???? ?????????? ??????? ????? ????

1
????? ????????? ??????? ????' ??? ???????? ?????
?' ???"?
2

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

3
???????????? -- ??? ???? ??? ????? ?????? ??????
?? ?????? ????? ????? ???? ??? ????? ???
????????? ????? ?????? ??? ?????? ??? ????? ??
????????? ???? ?? ?????? ?????? ????? ???????
?????
4
??? ????? ?????? ?????? ?? ?????? ????? ?????
???? ????? ??? ?????? ???????? ???????? 2001
?????? Journal of the National Cancer
Institute. ???? ?????? ?? ?????? ????? ????? ??
?? ?????? ???? ???? ???? ????? (risk factor).
???, ??? ??????? ??? ?????? ??? ????? ???????
???? ??? ???? ????? ????? ???.
5
????? ?????? ???? ?? ?????? ??????? ??? ????
78,562 ????? ???? 10 ????, ??? ?- 1988. ?????
????? ?? ????? ???? 42 ?? 67 ??? ???? ????? ???
?? ???? ???? ?????? ?????. ???? ?? ??? ??????
????? ???? ??? ?- 1976 ?? ???? ?- 120,000 ?????
(Nurses Health Study).
6
?????? ???? ????? ???? ?????? ????? ?????? ????
?? ??? ??????? ?? ??????. ?? ??? ??????? ??
??????? ?? ???? ??? ?????? ???? ?????? ???????
?????? ??? ????? ?? ??????. ?? ?? ??????? ??????
???????, ?????? ????? ?- 4 ?????? ????? ??????
??????? ???? ??? ??? ???? ???, ??? ????? 1 14
????, 15 29 ????, ?- 30 ???? ?????. ???????
???? ?? ?????? ?? ???? ??? ??? ????? ???????.
7
????? ???? ???? ?? Davis ??????? ??? ???? ?? 813
???? ??????? ?? ???? ??? ????? 2.5 ???? ??????
???? ?????? ?????? ?? 793 ???? ??????. ?????
??????? ?????? ????? ???? ??????, ??? ?????
???????? ???? ??? ????? ?????? ??????
???????. ???? ????? ???? ?? ?? ???? ?? ??????
????, ???? ????? ?????, ????? ????, ???'.
8

• ???? ????? ?? ?????? ?????
• ????? ?? ?????? ??? "???? ??????????"
  (prospective), ?? ?????? ????? ?? ??????, ???????
  ???? ??? ?????? ???????????, ??????? ?????? ???
  ?? ??? ????? ??? ??????? ???????????? ?????? ??
  ???? ????? ?????. ?? ???? ??????? ??? ??? ????
  "??????" (cohort study).
• ????? ?? ???? ?????????? ??? ?????? ????? ??
  ????? ????? ????? ?????. ???? ????? ?? ??????
  ??? ???? ????? ?? ?? ?????? ?? ?????? ???????
  ?????? ?? ???????.
• ????? ?? ???? ???? ??? ??? ????? ????? ?? ??
  ??????, ??????? ???? ????, ??? ????? ?????
  ??????? ?? ?????.

9

• ????? ?? Davis ??? ?????? ????? ????
  "????-??????" case-control study)). ????
  ????-?????? ????? ?? ????? ????? ?????? ???? ??
  ????? ?????? ?? ????? ??? ?????? ?? ?????.
• ??? ?? ???? ??? ?????? "???? ???????????"
  retrospective)) ????? ????????? ??? ?? ?????
  ????? ????, ????? ??? ??? ????? ???? (???? ??
  ????) ???? ????? ???. ?????? ?????????????
  ?????? ??? ?????, ????, ??? ????? ????? ?????
  (?????, ???? ??????, ???) ?? ??? ??????? ????
  ????? ???? ????? ????? ?? ?????? ??.

10

• ????? ???? ?? ???? ????-?????? ??? ??????? ??
  ????? ?????? ?????, ???? ?????? ????? ?? ????
  ???? ???? ???. ????? ????? ??? ????? ????? ???
  ????.
• ????? ???? ?? ???? ??????????? ??? ????? ????? ??
  ?????? ?? ??????? ???? ?????? ???? ?? ???????
  ????. ???? ??????? ????? ????-?????? ????? ???
  ?? ???? ?????? ?????? ??????. ?????? ??????
  ???????? ??????? ???. ???? ??? ???? ??? ????
  "??????" ?????? ?? ???? ?????? ???????.

11

• ??? ???? ????-??????, ???? "?????" ?? ?????? ??
  ????? ????? ??????. ?????? ????? ?? ?????
  ??????? ????? ??????, ???? ?? ??? ????? ??? ???
  ???? ??????. ??????? ?????, ???? ???? ???????
  ??????? ????? ????? ???????.
• ?? ????? ?????????? ????, ?????? ???????, ?????
  ??? ????? ????? ??? ??????. ?? ??????? ?????
  ???????? ????? ??????, ???? ??? ???? ????? ????
  ?? ??? ???? ??????? ???????. ?? ????? ?????
  ????? ???????.

12
????? ?? ?????? ??????
????? ????? ?- 1000 ???? ??? RR ???? RR ?????
?? ???? 925 3.10 1.00 1.00
1- 14 1324 3.45 1.11 1.12
15 29 134 3.29 1.06 1.08
30 - 58 4.62 1.49 1.54
13
RR ??? ????? ?- Relative Risk, ?????? ?????,
????? ?? ?????? ????? ?????? ????? ?????? ?????
?????? ????? ?????? ?????? (??? ??? ???? ??????
????). ?- RR ????? ????? ?? ??? ???? ?????? ?????
????? ????? ????? ????? ??????? ??????. ?- RR
?????? ???? ?????? ?????? ????? ??? ???????, ????
????? ??????? ?? ??????, ???? ?????, ????????
??????? ?? ???? ??? ????.
14
?????? ?? ????? ?? Davis ????? ?? ??? ?????? ????
??? ?? ?????? ?????.
????? ???? ?????? ???? ?????? ???? ????? ?????
????? 713 54 7.6
?????? 706 37 5.0
15
???? ????? ?????? ????? ??????, ???? ?? ????? ?-
OR ?? ??? ???? ?- 1.6. (OR Odds Ratio) ?????
????? ?????? ???? ????? ??? ?????? ???? ???? ????
????. ??????? ???? ???? ?????? ????? ?? ??? ????
??????? ?? ???? ????? ?? ???? ????.
16

• ?? ??? ?????? ?? ?"???" ??? ????? ??????? ?????
• ?????? ?????? ????? ???? ?????.
• ??? ???? ?????? ??????? ??? ???? "?????" ???
  ????? ?? ???? ??????? ??????? ????? ???, ???
  ????? ?? ??? ?????? ???? ?? ????? ?? ?? ??????.
• ??? ???? ?????? ?? ???? ????? ?????? (??? ????
  ???? ?? ????)? ???? ????, ?? ????? ??????, ?????
  ??? ??????? ???? ?????? ???? ???????? ?? ???????,
  ??? ????? ?????? ?????? ????? ?? ???????.

17
??? ????? ??? ????????? ????? ?????? ???
?????? ??????? ??????? ???? ?? ???? ??? ????
????? ?????? ????? ????????? ???? ???? ??????.
?? ?????? ??????? ?????? ????? ??? ????? ????"?
?? ?????? ??????. ???? ??? ????? ???????
???????. ???? ?? ??? ???? ??? (cross-sectional)
????? "?????" ?????? ??? ????? ?? ?????????. ??
??? ???? ????? ????, ???? ????? ??????? ?????
?????. ??? ??????? ??????? ???? ????? ?????? ???
????? ????? ?????, ??? ????? ?????????? ??????
????? ?????? ????? ???? ?? ????. ????? ????? ???
?? ????? ????? ??? ?????? ?????? ?????? ??? ????.
18

• ????? ????? ?????? ??? ??????? ?????
• ?????? ????? ???? ????? ?????.
• ????? ????????? ???? ???? ?????.
• ??? ??? ???? (Body Mass Index, BMI), ?????? ?????
  ??"? ???? ????? ????? ??"?.
• ???? ????, ????? ?? ??? ???? ?? ?????? ???
  (skinfolds).
• Journal of the American Medical Association,
  25/3/98

19

• ????? ???????
• 26 ?? ?????? ??? ??? 4 ???? ????, ??????, 35
  2-3 ????, ?- 39 ??? ?? ????, ??? ?????? ??????
  ??? ????-???? ?? ?????? ???.
• ????? ????? ??? ????? ???????? ???? ???? ??????.
• ?? ????? ????? ??? ?????? ?????? ????? ??????.

20
???? ??????? ?? ????? ?????? ??? ?????? ??????
????? (????) ???? BMI ???? Skin ???? BMI ???? Skin
1 20.1 21.4 19.7 25.8
2-3 21.2 23.8 20.0 27.0
4 20.6 24.4 21.3 30.2
21
??? ????? ?? ????????? ???? ?? ?????? ??????
????? ?? ??????? ????? ????? ?????? ?? ??????
???? ???? ?????? ??? ??????? ?????. ????? ?????
???? ????? ?????? ????? ???????? ???????. ?????
??? ?? ??????? ?? ????? ?? ????????? ??????.
22
??? ????? ?????? ????? ??????? (comparative
clinical trial). ??? ????? ????? ???????? ??????
?? ???? ??????. ?????? ??? ??????? ????? ????
???? ????? ?? ??? ???????? ???????. ???? ????
????? ?????? ????? ??? ???? ?? ?? ?????? ????
???? ????? ?? ?????? ??? ?????? ????????? ?? ???
??????? ??????? ??? ??????? ??????. ???????? ???
?????? ????? ???? ????? ????? ????? ????? ??
????? ???????.
23

• ????? ?? ????? ????? ??? ????? ?????? ???????
  ????? ???? ?? ??? ??????? ??????. ?? ??? ?????
  ???, ????? ????? ??? ?????? ?????? ??? ?????
  ????? ??? ????????. ????? ???????
• ????? ???????. ????, ??? ?????? ??????? ??????
  ?? ?????? ??????? ???????? ??? ????????.
• ????? ?????? ??????? ?????? (random allocation).
  ?????? ????? ??? ????? ??? ???? ????????? ????.
• Blinding. ????? ??? single blind ?? ???????? ??
  ?????? ???? ????? ?? ??????. ????? ??? double
  blind ?? ?? ??????? ?? ?????? ?? ???? ???? ?????.
  
• ??? ????? ????? (placebo), ????? ??? ??? ?????
  ????????.

24
????? ?? ????? ????? ??????? ???? ??? ????? ?????
???????. ????? ?????? ??????? (?? ?? ??? ?????
??????????) ????? ??????. ??? 491 ????? ??????
????? ?? ????????? ?- 485 ??? ?????. ???? ????
??????, ?? ???? ?????? ??? blinding. ??????? ????
???? ?????? ??? ????? ??????. ??????? ???? 3
???? ???? 50 ???? ??? ??? ????? ?? ?????????? ?-
55.5 ??? ??? ??? ?????. Lancet, 14/8/99
25
????? ?????? ???? ??????. ????? ????? ????
?????? ???? ?????????? ???? ??????????? ????
???
26
?? ???? ???????, ????? ?? ????? ?? ?????
????????? ?????? These cross-sectional studies
ask the question Do overweight children watch
more television than normal-weight children?
Cross-sectional studies cannot eliminate the
possibility that the causal arrow is backward.
Watching more television could be the consequence
of being overweight. For television viewing to
be a risk factor for childhood obesity,
precedence must be established -- a greater
amount of TV viewing must precede the development
of overweight. Precedence is not sufficient to
demonstrate causality. A causal relationship can
only be demonstrated in an experimental trial, in
which manipulation of the risk factor changes the
outcome. Given the need to identify causes of
childhood obesity, experimental studies are
needed.
27

• ??????? ??????

28

• "??? ?????? ????? ?? ?????" ???? ????, 1.12.00
• ??? ???? ???? ??? ???????? ?? ?? BRCA ???? ????
  ????
• ??? ???? ???? ?? ??? ???? ?????? ????? ????? ????
• ??? ?????? ?? ??????? ?? ????? ????????
• "?????? ?? ???? ???? ??????? ????? ??????. ..
  ??? ???? ????? ?? ??????? ??? ????? ????? ?????
  ?? ?????? ???? ??????? ???? ??????? ???? ?????
  ????? ?? ???? ????? ?????? ??????? ??? ????
  ?????."

29

• "?????? ????? ????? ????? ????? ?????" ????,
  13.2.01
• ??? ????? ?? ?????? ??? ????? ????? ?? ??????
  ???????
• ?? ??????? ?? ????? ?????? ??????? ??????? ?? ???
  ????? ?????
• ??? ????? ?? ?????? ?????? ????? ????? ???????
• ??? ????? ?? ?????? ????? ?????? ???????

30
"????? ????? ??? ???? ????? ???? ??????" ??????
???????, 5.3.01 ?? ??? ??"? ???? ???????? ?? ??
???'?? ???. ???? ????? ????? ?????? "?? ????
????." ???? ?- New England Journal of Medicine
????? 1997 ???? ?????? ???? ??? ??? ????? ?????
??? ???? ????? ??? ?????. ??? ???? ????? ???
????? ??? ???? ???? ???? ?????
31
??? ????? ?????? ?? ??????? ?? ????? ??? ???? ??
????? ??????? ??? ???? 72,488 ????? ???? 8 ????.
????? ????? ?? ????? ???? 40 ?? 65 ??? ???? ???
???? ?? ?? ?????. ?????? ????? ?? ???? ???? ??
????? ????? ????? ??????. ?? ?? ??????? ??????,
?????? ????? ?- 5 ?????? ????? ????? ?????, ????
??? ???? ??? ???? ????? ??????? ????? 3 ????
?????. New England Journal of Medicine, 26/8/99
32
???? 8 ???? ?? ????, ???? ????? ??? ??????
??????. ??????? ???? ?????? ??? ?????? ??
??????? ?? ????? ??. ?????? ????? ?? ??? ??????
??? ????? ???? ??????? ??????? ??? 2/3 ?? ??????
??? ???? ??? ????. ???? ????? 1. ??? ?????
????? "??????????" (prospective), ?? ?????? ?????
?? ??????, ??????? ???? ??? ?????? ???????????,
??????? ?????? ??? ?? ??? ????? ??? ???????
???????????? ?????? ?? ???? ????? ?????.
33
2. "???? ?????" ??? ??? ????? ?????? (ordinal).
?????? ????? ?????? ?? ??? ???? (???? ??? ??????
???? ??????? ??? ????) ??? ??? ????? ?????? ?????
??? ??????? ??? ???? ??????. ???? ????? ??????
????? ?????, ????? ?? ??????? ?- 0 ?? 4, ?? ?- 1
?? 5. ?????? ???????, ??????? ???? ?? ???????,
??? ?? ???? ??????. ????? ????? ?? ??????
?? ?????? ???????? (nominal) ??????? ??????? ???
??? ???, ??? ??? ?? ??? ?????. ?????? ???????
(numerical) ??? ??? ??, ???? ?? ???? ????.
34
3. ?????? ?? ????? ?? ????? ?? ??????? ????
?????? -- ???, ?????? ?????, ??? ??, ?????,
?????? ?????? ????. ??? ???? ????? ??????
???????? ??? ?????? ?????? ?? ????? ???? ??????
??????? ???? ????, ?????? ?????? ?? ??? ???? ??
??? ?? ???? ??????? ??????. ???, ??????? ??????
????? ????????? ?????? ??????? "?????" ??
????????? ????? ?? ?? ?????? ?????? ?? ?????.
35
??? ???? ???? ??? ???? ?????? ?? ?? ???????
???????? ???? ????? ???? ???????? ??? ?????,
????? ?????? ??????????? ????? ????? ?? ????????,
??? ???? ??? ????? ??????? ?? ????? ??????? --
???? ????? ?????? ?????? ?????? ??????? ???
????? ?????? ???? ???? ??????? ???? ??????? ???
?????? ????? ????. ???? ???? ?? ???? ????? ?????
?? ?? ?????? ??????? ???? ???? ???? ????? ??????.
36
????, ????? ?? ?????, ???? ?????? ?? ???? ??????
?? ?????. ??? ?? ???? ?? ????? ?? ???? ?? "???
?????" ?? ??? ??? ???? ?? ???? ???????? ???. ??
????? ???? ????, ???? ???? ??????. ????, ????
????? ???? ???? ?????? ???? ??? ?????? ????
?????? ??, ???? ?????? ?????? ???? ??? ??????
?????? ????? ?? ?????? ???? ??? ?? ????? ??????.
??? ?? ???? ?????? ??? ????? ?? ??????, ????
???????? "??????" ?? ?????? ?????? ???? ?? ???
?????? ?? ????? ?? ???????.
37
??? ????? ???? ?????? ????? ?????? ???? ????
?????? ????? ?? ???????? (venous
thrombosis)? ???? ????? ?????? ??? ?? ?? ?????
?????? ?? ?? ?????? ?????? ????? ???? ???????
??? ?? ???? ??? ????? ?? ???????? ???? ????? ??
????? ???????? ???? ?? ????? ????? -- folic acid
-- ???. ?? ???? ??? ????? ?? ????? ?????? ?????
?????? ??? ?????? ?????? ?? ???????? ???? ?????
?????? ?? ????? ??????. Arteriosclerosis and
Vascular Biology, 1999
38
???? ??? ???? "????-??????" (case-control study).
???? ????-?????? ????? ?? ????? ????? ??????
???? ?? ????? ?????? ?? ????? ??? ?????? ??
?????. ??? ?? ???? ??? ?????? "???? ???????????"
(retrospective) ????? ????????? ??? ?? ?????
????? ????, ????? ??? ??? ????? ???? (???? ??
????) ???? ????? ???. ?????? ?????????????
?????? ??? ?????, ????, ??? ????? ????? ?????
(?????, ???? ??????, ???) ?? ??? ??????? ????
????? ???? ????? ????? ?? ?????? ??.
39
?? ??????? ???? ????? ?????? ??? MTHFR C677T.
???? ???????
????? ???? ?????? ???? ????? ??? ???? ????? ???
???? VTE 162 37 22.8
?????? 336 48 14.3