《卫生统计学》ppt课件

《《卫生统计学》ppt课件》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、卫生统计学HealthStatistics第九章检验chi-squaretestVocabularyofchapter9Chi-squaretest卡方检验Statistics统计学Statistic统计量Statistician统计学家Populationrate总体率Samplerate样本率Pooledrate合并率Samplesize样本含量Samplingerror抽样误差Hypothesistesting假设检验Nullhypothesis无效假设（零假设）Vocabularyofchapter9Alternativehypothesis

2、备择假设Significancelevel检验水准Tableofcriticalvalue界值表PvalueP值Fourfoldtable，2×2table四格表Actual(observed)frequency实际(观察)频数Theoretical(expected)frequency理论(期望)频数Rowtotal行合计Columntotal列合计Association关联Independence独立Vocabularyofchapter9Categoricalvariable分类变量Distribution分布Goodnessoffittest

3、拟合优度检验Generalformula基本公式Specificformula专用公式Continuitycorrection连续性校正用途检验是定性资料统计推断的重要方法。两个或两个以上总体率或构成比的比较Comparisonoftwoormoreratesorproportions两个分类变量关联性检验Associationtestoftwocategoricalvariables频数分布的拟合优度检验GoodnessoffittestaboutfrequencydistributionsBasicthinkingofchi-squaretest

4、两种注射方式接种疫苗不良反应发生率分组有不良反应无不良反应合计反应率（％）肌内357410932.11皮下22719323.66合计5714520228.22四格表（fourfoldtable，2×2table）实际频数(actualfrequency,A)行合计(rowtotal,nR)列合计(columntotal,nC)总例数(n)Basicthinkingofchi-squaretestQuestion1：IfH0istrue,howmuchisthepointestimationofthepopulationresponserate?Que

5、stion2：IfH0istrue,howabouttherelationshipbetweenAandTinquantity?IfH0istrue,AandTshouldbecloseeachother.AT肌内：109×32.11％=35109×28.22％=30.76皮下：93×23.66％=2293×28.22％=26.24Basicthinkingofchi-squaretestQuestion3：HowtomeasurethedifferencebetweenAandTinquantity?DoesA-Twork?ATA-T3530.76

6、35-30.76=4.247478.2474-78.24=-4.242226.2422-26.24=-4.247166.7671-66.76=4.24×Basicthinkingofchi-squaretestQuestion3：HowtomeasurethedifferencebetweenAandTinquantity?Does(A-T)2work?ATA-T(A-T)220182424-24Does(A-T)2/Twork?ATA-T(A-T)2(A-T)2/T2018240.2224-241.00√×Basicthinkingofchi-sq

7、uaretest值反映了实际频数A与理论频数T的相对吻合程度。若检验假设H0成立，A与T应该比较接近，会小。若检验假设H0不成立，A与T相差较大，会大。如果得到一个较大的值，应怀疑H0的成立。Basicthinkingofchi-squaretest值除取决于A与T的吻合程度，还与格子数有关。格子数越多，值会越大。IfH0istrue,chi-squarestatisticwilltendtobesmall.IfH0isnottrue,chi-squarestatisticwilltendtobelarge.If,thenrejectH0。Other

8、wise,noreasontorejectH0。查界值表，得0.05＜P＜0.10，按α＝0.05水准，不拒