title: A case-control study of smoking habits, dementia, and other illnesses in idiopathic Parkinson's disease.
abstract: From 1967 to 1979, 118 incident cases of idiopathic Parkinson's disease (IPD) and 236 age- and sex-matched controls from Rochester, MN, were identified. Medical records on patients and controls for 40 years preceding the diagnosis of IPD were reviewed. The relative risk (RR) for ever-smoked and IPD was not significantly different from unity (RR = 0.7, 95% confidence interval = 0.4 to 1.2). The mean age at diagnosis of IPD was significantly younger (p = 0.007) in the ever-smokers (68.8 years) compared with never-smokers (73.8 years), although this needs to be interpreted cautiously. It is concluded that smoking had no effect on the development of IPD. Within 5 years after the index date, a new diagnosis of dementia was made more often in cases than in controls (p = 0.01). Relative risk of IPD significantly increased when prior diagnosis of psychoneurosis and psychosomatic illness had been made.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003704:Dementia / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000209:etiology*; D012306:Risk; D012907:Smoking