Spatial distribution of Parkinson's disease mortality in Spain, 1989-1998, as a guide for focused aetiological research or health-care intervention
1 Department of Applied Epidemiology, National Centre for Epidemiology, and Consortium for Biomedical Research in Neurodegenerative Diseases (Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas - CIBERNED), Carlos III Institute of Health. C/ Sinesio Delgado 6. 28029 Madrid. Spain
2 Environmental Health Group, Consortium for Biomedical Research in Epidemiology & Public Health-Carlos III Institute of Health (CIBERESP-ISCIII), Barcelona, Spain
3 Department of Pharmacology and Toxicology, Barcelona Institute of Biomedical Research (Instituto de Investigaciones Biomédicas de Barcelona -IIBB), Scientific Research Board-August Píi Sunyer Biomedical Research Institute (Consejo Superior de Investigaciones Científicas-Institut d'Investigacions Biomèdiques August Píi Sunyer:CSIC-IDIBAPS), Rosellón 161, E-08036 Barcelona, Spain
4 Environmental and Cancer Epidemiology Unit, National Centre for Epidemiology, Carlos III Institute of Health, C/ Sinesio Delgado 6. 28029, Madrid, Spain
5 Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP), C/ Sinesio Delgado 6. 28029, Madrid, Spain
BMC Public Health 2009, 9:445 doi:10.1186/1471-2458-9-445Published: 2 December 2009
Aetiologically, genetic and environmental factors having an uneven spatial distribution may underlie Parkinson's disease (PD). Undiagnosis of PD in selected regions might have limited access to treatment with levodopa and simultaneously, if present at death, determined PD underreporting at the death record. The purpose of this study was to describe and analyse municipal mortality due to PD in Spain in aetiological and interventional perspective.
PD mortality at a municipal level was modelled using the Besag-York- Molliè autoregressive spatial model, combining demographic information with cause-of-death diagnostic data (International Classification of Diseases 9th Revision (ICD-9) code 332.0). Municipal relative risks (RRs) were independently estimated for women, men and both sexes, and plotted on maps depicting smoothed RR estimates and the distribution of the posterior probability of RR>1.
A south-north gradient, with large geographical areas suggesting clustered towns with high mortality, was seen in Asturias, the Basque Country, Balearic Islands and, particularly, in the Lower Ebro valley around Tarragona. Similarly, there was a suggestion that lowest mortality was clustered in the south-east and south-west. We identified some isolated or clustered municipalities with high mortality that were situated near industrial plants reported to be associated with environmental xenobiotic emissions. However, the same pattern was also observed for some cities with low mortality.
Municipal PD mortality in Spain was unevenly distributed. Patterns were roughly similar to reported provincial PD mortality and use of levodopa. While the overall pattern appears to result from spatially selective PD undiagnosis, and can not be ascribed to industrial emissions, it can not be excluded that selected "hot spots" reflect genetic factors and/or environmental exposures inducing parkinsonism. A few municipal populations, located in low-mortality-risk areas in the vicinity of polluting plants or registering high excess PD mortality, might constitute a priority for conducting direct etiological studies. Additionally, interventions aimed to reduce potential PD undiagnosis might be most appropriate in the South.