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We aimed to assess whether rural residence is associated with amyotrophic lateral sclerosis in the south-east of England using a population based register. Previous studies in different populations have produced contradictory findings. Residence defined by London borough or non-metropolitan district at time of diagnosis was recorded for each incident case in the South-East England ALS Register between 1995 and 2005. Each of the 26 boroughs or districts of the catchment area of the register was classified according to population density. Age- and sex-adjusted incidence of ALS was calculated for each region and the relationship with population density tested by linear regression, thereby controlling for the underlying population structure. We found that population density in region of residence at diagnosis explained 25% of the variance in ALS rates ( r = 0.5, p < 0.01). Thus, in this cohort in the south-east of England, people with ALS were more likely to be resident in areas of high population density at diagnosis. [ABSTRACT FROM AUTHOR]

Previous studies have suggested a lower incidence of ALS in people of African origin. We used a population based register in an urban setting from inner city London postcodes where there is a large population of people of African ancestry to compare the frequency of ALS in people of European and African origin. Population statistics stratified by age, gender and ethnicity were obtained from the 2001 census. Incidence and prevalence were calculated in each ethnic group. Results showed that in a population of 683,194, of which 22% were of African ancestry, 88 individuals with ALS were identified over a seven-year period, including 14 people with African ancestry. The adjusted incidence in people of African ancestry was 1.35 per 100,000 person-years (95% CI 0.72-2.3) and in those of European ancestry 1.97 per 100,000 person-years (95% CI 1.55-2.48). In conclusion, in this small population based study we could not detect a difference in rates of ALS between people of African ancestry and those of European ancestry. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS, motor neuron disease) is a neurodegenerative disorder of motor neurons leading to paralysis and eventual death by respiratory failure. Median survival is 2-3 years. Susceptibility genes, environmental triggers and disease related prognostic factors have been established, but environmental effects on survival are yet to be investigated. We analysed survival in the South-East England ALS register (SEALS register). Kaplan-Meier and Cox regression analyses were used to investigate survival in London, coastal and rural areas according to postcode at diagnosis. Results showed that there were 933 cases of ALS identified in the catchment area during the study period (1994-January 2012). Cox regression demonstrated a highly significant model for survival with significant protective variables: coastal residency, riluzole use and younger age at onset. Significantly worse survival was associated with London residency, older age as well as definite and probable El Escorial classifications. In conclusion, these findings suggest the possibility of an environmental effect on survival in ALS.

Background: Amyotrophic lateral sclerosis shares characteristics with some cancers, such as onset being more common in later life, progression usually being rapid, the disease affecting a particular cell type, and showing complex inheritance. We used a model originally applied to cancer epidemiology to investigate the hypothesis that amyotrophic lateral sclerosis is a multistep process., Methods: We generated incidence data by age and sex from amyotrophic lateral sclerosis population registers in Ireland (registration dates 1995-2012), the Netherlands (2006-12), Italy (1995-2004), Scotland (1989-98), and England (2002-09), and calculated age and sex-adjusted incidences for each register. We regressed the log of age-specific incidence against the log of age with least squares regression. We did the analyses within each register, and also did a combined analysis, adjusting for register., Findings: We identified 6274 cases of amyotrophic lateral sclerosis from a catchment population of about 34 million people. We noted a linear relationship between log incidence and log age in all five registers: England r(2)=0·95, Ireland r(2)=0·99, Italy r(2)=0·95, the Netherlands r(2)=0·99, and Scotland r(2)=0·97; overall r(2)=0·99. All five registers gave similar estimates of the linear slope ranging from 4·5 to 5·1, with overlapping confidence intervals. The combination of all five registers gave an overall slope of 4·8 (95% CI 4·5-5·0), with similar estimates for men (4·6, 4·3-4·9) and women (5·0, 4·5-5·5)., Interpretation: A linear relationship between the log incidence and log age of onset of amyotrophic lateral sclerosis is consistent with a multistage model of disease. The slope estimate suggests that amyotrophic lateral sclerosis is a six-step process. Identification of these steps could lead to preventive and therapeutic avenues., Funding: UK Medical Research Council; UK Economic and Social Research Council; Ireland Health Research Board; The Netherlands Organisation for Health Research and Development (ZonMw); the Ministry of Health and Ministry of Education, University, and Research in Italy; the Motor Neurone Disease Association of England, Wales, and Northern Ireland; and the European Commission (Seventh Framework Programme)., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Our objective was to generate a prognostic classification method for amyotrophic lateral sclerosis (ALS) from a prognostic model built using clinical variables from a population register. We carried out a retrospective multivariate analysis of 713 patients with ALS over a 20-year period from the South-East England Amyotrophic Lateral Sclerosis (SEALS) population register. Patients were randomly allocated to 'discovery' or 'test' cohorts. A prognostic score was calculated using the discovery cohort and then used to predict survival in the test cohort. The score was used as a predictor variable to split the test cohort in four prognostic categories (good, moderate, average, poor). The accuracy of the score in predicting survival was tested by checking whether the predicted survival fell within the actual survival tertile which that patient was in. A prognostic score generated from one cohort of patients predicted survival for a second cohort of patients (r(2) = 0.72). Six variables were included in the survival model: age at onset, diagnostic delay, El Escorial category, use of riluzole, gender and site of onset. Cox regression demonstrated a strong relationship between these variables and survival (χ(2) 80.8, df 1, p < 0.0001, n = 343) in the test cohort. Kaplan-Meier analysis demonstrated a significant difference in survival between clinical categories (log rank 161.932, df 3, p < 0.001), and the prognostic score generated for the test cohort accurately predicted survival in 64% of the patients. In conclusion, it is possible to correctly classify patients into prognostic categories using clinical data easily available at time of diagnosis.

Replicable risk factors for ALS include increasing age, family history and being male. The male: female ratio has been reported as being between 1 and 3. We tested the hypothesis that the sex ratio changes with age in a population register covering the south-east of England. The sex ratio before and after the age of 51 years was compared using a Z-test for proportions. Kendall's tau was used to assess the relationship between age group and sex ratio using incidence and prevalence data. Publicly available data from Italian and Irish population registers were compared with results. There was a significant difference in the proportion of females with ALS between those in the younger group (30.11%) and those in the older group (43.66%) (p = 0.013). The adjusted male: female ratio dropped from 2.5 in the younger group to 1.4 in the older group using prevalence data (Kendall's tau = -0.73, p = 0.039). Similar ratios were found in the Italian but not the Irish registry. We concluded that sex ratios in ALS may change with age. Over-representation of younger patients in clinic registers may explain the variation in sex ratios between studies. Menopause may also play a role.

Background: Amyotrophic lateral sclerosis (ALS) is a degenerative disease of motor neurons that causes progressive paralysis and eventually results in death from respiratory failure. Environmental factors that trigger ALS might result in a pattern of geographical clustering of cases. We tested this hypothesis using the South-East England ALS population register, which covers south-east London, Kent and parts of neighbouring counties., Methods: The register's catchment area was divided into postcode districts and sectors. The expected rates of ALS (adjusted for age and sex) were compared with the observed rates using a standardised residuals method and the SaTScan programme., Results: There were 406 cases of ALS identified in the catchment area during the study period. Four of the 126 postcode districts, all in Greater London, had residuals >2.5 SDs from the mean. Similarly, there were 15 postcode sectors (out of 420) that had residuals >1.96 SDs from the mean. Nine of these were in Greater London. SaTScan identified an area that had a 5.61-km radius in which the relative risk of ALS was 1.70 (p = 0.012). This area overlapped with the postcode districts and some of the sectors identified using the residuals method., Conclusions: These findings suggest an excess of ALS cases in some postcode districts in south-east England., (2008 S. Karger AG, Basel.)