Breslow-Day test 
A statistical test for the homogeneity of odds ratios.
 

Homogeneity

In  <javascript:void(0);> systematic reviews homogeneity refers to the
degree to which the results of studies included in a review are similar.
"Clinical homogeneity" means that, in studies included in a review, the
participants, interventions and outcome measures are similar or comparable.
Studies are considered "statistically homogeneous" if their results vary no
more than might be expected by the play of chance. See
<javascript:void(0);> heterogeneity.
 
 

Odds ratio (OR)

The ratio of the odds of an event in the experimental (intervention) group
to the odds of an event in the  <javascript:void(0);> control group. Odds
are the ratio of the number of people in a group with an event to the number
without an event. Thus, if a group of 100 people had an
<javascript:void(0);> event rate of 0.20, 20 people had the event and 80 did
not, and the odds would be 20/80 or 0.25. An odds ratio of one indicates no
difference between comparison groups. For undesirable outcomes an OR that is
less than one indicates that the intervention was effective in reducing the
risk of that outcome. When the event rate is small, odds ratios are very
similar to  <javascript:void(0);> relative risks.
 
 
http://www.cochrane.dk/cochrane/handbook/contents.htm
 
Bye,
Judit
 
 

	[[alternative HTML version deleted]]


