Bartlett's test for equal variances:
Comparison of ÖÎÁÆÇ° (bp0) by × ð(group) é± (Scheffe) Row MeanCol Mean low high -4.5 0.570 -5.75 0.413 -1.25 0.955 low
table
. table mods,c(mean ldh sd ldh p50 ldh) mods 0 1 mean(ldh) 282.473 892.15 sd(ldh) 210.1834 638.3892 med(ldh) 219 633
summarize
. sum(ldh),d ldh 1% 5% 10% 25% 50% 75% 90% 95% 99% Percentiles 29 131 146 186 265 460.5 1033 1402.3 2250 Largest 2036 2047.4 2250 2272 Smallest 2.9 29 115 117
signrank ranksum kwallis
. ranksum ldh,by(mods) Two-sample Wilcoxon rank-sum (Mann-Whitney) test mods 0 1 combined unadjusted variance adjustment for ties adjusted variance obs 85 28 113 22610.00 -1.13 22608.87 rank sum 3885 2556 6441 expected 4845 1596 6441
sktest sdtest
. sktest ldh Skewness/Kurtosis tests for Normality Variable ldh Obs 113 Pr(Skewness) 0.0000 Pr(Kurtosis) 0.0000 adj chi2(2) 52.62 joint Prob>chi2 0.0000
ratio = sd(0) / sd(1) Ho: ratio = 1 Ha: ratio < 1 Pr(F < f) = 0.0000 Ha: ratio != 1 2*Pr(F < f) = 0.0000
f = degrees of freedom =
Ha: ratio > 1 Pr(F > f) = 1.0000
diff = mean(0) - mean(1) Ho: diff = 0 Ha: diff < 0 Pr(T < t) = 0.0000
Ha: diff > 0 Pr(T > t) = 1.0000
ttesti
. ttesti 85 282.47 210.18 28 892.15 638.39 Two-sample t test with equal variances Obs x y combined diff 85 28 113 Mean 282.47 892.15 433.5412 -609.68 Std. Err. 22.79722 120.6444 42.20468 79.33417 Std. Dev. 210.18 638.39 448.6419 [95% Conf. Interval] 237.1352 644.6082 349.918 -766.8859 t = degrees of freedom = Ha: diff != 0 Pr(|T| > |t|) = 0.0000 327.8048 1139.692 517.1643 -452.4741 -7.6850 111
统计分析
统计描述
summarize describe table … graph twoway …
统计推断
ttest oneway anova ranksum kwallis tabi logit …
Stata
list
. l id 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 828966 769948 691896 679641 766834 746872 711428 699401 789971 788979 780270 775535 650668 697919 699401 sex 0 1 1 1 1 1 1 0 0 1 1 0 1 1 0 0 0 age 65 40 78 79 79 76 58 62 79 21 59 77 57 84 62 76 77 ldh 299.3 2036 881 2250 300 410 2047.4 633 225 1149 881 500 1248 345 633 460.5 359 cr 47.1 395.1 89.4 360.2 775 177 276 235.4 71 37 310 318 180 210 235 157 159 abl 34.4 25.9 39.1 26.2 22.4 21.1 27.1 24.7 30.2 21 34 28 29 32.7 24.7 26 35.4 mods 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 pre .0614 .99972 .17659 .99972 .99995 .86829 .99814 .93165 .1432 .85097 .92918 .94542 .92791 .51026 .93128 .69305 .23909
age 35 44 50 48 60 38 31 47 33 21 66 53
sex Male Female Female Male Male Male Female Female Female Female Male Female
bp0 139 148 139 148 135 150 144 150 151 151 153 142
diff = mean(x) - mean(y) Ho: diff = 0 Ha: diff < 0 Pr(T < t) = 0.0000
Ha: diff > 0 Pr(T > t) = 1.0000
ttest,une
. ttest ldh,by(mods) une Two-sample t test with unequal variances Group 0 1 combined diff Obs 85 28 113 Mean 282.4729 892.15 433.5434 -609.6771 Std. Err. 22.79759 120.6442 42.2047 122.7793 Std. Dev. 210.1834 638.3891 448.6421 [95% Conf. Interval] 237.1374 644.6085 349.9202 -860.8075 327.8085 1139.691 517.1666 -358.5467 -4.9656 28.9508
F
1.08
Prob > F
0.3794
Bartlett's test for equal variances:
Prob>chi2 = 0.808
oneway,sch
. oneway bp0 group,sch Analysis of Variance SS df MS 73.1666667 304.5 377.666667 2 9 11 36.5833333 33.8333333 34.3333333 chi2(2) = 0.4261 Prob>chi2 = 0.808 Source Between groups Within groups Total F 1.08 Prob > F 0.3794
LOGO
Stata在医学统计中的应用 在医学统计中的应用
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Contents
1 2 3 4 Stata概述 统计描述 统计推断 统计绘图
Stata概述 概述
统计学：挖掘数据背后的真理！ 统计学：挖掘数据背后的真理！ SAS 、Stata、 SPSS 、
Stata与统计学 与统计学
. sdtest ldh,by(mods) Variance ratio test Group 0 1 combined Obs 85 28 113 Mean 282.4729 892.15 433.5434 Std. Err. 22.79759 120.6442 42.2047 Std. Dev. 210.1834 638.3891 448.6421 [95% Conf. Interval] 237.1374 644.6085 349.9202 327.8085 1139.691 517.1666 0.1084 84, 27
Ho: ldh(mods==0) = ldh(mods==1) z = -6.385 Prob > |z| = 0.0000
oneway
. l
no 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 1 2 3 4 5 6 7 8 9 10 11 12
group placebo placebo placebo placebo low low low low high high high high
bp1
. oneway bp0 group
128 131 122 126ource
Between groups Within groups Total
Analysis of Variance SS df MS
73.1666667 304.5 377.666667 2 9 11 36.5833333 33.8333333 34.3333333 chi2(2) = 0.4261
Obs Sum of Wgt. Mean Std. Dev. Variance Skewness Kurtosis