上海交大醫(yī)學(xué)院統(tǒng)計學(xué)上機(jī)重點

1、H0：不同組男女構(gòu)成比相等，1=2；H1：。統(tǒng)計結(jié)論，P>0.05,按=0.05水平不拒絕H0，無統(tǒng)計學(xué)差異，可認(rèn)為。相等。程序解釋：MEAN過程常用的主要統(tǒng)計量關(guān)鍵詞包括：N（樣本量）SUM（和）MEAN（均數(shù)） RANGE（全距） MIN（最小值） MAX（最大值） STD（標(biāo)準(zhǔn)差） CV（變異系數(shù)） VAR（方差） STDERR（標(biāo)準(zhǔn)誤） LCLM（總體均數(shù)可信區(qū)間下限） UCLM（上限） T（檢驗=0時的T值） PRT（t值對應(yīng)的雙側(cè)概率）data student;input sex $ age height weight birth yymmdd10.; index=weigh

2、t/height*2;cards;male 18 1.74 71.3 1981-3-21female 19 . 54.2 1982-12-4female 18 1.62 58.9 1981-5-6male 18 1.78 75.2 1980-1-4female 18 1.62 61.8 1981-7-12male 19 1.76 72.6 1981-9-23;proc print data=student;var sex age height weight index birth;format birth mmddyy10.;run;proc means data=student;var ag

3、e height weight index ;run;從已建立的SAS數(shù)據(jù)集中讀入數(shù)據(jù)建立新的SAS數(shù)據(jù)集libname course 'd:data'data course.student;set student;run;data a;set course.student;proc print;run;Data b;Set a;Run;數(shù)據(jù)集的拆分data male;set student;if sex='male' then output;run;data female;set student;if sex='male' then delet

4、e;run;data male female;set student;if sex='male' then output male;else output female;run;data height;set student;keep sex age height index;run;proc print ;run;data weight;set student;drop height birth;run;proc print ;run;多個SAS數(shù)據(jù)集縱向合并data one;input name $ pid group age;cards;Liming 111 1 54Wa

5、ngli 112 2 49Xiaoli 113 1 34;data two;input name $ pid drug $ sex;cards;Yaohong 211 A 1Zhaohong 212 B 2Mixue 213 A 2;data total;set one two;proc print data=one;proc print data=two;proc print data=total;run;多個SAS數(shù)據(jù)集橫向合并data one;input pid sex age;cards;101 1 54102 2 45103 2 42105 1 34;data two;input p

6、id weight height;cards;104 45 162102 64 171103 54 165101 51 160;proc sort data=one;by pid;proc sort data=two;by pid;data total;merge one two;by pid;proc print data=total;run;Means過程計算各統(tǒng)計量（std標(biāo)準(zhǔn)差）data shg;input x ;cards;108.0 97.6 103.4 101.6 104.4 98.5 110.5 103.8 109.7109.8104.5 99.5 104.0 103.9 97

7、.2 106.3 106.2 107.6 108.397.6102.7 103.7 107.6 103.2 103.6 103.3 102.8 102.3 102.2103.3101.2 107.5 106.3 109.7 99.5 107.4 103.4 106.6 105.7107.4103.0 109.6 106.4 107.3 100.6 112.3 100.5 101.9 98.899.7104.3 110.2 105.3 95.2 105.8 105.2 106.1 103.6 106.6105.1105.5 113.5 107.7 106.8 106.2 109.8 99.7 1

8、07.9 104.8103.9106.8 106.4 108.3 106.5 103.3 107.7 106.2 100.4 102.6102.1110.6 112.2 110.2 103.7 102.3 112.1 105.4 104.2 105.7104.4102.8 107.8 102.5 102.3 105.8 103.7 103.1 101.6 106.5100.0103.2 109.3 105.8 106.1 104.9 105.9 105.3 103.7 99.6106.2102.5 108.1 106.1 108.3 99.8 108.3 104.0 100.6 112.6 1

9、03.7;proc means data= shg n mean std cv min max;var x;run;分組計算各統(tǒng)計量“結(jié)果保留三位小數(shù)”data a; input group VA VB1;cards;1 1.8 1.4 2 1.7 1.1 1 2.2 1.5 3 1.9 1.2 2 2.5 1.0 1 2.7 1.6 2 2.3 1.3 2 2.8 0.9 3 3.0 1.1 1 2.6 1.4 1 2.4 1.2 2 1.9 1.3 3 2.9 0.8 1 3.2 1.7 3 3.1 1.5 2 2.6 1.9 3 3.5 1.6 3 3.3 1.5;proc sort d

10、ata=a ;by group;proc means mean std max min maxdec=3;by group;var VA VB1;run;計算幾何均數(shù)（頻數(shù)表）data a;input f x ;y=log10(x);cards;1 4 3 8 8 16 13 3221 64 9 128 4 256 1 512;proc means noprint;var y;freq f;output out=b mean=meany;run;data c;set b;meanx=10*(meany);run;proc print;run;程序解釋：FREQ<變量名>：規(guī)定該變量

11、的值為分析變量的頻數(shù)。OUTPUT<OUT=數(shù)據(jù)集名>：指定MEANS過程產(chǎn)生的統(tǒng)計量的輸出數(shù)據(jù)集名。統(tǒng)計量關(guān)鍵字=<新變量名列>···：指明在輸出數(shù)據(jù)集中想要的統(tǒng)計量，且指定這些統(tǒng)計量對應(yīng)的新變量名。univariate過程輸出3種數(shù)據(jù)圖（莖葉圖、盒式圖、正態(tài)概率圖），頻數(shù)表（變量值Value頻數(shù)Count百分?jǐn)?shù)Cell累計百分?jǐn)?shù)Cum），正態(tài)性檢驗結(jié)果data shg; input x ;cards;108.097.6103.4101.6104.498.5110.5103.8109.7109.8104.599.5104.0103.997

12、.2106.3106.2107.6108.397.6102.7103.7107.6103.2103.6103.3102.8102.3102.2103.3101.2107.5106.3109.799.5107.4103.4106.6105.7107.4103.0109.6106.4107.3100.6112.3100.5101.998.899.7104.3110.2105.395.2105.8105.2106.1103.6106.6105.1105.5113.5107.7106.8106.2109.899.7107.9104.8103.9106.8106.4108.3106.5103.3107.

13、7106.2100.4102.6102.1110.6112.2110.2103.7102.3112.1105.4104.2105.7104.4102.8107.8102.5102.3105.8103.7103.1101.6106.5100.0103.2109.3105.8106.1104.9105.9105.3103.799.6106.2102.5 108.1 106.1108.3 99.8 108.3 104.0 100.6 112.6103.7;proc univariate data=shg plot freq normal;var x;run;程序解釋：1、 Tests for Nor

14、mality為正態(tài)性檢驗，檢驗結(jié)果P>0.05，可認(rèn)為是正態(tài)分布。2、 Uncorrected SS為平方和；corrected SS為離均差平方和；Interquartile Range四分位數(shù)間距?？傮w均數(shù)的區(qū)間估計（計算總體均數(shù)的置信區(qū)間，99%的置信區(qū)間）data shg; input x ;cards;108.097.6103.4101.6104.498.5110.5103.8109.7109.8104.599.5104.0103.997.2106.3106.2107.6108.397.6102.7103.7107.6103.2103.6103.3102.8102.3102.2

15、103.3101.2107.5106.3109.799.5107.4103.4106.6105.7107.4103.0109.6106.4107.3100.6112.3100.5101.998.899.7104.3110.2105.395.2105.8105.2106.1103.6106.6105.1105.5113.5107.7106.8106.2109.899.7107.9104.8103.9106.8106.4108.3106.5103.3107.7106.2100.4102.6102.1110.6112.2110.2103.7102.3112.1105.4104.2105.7104.4

16、102.8107.8102.5102.3105.8103.7103.1101.6106.5100.0103.2109.3105.8106.1104.9105.9105.3103.799.6106.2102.5108.1 106.1108.3 99.8 108.3 104.0 100.6 112.6103.7;proc means data=shg n mean std clm alpha=0.01; var x;run;T檢驗：（1）樣本均數(shù)與總體均數(shù)比較的T檢驗（總體均數(shù)72 ；t（檢驗=0時的T值）; prt（t值對應(yīng)的雙側(cè)概率）data mb; input x ; d=x-72;card

17、s;74 73 68 75 75 82 80 69 72 74 83 72 71 74 76 79 67 73 81 70 67 70 78 69 70 72 67 74 80 66;proc means data=mb mean std stderr t prt;var x d;run;主要看d的t;prt也可以使用univariate過程proc univariate data=mb normal;var x d;run;（2） 配體設(shè)計樣本的T檢驗data ch4_7; input after before ; d=after-before;cards;70.5564.2988.6064

18、.0768.4445.8861.6445.2364.7350.4074.6861.5969.1551.8560.5160.1365.5964.2969.0451.93;proc means data=ch4_7 mean std stderr t prt; var d;run;（3） 成組設(shè)計兩樣本均數(shù)比較的t檢驗(ttest過程進(jìn)行成組t檢驗；class group表示分組變量為group；X為血紅蛋白的增加量)(3)-1data hb; input group x ; cards; 1 26 1 32 1 25 1 22 1 20 1 28 1 24 1 19 1 29 1 17 1 34

19、 1 21 1 20 1 23 1 27 2 21 2 23 2 18 2 24 2 23 2 19 2 16 2 22 2 20 2 25 2 23 2 17 2 15 2 26 2 22 ;proc ttest data=hb;class group;var x;run;結(jié)果解釋：先看方差齊性檢驗（Equality of Variances），P>0.05,方差齊；然后看t Value和對應(yīng)的P值，P<0.05,因此按=0.05水準(zhǔn)拒絕H0,故可認(rèn)為兩組貧血兒童的血紅蛋白的增加量不同，新藥組兒童的血紅蛋白增加量均數(shù)比常規(guī)藥組大。(3)-2:變量變換后成組比較的t檢驗（抗體滴度求

20、對數(shù)）data ktdd; input group x ; y=log10(x);cards;1 50 1 30 1 40 1 60 1 60 1 35 1 70 1 20 1 70 1 35 1 40 1 50 1 252 40 2 30 2 25 2 10 2 25 2 30 2 35 2 15 2 20 2 40 2 15 2 30 2 20;proc ttest; class group; var y;run;單因素三水平的方差分析1、 使用循環(huán)語句建立SAS數(shù)據(jù)集：（非常重要）data dat5_1; do group=1 to 3; input n; do i=1 to n; in

21、put x;output; end; end; cards; 15 40 10 35 25 20 15 35 15 -5 30 25 70 65 45 50 15 50 20 45 55 20 15 80 -10 105 75 10 60 45 60 30 10 60 30 100 85 20 55 45 30 77 105 ; run;2、 正態(tài)性檢驗：proc sort data=dat5_1;by group;run;proc univariate data=dat5_1 normal;var x;by group;run;3、 方差齊性檢驗：使用Levene檢驗，程序包含在glm和AN

22、OVA過程中。4、 方差分析：proc glm data=dat5_1;class group;model x=group;means group/hovtest;means group;run;結(jié)果解釋：1用glm過程進(jìn)行方差分析。2首先用class語句指定分組變量，此為group。3 然后用model語句指定所用模型。等號左邊為因變量，右邊為分組變量。4 MEANS關(guān)鍵詞后面是分組變量名，后面跟著一個斜杠，接著是這種選擇項。hovtest 做方差齊性檢驗（P>0.05方差齊）4、均數(shù)間的多重比較：proc glm data=dat5_1; class group; model x=g

23、roup; means group/hovtest; means group/snk bon dunnett('1'); means group/snk alpha=0.01; contrast '1 2 vs 3' group -0.5 -0.5 1; contrast '1 vs 2' group 1 -1 0; run;結(jié)果解釋：SAS中使用GLM過程步或ANOVA過程步中means語句后的選項來實現(xiàn)各種兩兩比較，程序中為幾種不同的比較方法。隨機(jī)區(qū)組設(shè)計方差分析：4個種系（區(qū)組）；3個處理data dat2; do block=1 to 4

24、; do treat=1 to 3; input x ; output; end; end;cards;76861151238854081103123357;proc glm data=dat2; class treat block; model x=treat block/p;output out=r R=RES; means treat block / snk; run; proc univariate data=r normal;var res;run;結(jié)果解釋：“/p”要求輸出預(yù)測值和殘差；output out將預(yù)測值和殘差輸?shù)綌?shù)據(jù)集r； RES為殘差的變量名；normal為對殘差進(jìn)行

25、正態(tài)性檢驗。拉丁方設(shè)計方差分析：data dat3; do person=1 to 5; do stress=1 to 5; input cloth $ x ; output; end; end;cards;B 103A 121C 100D 92 E 95C 102B 129D 98E 124 A 115D 118C 133E 103A 109 B 90E 99 D 122A 99 B 84 C 100A 102E 139B 103C 104 D 95;proc anova; class person stress cloth; model x=person stress cloth;run;

26、quit;相關(guān)分析：A藥在血中和尿中的半衰期：1、 建立數(shù)據(jù)集data dat1;input x1 x2;cards;9.9 7.911.28.99.4 8.58.4 9.414.81212.411.513.114.513.412.311.29.29.5 1110.78.39.2 8.5;run;2、繪制散點圖proc plot data=dat1;plot x1*x2='*'/haxis=by 3 vaxis=by 3;run;過程解釋：使用過程步plot進(jìn)行繪制散點圖。'*'定義散點的符號為*haxis vaxis說明間隔的距離*前為縱坐標(biāo)，后為橫坐標(biāo)。2、

27、 檢驗雙變量的二元正態(tài)分布proc reg data=dat1;model x2=x1/p;output out=r R=RES;run;proc univariate data=dat1 normal;var x1;run;proc univariate data=r normal;var res;run;過程解釋：Reg：做回歸方程估計，回歸分析Model 因變量=自變量/p對殘差和X1做正態(tài)性檢驗，若兩者的P值皆>0.05,表明符合二元正態(tài)分布。3、進(jìn)行相關(guān)分析proc corr data=dat1;var x1;with x2;run;過程解釋：使用過程步corr進(jìn)行相關(guān)分析。v

28、ar x1;with x2;指定欲分析的相關(guān)變量。0.72048是相關(guān)系數(shù)，0.0082是t檢驗的P值回歸分析：data dat2;input x y;cards;18.03314.97519.23727.83936.23;proc plot data=dat2;plot y*x='*'run;proc reg data=dat2;model y=x/p;plot y*x;run;intercept 截距為a(3.94300);3.46300為b四格表卡方檢驗：題：西藥治療79例，有效63人；中藥治療54例，有效47人，問兩種藥物治療有效率？data dat1; do r=1

29、to 2; do c=1 to 2; input freq ; output; end; end;cards;63 1647 7;run;proc freq data=dat1; tables r*c/chisq; weight freq;run;過程解釋：freq 頻數(shù)過程步用FREQ，TABLES語句定義列表的格式：行變量*列變量，斜杠后面是選擇項，chisq表示要卡方檢驗。Weight語句指定頻數(shù)變量。結(jié)果解釋： 4行分別代表頻數(shù)，總百分比，行百分比和列百分比proc freq data=dat1;tables r*c/chisq nopercent nocol expected; we

30、ight freq;run;過程解釋：nopercent nocol去掉總百分比和列百分比；expected計算每小格的理論頻數(shù)。K×2表卡方檢驗：題目：增加中西結(jié)合組68例，有效65，三種療法是否有差異？data dat2; do r=1 to 3; do c=1 to 2; input freq ; output; end; end;cards;63 1647 765 3;run;proc freq data=dat2; tables r*c/chisq nopercent nocol; weight freq;run;proc freq data=dat2; tables r*

31、c/chisq nopercent nocol exact; weight freq;run;過程解釋：這里沒有校正，如需進(jìn)行確切檢驗，可在TABLES語句后加上選擇項“exact”R×C表行列無序：data dat3; do r=1 to 3; do c=1 to 4; input freq ; output; end; end;cards;112 150 205 40200 112 135 73362 219 310 69;run;proc freq data=dat3; tables r*c/chisq nopercent nocol; weight freq;run;cmh輸

32、出結(jié)果，看，結(jié)果同上。proc freq data=dat3; tables r*c/noprint cmh; weight freq;run;R×C表行無序列有序：data dat4; do r=1 to 2; do c=1 to 3; input freq ; output; end; end;cards;13 10 621 7 4;proc freq data=dat4; tables r*c/nopct nocol chisq cmh; weight freq;run;過程解釋：TABLES語句后加入CMH選項，意在輸出CMH-卡方統(tǒng)計量的相關(guān)結(jié)果。結(jié)果解釋：看CMH卡方的輸

33、出結(jié)果，在行變量無序列變量有序的情況下，看中的Row Mean Scores DifferR×C表行有序列無序：data dat5; do r=1 to 3; do c=1 to 2; input freq ; output; end; end;cards;59 25169 29196 9;run;proc freq data=dat5; tables r*c/nopct nocol trend; weight freq;run;過程解釋：Trend為趨勢檢驗結(jié)果解釋：趨勢檢驗統(tǒng)計量Z和P，其中Z2=卡方。R×C表行列皆有序：data dat6; do r=1 to 4;

34、do c=1 to 4; input freq ; output; end; end;cards;4 11 143 4119 37 317 118339 22 182 355147 94 139 160;run;proc freq data=dat6; tables r*c/nopct nocol norow chisq cmh; weight freq;run;結(jié)果解釋：CMH中看Nonzero Correlation卡方檢驗看Mantel-Haenszel Chi-Square方表的一致性檢驗：data dat7; do r=1 to 2; do c=1 to 2; input freq

35、; output; end; end;cards;160 265 48;run;proc freq data=dat7; tables r*c/nopct nocol norow agree; weight freq;run;非參數(shù)統(tǒng)計：符號檢驗：data dat1; input a b; d=a-b;cards;1 01 01 00 11 01 01 01 01 0;proc univariate data=dat1; var d;run;結(jié)果解釋：看其中的Sign;表示符號統(tǒng)計量。符號秩和檢驗：data dat2; input before after; d=before-after;ca

36、rds;336 258371 291386 300364 285377 298292 303288 312304 260333 339302 290;proc univariate data=dat2 normal; var d;run;結(jié)果解釋：看其中的Signed Rank;表示符號秩和統(tǒng)計量（S）。兩獨立樣本秩和檢驗：data dat4; do group=1 to 2; input n; do i=1 to n; input x ; output; end; end;cards;80.32 0.47 0.57 2.21 0.64 3.08 0.67 2.13100.26 0.24 0.

37、59 0.37 0.58 0.21 0.33 0.42 0.67 0.45;run;proc univariate data=dat4 normal;class group;var x;run;proc npar1way data=dat4 wilcoxon; class group; var x;run;結(jié)果解釋：先正態(tài)性檢驗；然后看NPAR1WAY的運行結(jié)果。秩和（Sum of Scores）;平均秩和（Mean Score）。Statistic較小樣本的秩和；正態(tài)近似檢驗結(jié)果Z（=U），P雙側(cè)；同時還給出近似t檢驗和卡方檢驗的結(jié)果。多個獨立樣本秩和檢驗：data dat8; do group=1 to 3; inp