Temporal and geographic variation in United States motor neuron disease mortality, 1969-1998.
OBJECTIVE
To describe temporal trends of motor neuron disease (MND) mortality in the United States. Variations in MND by demographic variables of sex, age, geography, and race/ethnicity were evaluated to assess the possible explanations for observed trends.


METHODS
Multiple-cause mortality files from the National Center for Health Statistics for the years 1969 through 1998 were searched for all United States death records with codes corresponding to MND. Age-adjusted mortality rates were calculated by sex, race/ethnicity, age, birth cohort, and place of death.


RESULTS
Overall MND mortality rates increased from 1.25 per 100,000 to 1.82 per 100,000, representing a 46% increase during the 30-year period. Rates among women increased by 60% and continue to rise. Rates among men rose by 35% during this period but have leveled off in the most recent decade evaluated. Mortality rates among African Americans and Hispanics were approximately 50% lower than rates among non-Hispanic whites. A southeast to northwest gradient was observed when rates were grouped by 12 geographic areas. MND mortality rates per 100,000 (and 95% CI) ranged from 2.22 (1.89 to 2.55) in the Northwest to 1.57 (1.44 to 1.71) in the Southeast.


CONCLUSIONS
Variations in motor neuron disease (MND) mortality by time, race/ethnicity, sex, and geography were consistent with the hypothesis that environmental exposures, combined with factors of genetic susceptibility, play a role in the development of MND.
Noonan
Curtis W
CW
Health Investigations Branch, Division of Health Studies, Agency for Toxic Substances and Disease Registry, Atlanta, GA, USA. curtis.noonan@umontana.edu
White
Mary C
MC
Thurman
David
D
Wong
Lee-Yang
LY
D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D015331:Cohort Studies; D016208:Databases, Factual; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005843:Geography / Q000706:statistics & numerical data; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D016472:Motor Neuron Disease / Q000208:ethnology / Q000401:mortality*; D017678:Sex Distribution; D013997:Time Factors; D014481:United States / Q000453:epidemiology / Q000208:ethnology; D044465:White People / Q000706:statistics & numerical data