Can you combine odds ratios?
You can combine those odds ratio if both studies consider the same outcome. The prevalence odds ratio (POR) is calculated in the same way as the odds ratio (OR).
How do you add odds ratios?
The odds ratio is calculated by dividing the odds of the first group by the odds in the second group. In the case of the worked example, it is the ratio of the odds of lung cancer in smokers divided by the odds of lung cancer in non-smokers: (647/622)/(2/27)=14.04.
How do you calculate combined odds?
Just multiply the probability of the first event by the second. For example, if the probability of event A is 2/9 and the probability of event B is 3/9 then the probability of both events happening at the same time is (2/9)*(3/9) = 6/81 = 2/27.
How to calculate the combined odds ratio between two variables?
I am using synergy factors to test synergy between two variables. The equation is simple enough, where O R 12 is the combined odds ratio for variables 1 and 2: How do I calculate the combined odds ratio for variables 1 and 2?
Where can I find the odds ratio calculator?
Pagano M, Gauvreau K (2000) Principles of biostatistics. 2nd ed. Belmont, CA: Brooks/Cole. Parshall MB (2013) Unpacking the 2 x 2 table. Heart & Lung 42:221-226. Sheskin DJ (2004) Handbook of parametric and nonparametric statistical procedures. 3 rd ed. Boca Raton: Chapman & Hall /CRC.
How is the odds ratio calculated in MedCalc?
The odds ratio is given by with the standard error of the log odds ratio being and 95% confidence interval Where zeros cause problems with computation of the odds ratio or its standard error, 0.5 is added to all cells (a, b, c, d) (Pagano & Gauvreau, 2000; Deeks & Higgins, 2010). Test of significance:…
How is the odds ratio of death calculated?
The odds ratio is simply the ratio between the following two ratios: The ratio between standard treatment and the new drug for those who died, and the ratio between standard treatment and the new drug for those who survived. From the data in the table 1, it is calculated as follows: OR = (a/b)/ (c/d) = (152/17)/.