title: Level-adjusted funnel plots based on predicted marginal expectations: an application to prophylactic antibiotics in gallstone surgery.
abstract: Funnel plots are widely used to visualize grouped data, for example, in institutional comparison. This paper extends the concept to a multi-level setting, displaying one level at a time, adjusted for the other levels, as well as for covariates at all levels. These level-adjusted funnel plots are based on a Markov chain Monte Carlo fit of a random effects model, translating the estimated model parameters to predicted marginal expectations. Working within the estimation framework, we accommodate outlying institutions using heavy-tailed random effects distributions. We also develop computer-efficient methods to compute predicted probabilities in the case of dichotomous outcome data and various random effect distributions. We apply the method to a data set on prophylactic antibiotics in gallstone surgery.
authors: Uppsala Clinical Research Center, Uppsala, Sweden.
authors: Lars
authors: L
authors: Lindhagen
authors: Bahman
authors: B
authors: Darkahi
authors: Gabriel
authors: G
authors: Sandblom
authors: Lars
authors: L
authors: Berglund
mesh_terms: D019072:Antibiotic Prophylaxis; D002763:Cholecystectomy; D016000:Cluster Analysis; D003627:Data Interpretation, Statistical; D042882:Gallstones / Q000601:surgery; D006801:Humans; D008390:Markov Chains; D015233:Models, Statistical; D009010:Monte Carlo Method
keywords: Markov chain Monte Carlo; funnel plot; level adjustment; predicted marginal expectation; random effects model