9. • The decimal point is 1 digit(s) to the right of the |
• 1 | 389
• 2 | 0227
• 3 | 044
• 4|
• 5|0
• The decimal point is 1 digit(s) to the right of the |
• 1 | 67
• 2 | 223333
• 3|
• 4|2
• $placebo
• NULL
• $drug
• NULL
• polyps_glm.1<-glm(number~treat+age, data=polyps, family=poisson())
• ## polyps_glm.1 에 glm함수(poisson) objecting
• summary(polyps_glm.1)
• ## glm, poisson 에러 모형으로 적합test
10. • Call:
• glm(formula = number ~ treat + age, family = poisson(), data = polyps)
• Deviance Residuals:
• Min 1Q Median 3Q Max
• -4.2212 -3.0536 -0.1802 1.4459 5.8301
• Coefficients:
• Estimate Std. Error z value Pr(>|z|)
• (Intercept) 4.529024 0.146872 30.84 < 2e-16 ***
• treatdrug -1.359083 0.117643 -11.55 < 2e-16 ***
• age -0.038830 0.005955 -6.52 7.02e-11 ***
• ---
• Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
• (Dispersion parameter for poisson family taken to be 1)
• Null deviance: 378.66 on 19 degrees of freedom
• Residual deviance: 179.54 on 17 degrees of freedom
• AIC: 273.88
• Number of Fisher Scoring iterations: 5
11. • polyps_glm.2<-glm(number~treat+age, data=polyps, family=quasipoisson())
• ## polyps_glm.2 에 glm 함수(quasipoisson) objecting
• summary(polyps_glm.2)
• ## glm, quasi-poisson 에러 모형으로 적합
• Call:
• glm(formula = number ~ treat + age, family = quasipoisson(),
• data = polyps)
• Deviance Residuals:
• Min 1Q Median 3Q Max
• -4.2212 -3.0536 -0.1802 1.4459 5.8301
• Coefficients:
• Estimate Std. Error t value Pr(>|t|)
• (Intercept) 4.52902 0.48106 9.415 3.72e-08 ***
• treatdrug -1.35908 0.38533 -3.527 0.00259 **
• age -0.03883 0.01951 -1.991 0.06284 .
• ---
• Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
• (Dispersion parameter for quasipoisson family taken to be 10.72805)
• Null deviance: 378.66 on 19 degrees of freedom
• Residual deviance: 179.54 on 17 degrees of freedom
• AIC: NA
• Number of Fisher Scoring iterations: 5
14. • Eicosanoids are synthesized from
arachidonic acid, which is formed from
phospholipids.
• Arachidonic acid is converted to
prostaglandin H2, catalyzed by
cyclooxygenase.
• This enzyme is the target of aspirin and
other nonsteroidal anti-inflammatory
drugs (NSAIDs).
15. • Aspirin and NSAIDs have also been found to
reduce the frequency of colon cancer, apparently
by inhibiting synthesis of prostaglandins that
stimulate cell proliferation
• Cox-1, cox-2 와 polyps, GI tract , asthma
• Vioxx, celebrex 의 항암작용
• Polyps와 NSAID의 실효성
16. 결과 정리 및 요약
• R을 이용한 통계자료 분석 결과
▫ Drug(NSAIDs)가 placebo와는 다르게 유의한 효과가 있다
▫ Age는 treatment에 아무런 연관이 없다
▫ Poisson과 quasi-poisson model의 차이는 polyps 발생 숫자의
overdispersion 에 의한 것이다
• 생화학적 사실에 근거한 분석 결과
▫ Prostaglandin 은 cell proliferation 을 activation 시켜
polyps, 또는 cancer를 발생시킨다
▫ NSAIDs는 archidonic acid로부터 prostaglandin 을 유도하는 효소;
Cyclooxigenase(COX) 를 저해한다
