title: The spatial autocorrelation coefficient Moran's I under heteroscedasticity.
abstract: The spatial distribution of rates used in epidemiology often raises questions concerning the randomness of the observed pattern. In order to provide a first answer to this kind of question, the well-known spatial autocorrelation coefficient Moran's I is frequently used. Unfortunately, under heteroscedasticity, that is, unequal variances of the rates due to different population sizes, the moments of the test distribution of Moran's I under H(0) differ from the usually used moments. To obtain a less biased test, it is proposed in this paper and validated by simulation results, to approximate the moments of Moran's I by means of incorporating population size into the covariance matrix of the rates.
authors.affiliation: Department of Epidemiology, Institute of Tumor Biology & Cancer Research of the University of Vienna, Austria.
authors.forename: T
authors.initials: T
authors.lastname: Waldhör
mesh_terms: D000704:Analysis of Variance; D015982:Bias; D006801:Humans; D009010:Monte Carlo Method; D011156:Population Density; D015203:Reproducibility of Results; D012111:Residence Characteristics; D013029:Space-Time Clustering