A perceived cluster of amyotrophic lateral sclerosis cases in a Massachusetts community.
We investigated a report of a perceived cluster of amyotrophic lateral sclerosis (ALS) in Middleborough, Mass. Although an increase in ALS incidence was observed [2.51 deaths/100,000 person-years (p-y)], relative to the statewide rate over the years 1969-1985 (1.26/100,000 p-y), it was not statistically significant at the 95% confidence level. Problems in evaluating possible neurological disease clusters and their association with environmental exposures are presented.
Proctor
S P
SP
Department of Neurology, Boston University School of Medicine, MA 02118.
Feldman
R G
RG
Wolf
P A
PA
Brent
B
B
Wartenberg
D
D
D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000209:etiology / Q000401:mortality*; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D012307:Risk Factors