Different prevalence rates of parkinson's disease in urban and rural areas: A population-based study in Taiwan

Background: Rural living has long been debated as a risk factor for idiopathic Parkinson's disease (IPD). But few community-based studies compared this difference between urban and rural areas. Methods: Population-based surveys by neurologists using a standardized diagnostic protocol were conducted in the urban areas of Keelung City and compared the prevalence rates of IPD with those we had previously determined in the rural area of Ilan County, Taiwan. Subjects were diagnosed with IPD when at least 2 of the 4 cardinal signs of parkinsonism were present and by exclusion of secondary parkinsonism. Gender-specific age-standardized prevalence rates of IPD by using the 1970 and 2000 US censuses were calculated for comparison. Results: The participation rate was 84.9%. The crude prevalence rate of IPD in persons aged 40 years and over was 706 (95% CI: 551-864) per 100,000 population. The age-adjusted prevalence rates by using the 1970 US census were 633 (95% CI: 620-646) for people aged 40 and over and 230 (95% CI: 227-234) for all ages. Our results were similar to those obtained in Sicily, Rotterdam, and 3 communities in China. Moreover, the prevalence rates of IPD in Keelung, the urban area studied, were twice as high as those in Ilan, the rural area studied (p < 0.001). Conclusions: Our results suggest that urban living is more important as a risk factor for IPD development than rural living in Taiwan.