has_specified_input random effect model meta analysis Sidik-Jonkman estimator meta analysis by Hartung-Knapp-Sidik-Jonkman method HKSJ method Philippe Rocca-Serra a random effect meta analysis procedure defined by Hartung and Knapp and by Sidik and Jonkman which performs better than DerSimonian and Laird approach, especially when there is heterogeneity and the number of studies in the meta-analysis is small. doi:10.1186/1471-2288-14-25 http://www.inside-r.org/packages/cran/meta/docs/metacor metacor(cor, n, studlab, data=NULL, subset=NULL, sm=.settings$smcor, level=.settings$level, level.comb=.settings$level.comb, comb.fixed=.settings$comb.fixed, comb.random=.settings$comb.random, hakn="TRUE", method.tau="HS", tau.common=.settings$tau.common, prediction=.settings$prediction, level.predict=.settings$level.predict, method.bias=.settings$method.bias, backtransf=.settings$backtransf, title=.settings$title, complab=.settings$complab, outclab="", byvar, bylab, print.byvar=.settings$print.byvar, keepdata=.settings$keepdata ) metadata incomplete