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.

24

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.

, - .1 , ( , , -), -, .2 ,, (evidence-based medicine),3 , , , . -, - , , .

; , ; ; -, , - . British Medical Journal , , , Internet (www.bmj.com).

( ). 4 -, 1993, , , , - , , . , - 19501997 - , , - -. , , , 1960 .

.5 , , . -, , . (randomizedcontrolled trial, RCT) - .6

7 (. 1). , -

EDITORIAL

17(5), 2000 441

, , -, -, (.., , ), , , . , - , - - , -. , , .8 -, -. , , -:

, - ;

19501997;

, ;

, , , , .

, , , -. , - Murlow,9 , , :

. (gen-eralisability), (consistency) (inconsistency) . , - - , 4 .6 , -, . , 4 (trend) , , (. 2). , , -, .5

. (power) (precision) - (effect).

1 . .

2 . . -.*

1 155/1906 187/1900 0,81 (0,651,01) 2 56/2051 84/2030 0,65 (0,460,92) 3 174/3302 248/3293 0,68 (0,560,83) 4 56/3304 96/3301 0,58 (0,410,80) 441/10563 615/10524 0,70 (0,620,79)

* Pignone et al. Br Med J 2000, 321:15. :

( / ) ( / ) ( 9 5 % )

(as-sociation), .10 . , ( ) .11 2, - -,6 , , 1906 - , 155 ( 81,3 1000). , 187 1900 ( 98,4 1000). 3800 , 17,1 1000 . , , - 43%!12

, 6.500 , 80%. , ( ), - , , (chance). , - ( ' ) , , 20.000 , .

- , -, (precision) . , 95% . - , , - , . , - - (point es-timate) - (odds ratio) -. 95% - , ,

, (true value) (-, 2, 0,46 0,92 0,620,79).

- (. 1). , ' - . . (biases), (selection bias).

, -.13 - (association) . , , (random error) (confounding), . ' , - . - -. , , - .

, - . (reference population), , - , ,

442 ARCHIVES OF HELLENIC MEDICINE 17(5), 2000

. , , - . -, , - ( ) (eligible population).

(. 3). , - - -. - ., . - , , (publication/citationbias).14 , .15 , . , - -. - !

, ; . , , .

, -.16 () , .. MedLine, Em-base, Cinahl, Psychinfo, Current Contents, () , - - ( 100%). - ' ,() - , , , , , () , () - , () , on-line Cochrane(Cochrane Collaboration), () , .. (gray literature).

, . , . -, - .( : , - ). , , :4 () 19801996 19791996 , () 19501997,

17(5), 2000 443

3 . .

1. (source population) 2.

(eligible population)

19751997 , () -, () , , 19701995, () 19601995. ( , !). , . .., , , - .

, . - (inclusion-exclusion), , . , , . , -, - - , , , :5 () , 65 , . , - . () , , (blind). () ,

, , , .., - , , , , .., , - (falls) . , . , - 244 . , 29 15 .

(data extraction) .7 -, , , , , - , -, , , , , , .. , - , -, , . (heterogeneity) .17 ( ), ( ) ( ). -, , .18

, -. -, : () - , .

444 ARCHIVES OF HELLENIC MEDICINE 17(5), 2000

17(5), 2000 445

, , , - , , . () - , . () - , , , x2 . ' , (weight-ed average) .

. -, , . . . . , , - - . ,, . , , .18 , ,19 , , , , -, - , - .

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