Detailed analysis methods are described in our previously published metaanalysis 20. Using risk difference as opposed to oddsratio in metaanalysis. Metaanalysis may be used to investigate the combination or interaction of a group of. What if you would prefer to work with the risk ratio. Smds of all five trials were pooled in a random effects metaanalysis to give a. Metaanalysis of studies with binary relative risk, odds ratio, risk difference. What is the difference between metaanalysis, systemic. Other methods are available to convert smd directly to risk difference and. Appropriate and accessible statistical software is needed to produce the. This choice of weights minimizes the imprecision uncertainty of the pooled effect estimate. Briefly, we used the standardized mean difference smd between the. Most metaanalytical software routines including those in revman. Outcomes from a metaanalysis may include a more precise estimate of the effect of treatment or risk factor for disease, or other outcomes, than any individual study contributing to the pooled.
A confidence interval for the pooled risk difference is calculated using the. Note that the results from statsdirect may differ slightly from other software or. The effect of istradefylline for parkinsons disease. Metaanalysis methods for combining risk differences based on a varying coefficient model 5 do not require the population risk differences to be identical across studies nor do they assume that. The objective of this study was to investigate the associations between selenium exposure and cancer risk. Results for log risk ratio see table vii in hartung and knapp 2001.
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