Ce. Clarke, MORTALITY FROM PARKINSONS-DISEASE IN ENGLAND AND WALES 1921-89, Journal of Neurology, Neurosurgery and Psychiatry, 56(6), 1993, pp. 690-693
Mortality from Parkinson's disease in England and Wales was re-examine
d using published government statistics. The 300% increase in the crud
e mortality rate between 1921 and 1989 was largely attributable to the
increase in the elderly population who suffer a higher prevalence of
the disease. The dramatic fall in 1940 and rise in 1984 were artefacts
caused by changes in certification. Age-specific mortality fell after
1940 in all groups below 70 years and in both sexes, but increased in
those over 75 years. Analysis by birth cohort showed a progressive de
cline in mortality at younger ages with successive cohorts but stable
mortality in the elderly. Younger patients were probably misclassified
cases of ''late-onset'' Parkinsonism following encephalitis lethargic
a who can be differentiated from older cases of idiopathic Parkinson's
disease. Mortality decreased in all age groups in the 1970s but then
increased in the early 1980s. This is comparable to trends in the Unit
ed States and Scandinavia and suggests that the beneficial effects of
levodopa delay death for several years.