?ppt?????????????????????

1
???????????? ?????
??? ??????????
2
????

• ?????????
• ????????
• ????????
• ????

?ppt?????????????????????????????,????????????
3
?????????

• ?????????
• ??????????
• ??????????
• ??/???????????
• ????????????

4
?????????(1)

• ???????????????????????????????
• ??????(??????????)
• ????????????????????????????????,??????????????
  ?????

5
?????????(2)

• ?????????????????????????????,???????(??,??)
• ???????????????????????????????????????
• ?????????????????????????

6
??????????

• ????????????
• ??????????????????????????
• Does exposure to aluminum cause Alzheimers
  dementia?
• Do statins cause cancer?

7
???????????
8
??????????
9
??/???????????

• ???? ????
• A 1 ???????????????
• ????????(?????)
• ????????
• B 2 ???????????
• ??????,??????RCT
• ????
• 3 ????-?????????
• ????-????
• C 4 ??????,??????????????
• D 5 ??????????????
• ???????????????

Oxford Centre for Evidence-based Medicine
Levels of Evidence(May 2001)
10
????????????

• ??????????
• RR(???) RCT, cohort study
• OR (???)case-control study
• NNH (number needed to harm)
• clinical importance
• ???????????1???
• ??1?????????????

11
?????(relative risk, RR)

• ??????????,?????????????????????,??????????????
• RRgt1 ??????(????)????????
• RRlt1 ??????(????)????????
• RR1 ???????????

12
???(odds ratio, OR)

• OR ??????,?????????????????????????
• ??(odds) ????????????????????

13
NNH

• Method for assessing clinical importance
• RCT or Cohort study, not case-control study
• Calculation to determine how many people must be
  exposed to the harmful agent to cause an adverse
  outcome
• the number needed to harm one more patients from
  the therapy
• ??1??????(???)???????(???)?????
• NNH 1 / ARI

14
??????????

• ?????????????,OR???RR,??????????OR??RR,????RR?,???
  ???
• RR ?OR??,?????????
• RR ?OR ???????,??????
• 1.2-1.5 ???
• 1.6-2.9 ????
• gt3.0 ???

15
????Confidence Interval

• ????????,?????
• ??????????????????
• 95?????
• ????
• ??????
• ????RR

16
?????????How to solve a clinical problem?
17
?????????

• ?????
• ???
• ?????
• ????
• ----
• ???????????
• ??

18
?????????

• ????????(EBCP)
• ????(ask a question)
• ????(acquire evidence)
• ????(appraise evidence)
• ????(apply evidence)
• ????(after assessment)

19
(No Transcript)
20
????(Clinical Scenario)

• 64???,????????1???????
• ????20?,?10?????,???????????????
• ????B????????,???????????3???????,?????????
  
• ????????,????3????????????,?????????????????
• ???,?????????????????????????????????????????????
  ????

21
????(Initial Question)

• ?????????????????
• ??????????????????

22
???????(Ask Clinical Questions)

• Initial question
• Framing the initial question answerable
• Patients (population)
• Intervention/exposure
• Comparison
• Outcome
• (PICO)
• ????,?????????,????

23
???????

• ?????????????????
• ??????????????????

24
????????????Framing the question

• ????(P) ?????
• ????(I) ??,??????
• ????(C)???,?????????
• ????(O) ???????,??

25
???????(Acquire Evidence)

• PICO key words
• Type of questionharm
• Best evidence
• Levels of evidence
• Optimal source of evidence
• Searching worthwhile?

26
???????

• ?????(optimal source)
• ??????????????????????
• ??????(search strategy)
• PICO??????
• ????(results)
• ?reference manager ??
• ?????????(screening)

27
???????Appraise Evidence

• ??????
• Are the results valid?
• ??????
• What are the results?

28
??????

• ????????
• Design
• Setting
• Participants
• Description of exposures
• Main outcome measures
• PICOS

29
??????Are the results valid?

• ???????????????????????????
• ????????????(?????)????????????????????
• ???????????????????????
• ???????????????????????
• ????(?????)???(?????)??????-????
• ????????????????????????
• ???????????????????????????????
• ???????????????????????

30
1. ?????????

• ???????
• ???????
• ???????????????

31
???

• Tripathi A, Folsom AR, Anderson KE. Risk factors
  for urinary bladder carcinoma in postmenopausal
  women.Cancer, 2002, 952316-2323
• ?????????????????,????1986???37459?55-69???,???199
  8?,?11??437516?????????69????(143232??),????????42
  ????(293284??)??????????5.49(?????)?2.10(?????)

32
???

• Pahor M, Guralnik JM, Ferrucci L, et al.
  Calcium-channel blockade and incidence of cancer
  in aged populations.Lancet, 1996,348 493-497
• ????????????????????,????????3???71?????????????,?
  ????????????????????????3.7?,??????????451???(1549
  ??)?,??47???,???????????????????????
  3.03?2.17,??????1.4?

33

• ???????????

34
2. ???????????????????

• ???????????????????????????????????????
• ????????????????????,????????????????
• ??????

35
3. ????????? ??????????????

• ????????????????,???????????????,?????????????,?
  ??????????????????????,???????????

36
4.?????????????

• ?????????????????????????????????,????????????
  ?????????????,????????????????????,????????
• ??,????????????????????,?????????????,???????????
  ??

37
5. ????(?????)??? (?????)??????-????

• ??,Doll?Hill????????????,??????,????????????????,?
  ?????????,???????????
• ??,????????????????????????????????????-????,?????
  ?????,??????????(RR)???(119?RR1.132039?RR5.
  47)?

38
6.????????????? ???????????

• ????????????????,????????,?????????????,??????????
  ????????,???????????????,???????????????

39
7.???????????????? ???????????????

• ??,???????????,??????7???????? ?30????-???????????
  ,?????????????????
• ?????????????????????,??????????????-????,???????,
  ???????????????????

40
8.??????????? ????????????

• ??,?????????,???????????????????????????????????
• ????????????????????,?????????????????????????????
  ?????????,???????????,??????????,?????????????,???
  ????????

41
??????????

• ???????????????8?????3?,????????????,?????????????
  ??,???????????????????????????????????????????
• ??????????
• ?????(RR)????(OR)?95????
• ????????????????

42
??????????
RR a(ab) c(cd)
43
??????????
????????????
??? ???? ? ?
???? ???? a b ab
????? ???? c d cd
? ? ac bd abcd
ORadbc
44
?????(RR)? ???(OR)?95????

• ???????????,???????????,?????RR?OR?95????,??95??
  ???????,?????????1.0,??????,???????

45
???????? ????????(NNH)

• ???????????????????,?
• ???????(RRI)(?????????????-??????????)??????????
  ???
• ???????(ARI)?????????????-??????????
• NNH1ARI

46
???????? ????????(NNH)

• ??????????????????????,?????????3.03,?????????2.1
  7,?
• ???????(RRI)(3.03-2.17)/3.03
• 28.38
• ???????(ARI) 3.03-2.170.86
• NNH1ARI1/0.86116
• ???116????????????1??????

47
???????How can I apply the results to my
patient?

• ???????????????????,??????????
• ?????????
• ????????????????????
• ????????????????????
• ?????????????????
• ??????????????????

48
???

• ???????
• ???????
• ????????