epi.dsl {epiR} | R Documentation |
Computes individual study odds or risk ratios for binary outcome data. Computes the pooled odds or risk ratio using the DerSimonian and Laird method. Performs a test for the overall difference between groups.
epi.dsl(ev.trt, n.trt, ev.ctrl, n.ctrl, names, method = "odds.ratio", conf.level = 0.95)
ev.trt |
observed number of events in the treatment group. |
n.trt |
number in the treatment group. |
ev.ctrl |
observed number of events in the control group. |
n.ctrl |
number in the control group. |
names |
character string identifying each trial. |
method |
a character string indicating the method to be used. Options are odds.ratio or risk.ratio . |
conf.level |
magnitude of the returned confidence interval. Must be a single number between 0 and 1. |
A list containing the following:
odds.ratio |
the names of the trials specified, the odds ratios for each trial, the lower and upper bounds of the confidence interval of the odds ratio for each trial and the pooled odds ratio and the lower and upper bounds of the confidence interval of the pooled odds ratio. |
risk.ratio |
the names of the trials specified, the risk ratios for each trial, the lower and upper bounds of the confidence interval of the risk ratio for each trial and the pooled risk ratio and the lower and upper bounds of the confidence interval of the pooled risk ratio. |
weights |
the inverse variance and DerSimonian and Laird weights for each trial. |
heterogeneity |
a vector containing Q the heterogeneity test statistic, df the degrees of freedom and its associated P-value. |
Hsq |
the relative excess of the heterogeneity test statistic Q over the degrees of freedom df . |
Isq |
the percentage of total variation in study estimates that is due to heterogeneity rather than chance. |
tau.sq |
the variance of the treatment effect among trials. |
effect |
a vector containing z the test statistic for overall treatment effect and its associated P-value. |
Under the random-effects model, the assumption of a common treatment effect is relaxed, and the effect sizes are assumed to have a normal distribution with variance tau.sq
.
Using this method, the DerSimonian and Laird weights are used to compute the pooled odds ratio.
Deeks JJ, Altman DG, Bradburn MJ (2001). Statistical methods for examining heterogeneity and combining results from several studies in meta-analysis. In: Egger M, Davey Smith G, Altman D (eds). Systematic Review in Health Care Meta-Analysis in Context. British Medical Journal, London, 2001, pp. 291 - 299.
DerSimonian R, Laird N (1986). Meta-analysis in clinical trials. Controlled Clinical Trials 7: 177 - 188.
Higgins J, Thompson S (2002). Quantifying heterogeneity in a meta-analysis. Statistics in Medicine 21: 1539 - 1558.
data(epi.epidural) epi.dsl(ev.trt = epi.epidural$ev.trt, n.trt = epi.epidural$n.trt, ev.ctrl = epi.epidural$ev.ctrl, n.ctrl = epi.epidural$n.ctrl, names = as.character(epi.epidural$trial), method = "odds.ratio", conf.level = 0.05)