affairs on the campus will not influence study and their times of love affairs is the most. Their parents consent they fall in love. The premarial cohabipations around them are the most. They support sexual liberation and object to the chinese traditional chastity concept (Crowd A) .Cluster III'characteristic are exactly the opposite to cluster II (Crowd C) .Cluster I lies between the cluster II and the cluster III. (Crowd N)4 Oridinal plotomous logistic regression ananlysis4.1 Multicolinearity diagnosis for independent variables Independent variables'tolerances are all above 0.1, VIFs are all below 5, eigenvalues are all above 0, and condition indexes are all below 30.So there is no severe multicolinearity among the independent variables.4.2 The result of the test of parallel linesχ2=27.350,P=0.053,can satisfy the logit model.4.3 The result of the likelyhoodχ2 test of every variable. Variables X8, X9, X10 , X15 entry the regression equation as factors,while the other as covariates.4.4 Selecting variables: The stepwise backward regression is used to select variables. There are 13 variables are reserved in the regression equation. They are gender(X1), whether the member of the Communist Party (X2), the family income (X3), father'literary level(X4), mother'literary level(X5), how feel the study(X6), how many course are don't qulified(X7), parents' attitude in fall in love (X12), the attitude to the traditional chastity concept(X16), whether parents' upbringing is scathing(X11), whether content to the study and living envirment(X8), whether deen love would influnce study(X9), the attitude to the sexual liberation(X15).4.5 The test of the cumlative logit regression equation:likelihood testχ2=812.580 , P = 0.000, the equation is statistical significance. The logit regression equation is: Logit[P(Y≤1)]=αj-1.191X1+1.127X2+0.937X3-0.453X4-0.772X5 -0.426X6+1.313X7+1.764(X8=1)+2.050(X8=2) +0.705(X8=3)-2.133(X9=1)-2.386(X9=2) -1.169(X9=3)+0.405X11-0.518X12-1.277(X15=1) -0.258(X15=2)+1.209X16 j=1,2.α1=-1.870,α2=7.281According to the result of the cumulative logit regression analysis, 13 variables can be ranked according to their effects as: X9 , X8 , X16 , X7, X3 , X5 , X15 , X2 , X1 , X4 , X6 , X12 , X11.4.6 the result of the goodness of fit and Pseudo R-Square Pearsonχ2=1002.177 , P=0.468 ; Devianceχ2=295.780 ,P=0.999。Cox and SnellR2=0.668, NagelkerkeR2=0.817,McFaddenR2=0.649。5 The result of Set Pair Analysis5.1 Result of X1: the assentient crowd(Crowd A) is in the first grade of shi(H)P, the neutral crowd(Crowd N) and the conservative crowd(Crowd C) are all in the first grade of shi(H)S.5.2 Result of X2: Crowd A is in the forth grade of shi(H)P,while the other are all in the third grade of shi(H)S.5.3 Result of X3: Crowd A is in shi(H)P,the 49th grade;the Crowd N and Crowd C are in shi(H)S,the 15th grade.5.4 Result of X4: Crowd A and Crowd N are in shi(H)P,the 47th grade; Crowd C is in shi(H)S,the 7th grade.5.5 Result of X5: Crowd A and Crowd N are in shi(H)P,the 43th grade; Crowd C is in shi(H)S,the 15th grade.5.6 Result of X6:Three crowd are all in the second grade of shi(H)P.5.7 Result of X7: Crowd A is in the third grade of shi(H)P,while the other are in third grade of shi(H)S.5.8 Result of X8: Crowd A and Crowd N are all in the shi(H)P, the 47th an the 46th grade,while the Crowd C is in the shi(H)S,the 1st grade.5.9 Result of X9: Crowd A is in shi(H)P,the 49th grade;the Crowd N is in shi(H)S,the 19th grade, Crowd C are in shi(H)S,the 15th grade.5.10 Result of X10: Crowd A is in the tired grade of shi(H)P, Crowd N is in the forth grade of shi(H)S, Crowd C is in the third grade of shi(H)S.5.11 Result of X11: Crowd A is in the tired grade of shi(H)P,Crowd N is in the forth grade of shi(H)P, Crowd C is in the third grade of shi(H)S.5.12 Result of X12: Crowd A and Crowd N are all in the forth grade of shi(H)S, Crowd C is in the third grade of shi(H)S.5.13 Result of X13:Three crowd are all in the second grade of shi(H)P.5.14 Result of X14: Crowd A is in the second grade of shi(H)P,Crowd N is in the second grade of shi(H)S,Crowd C is in the third grade of shi(H)S.5.15 Result of X15: Crowd A is in the forth grade of shi(H)P,Crowd N is in the forth grade of shi(H)S,Crowd C is in the third grade of shi(H)S.5.16 Result of X16: Crowd A is in the shi(H)P,th 49th grade; Crowd N is in the shi(H)S,the 15th grade;Crowd C is in the shi(H)S,the 1st grade.5.17 Result of X17: Crowd A and Crowd N are in the shi(H)S,the 1st grade; Crowd C is in the shi(H)S,the 15th grade.Conclusions:1 The validity, reliability and acceptability of the questionnaires used in the investigation are good. The questionnaires can satisfy the requirements of the study.2 Q-type cluster analysis divided all the samples into 3 crowds. Eath crowd has its own characteristic. They can be named as the assentient crowd(Crowd A), the neutral crowd(Crowd N) and the conservative crowd(Crowd C).3 Though the cumulative logit regressionanalysis, the factors that affected the students premarital sexual attitude can be selected. According to the effedt from powerful to infirm, the influencing factors are ranked as: whether deen love would influnce study(X9), whether content to the study and living envirment(X8), the attirude to the traditional chastity concept(X16), how many course are don't qulified(X7), the family income (X3), mother'literary level(X5), the attitude to the sexual liberation(X15), whether the member of the Communist Party (X2), gender(X1), father'literary level(X4), how feel the study(X6), parents' attitude in fall in love (X12), whether parents' upbringing is scathing(X11).4 The set pair analysis can exquisitely express the uncertainty of each factor in different crowd. So rational advice can be provided to the heslth sex education. The facors, whether deen love would influnce study(X9), the attirude to the traditional chastity concept(X16), the attitude to the sexual liberation(X15), are fairly affect the students'sex attitude, forthermore the uncertainty of these factors is considerable, so the attitude may be changed by the education which aimed directly at these factors. The universitry should keep in touch with the parents, and to educate the students together. Forthermore the university can organize various kinds of activities to enrich the students'life. Besides improve the study and living envirment, supervise and to urge the students to work hard, enhance the education in political thought, all help to improve the students'premarial sexsual attitude.