title: A rigorous small area modelling-study for the Helicobacter pylori epidemiology.
abstract: This paper presents an investigation into spatial risk differences over small distances for the Helicobacter pylori infection in the city of Leipzig, Germany and two rural districts. A model, using Bayesian inference, was developed that adjusts the risk for individual-specific factors, and for spatial or individual over-dispersion, respectively. Additionally, the model takes into account conditional spatial autocorrelation. We found a significant positive association to the H. pylori infection risk for: "more than three children live in the household" (OR=2.4, p=0.001), "more persons live per sq.m than average" (OR=1.4, p=0.03), "home situated at main road" (OR=1.4, p=0.04) and "using well water" (OR=2.3, p=0.05). A protective effect was identified for "travelled to low prevalence region" (OR=0.4, p<0.0001) and "born in Germany" (OR=0.2, p<0.0001). Three administrative areas with significantly increased spatial risk were identified: one in the rural district and two in the city of Leipzig. The model explained 24.9% of the total deviance. Contrary to expectations, the largest part of deviance of the data was not explained by the identified significant risk factors, but by individual-specific heterogeneities. We conclude that further - so far not discussed - factors influence the risk and the spatial variation of the H.pylori infection. Furthermore, from the results we speculate about a possible impact of long-time air pollution and surface water.
authors.affiliation: Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany. kathrin.strebel@ufz.de
authors.forename: Kathrin
authors.initials: K
authors.lastname: Strebel
authors.forename: Ulrike
authors.initials: U
authors.lastname: Rolle-Kampczyk
authors.forename: Matthias
authors.initials: M
authors.lastname: Richter
authors.forename: Annegret
authors.initials: A
authors.lastname: Kindler
authors.forename: Thomas
authors.initials: T
authors.lastname: Richter
authors.forename: Uwe
authors.initials: U
authors.lastname: Schlink
mesh_terms: D003710:Demography; D005260:Female; D005858:Germany / Q000453:epidemiology; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000635:transmission; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D018570:Risk Assessment; D012307:Risk Factors