European Journal of Epidemiology

, Volume 22, Issue 11, pp 781–790

Geographic distribution of amyotrophic lateral sclerosis through motor neuron disease mortality data

  • Raffaella Uccelli
  • Alessandra Binazzi
  • Pierluigi Altavista
  • Stefano Belli
  • Pietro Comba
  • Marina Mastrantonio
  • Nicola Vanacore
Neuro-Epidemiology

DOI: 10.1007/s10654-007-9173-7

Cite this article as:
Uccelli, R., Binazzi, A., Altavista, P. et al. Eur J Epidemiol (2007) 22: 781. doi:10.1007/s10654-007-9173-7

Abstract

Amyotrophic lateral sclerosis (ALS) is a rare and devastating neurological disorder of the adult age with a prognosis of about 2–3 years from the onset of the disease. No clear cause has been identified but it seems to be a multifactorial disease with genetic and environmental components involved. Increments of mortality rates were observed since 1980 both in Italy and in many other countries. The objective of the present study is to describe the distribution of ALS mortality in Italy in the period 1980–2001 detecting single municipalities or clusters with high mortality levels for motor neuron disease (MND). ALS represents the main part (85%) of the MND group which is globally identified by the IX ICD (International Classification of Diseases and Causes of Death) 335.2 code. Death numbers and standardized mortality ratios (SMR) for MND were calculated for all Italian municipalities through the ENEA mortality database system (data source: National Institute of Statistics—ISTAT), using national mortality rates as reference. Subsequently, in order to detect municipal clusters, spatial analysis was performed. Out of the 8,099 Italian municipalities, 132 where characterized by SMR values higher than expected. Moreover 16 clusters with significant high relative risk values (RR) were identified, 12 out of them including only a single municipality. Only 22 of the municipalities with high SMR were included in the clusters. In conclusion, the two different epidemiological methodologies demonstrated to be widely complementary in detecting the geographical distribution of the disease in terms of risk for populations. A first selection of the priority areas where analytical studies should be carried on, in order to identify risk factors associated to ALS, is tentatively suggested.

Keywords

Amyothrophic lateral sclerosisCluster analysisEnviromental epidemiologyGeographic distributionMortalityMotor neuron disease

Abbreviations

ALS

Amyotrophic lateral sclerosis

CI

Confidence Intervals

ICD

International Classification of Diseases

ISTAT

Italian National Institute of Statistics

ENEA

The National Agency for New Technologies, Energy and the Environment

LLR

Log likelihood ratio

MND

Motor neuron disease

OU

Observational unit

SMR

Standardized mortality ratio

RR

Relative risk

s.s.

Statistically significant

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  • Raffaella Uccelli
    • 1
  • Alessandra Binazzi
    • 2
  • Pierluigi Altavista
    • 1
  • Stefano Belli
    • 3
  • Pietro Comba
    • 3
  • Marina Mastrantonio
    • 1
  • Nicola Vanacore
    • 4
  1. 1.Section of Toxicology and Biomedical SciencesNational Agency for New Technologies, Energy and the Environment (ENEA)RomeItaly
  2. 2.Epidemiology Unit, Occupational Medicine DepartmentNational Institute for Occupational Safety and Prevention (ISPESL)RomeItaly
  3. 3.Department of Environment and Primary Prevention (DACPP)Istituto Superiore di Sanità (ISS)RomeItaly
  4. 4.National Centre for Epidemiology, Surveillance and Health Promotion (CNESPS)Istituto Superiore di Sanità (ISS)RomeItaly