Meta-análisis - Web de Ferran Torres

Study
ANDERSON 1988
BELL 1989
BELL 1990
LEVIN 1990
NEAL 1990
ANDERSON 1991
ANDERSON 1992
EVERSON 1992
SPRECHER 1993
SPRECHERON 1993
MACIEJKO 1994
WILLIAMS 1995
WEINGAND 1997
RODRIGUEZ-MORAN 1998
ANDERSON 1999
Fiber vs Placebo effect in lipid reduction. Triglycerides
Difference of means (mmol/L), Random effects
Fiber
n: mean(SD)
13: -0.210(0.058)
40: 0.030(0.302)
19: -0.135(0.214)
30: -0.011(0.320)
27: -0.240(0.293)
27: 0.200(0.516)
21: 0.080(0.455)
20: 0.102(0.630)
59: 0.006(0.308)
20: 0.240(0.805)
18: 0.450(1.008)
26: -0.142(0.249)
23: 0.002(0.781)
62: -0.554(0.781)
14: 0.165(0.781)
Control
n: mean(SD)
13: 0.190(0.479)
35: -0.050(0.102)
19: 0.030(0.201)
28: 0.000(0.088)
27: -0.140(0.313)
25: -0.120(0.185)
23: 0.300(0.791)
20: 0.000(0.224)
59: 0.150(0.345)
20: 0.920(1.163)
18: 0.410(0.351)
24: -0.232(0.137)
23: 0.002(0.781)
63: -0.181(0.781)
15: 0.342(0.781)
Estimates with 95% confidence intervals
Subgroups
SS with ES>1
– Cholesterol and LDL
fiber food supplement compound
intake duration between 4 and 8 weeks
daily doses >10G/d
Moderate SS ES
– >8 weeks regimens
-0.7 cholesterol and -0.8 LDL
SS with ES≈1
– periods of study publication: no clear trend
Pooled(random effects)
n=412
n=419
-0.07 ( -0.16 , 0.03 )
-1.0 -0.7 -0.4 -0.1 0.1 0.3 0.5 0.7 0.9
Absolute Baseline Reduction
Adult population: replication of the main pooled
effect because only 2 studies on childhood.
Fiber better
Control better
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2007 Ferran.Torres@uab.es 62
Group
Cholesterol
Hedges’ g
estimator
(random)
95%
Lower
Limit
95%
Upper
Limit
P value
Main pooled effect 0.000 -1.007 -1.311 -0.703
Type of fiber
Fiber food supplement compound 0.000 -1.134 -1.561 -0.707
Diet or Cereals supplements 0.000 -0.869 -1.313 -0.426
Duration of fiber Intake
4 to 8 weeks 0.024 -0.672 -1.255 -0.088
Daily dose
< 5 G/d 0.939 -0.024 -0.644 0.596
>= 5 to 10 G/d 0.005 -0.908 -1.542 -0.275
>10 G/d 0.000 -1.123 -1.477 -0.769
Population
Non Adults 0.303 -0.786 -2.282 0.711
Adults 0.000 -1.032 -1.350 -0.714
Year of publication
1988-1990 0.000 -1.807 -2.418 -1.196
1991-1993 0.001 -0.786 -1.234 -0.338
1994-1997 0.000 -0.971 -1.456 -0.486
>=1998 0.016 -0.370 -0.673 -0.068
Group
LDL
Hedges’ g
estimator
(random)
95%
Lower
Limit
95%
Upper
Limit
P value
Main pooled effect 0.000 -1.023 -1.356 -0.690
Type of fiber
Fiber food supplement compound 0.000 -1.191 -1.569 -0.813
Diet or Cereals supplements 0.002 -0.833 -1.360 -0.306
Duration of fiber Intake
4 to 8 weeks 0.036 -0.765 -1.480 -0.051
Daily dose
< 5 G/d 0.389 0.274 -0.349 0.897
>= 5 to 10 G/d 0.022 -0.950 -1.761 -0.139
>10 G/d 0.000 -1.154 -1.457 -0.851
Population
Non Adults 0.441 -0.942 -3.338 1.454
Adults 0.000 -1.029 -1.354 -0.704
Year of publication
1988-1990 0.001 -1.192 -1.891 -0.493
1991-1993 0.003 -1.102 -1.834 -0.370
1994-1997 0.001 -1.245 -2.008 -0.481
>=1998 0.008 -0.453 -0.788 -0.118
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2007 Ferran.Torres@uab.es 64
Meta-an
análisis
Ejemplo
Ferran Torres
Ferran.Torres@uab.es
Example
Fleiss JL The statistical basis of meta-analysis.
analysis.
Statistical Methods in Medical research 1993; 2:
121-145.
145.
Results of seven placebo-controlled controlled randomised
studies of the effect of aspirin in preventing
death after myocardial infarction
2007 Ferran.Torres@uab.es 65
2007 Ferran.Torres@uab.es 66
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