Incidence of Parkinson's disease in Singapore.

To investigate the incidence of Parkinson's disease (PD) in Singapore, a parkinsonism-free cohort of 14,835 participants was followed-up and incident cases of PD identified through phone interviews, medical record reviews and a hospital's database. A movement disorders specialist subsequently verified the diagnosis through a medical records review. The age and sex-adjusted (US 1990 population) incidence rate was 32 per 100,000 person years for individuals aged 50 years and above. The rates differed between Chinese, Malays and Indians (p=0.03). The difference in inter-racial rates needs to be interpreted with caution in view of the small numbers. The incidence of PD in Singapore is comparable with that in Western countries.