Population prevalence and incidence of Parkinson's disease in an Australian community

Background: Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting older individuals. Few studies have determined the prevalence and incidence of this disease in Australia. The aim of the study was to estimate the prevalence and 10-year incidence of PD in the Australian community. Methods: In the Blue Mountains Eye Study (BMES), a population-based health survey of Australian residents aged 49 years or more, we determined the cross-sectional prevalence (BMES2, 1997-1999, n = 3509) and 10-year incidence (BMES1, 2 and 3, 1992-1994, 1997-1999 and 2002-2004, respectively, n = 2545) of PD. We screened participants who took PD medications. PD diagnosis was confirmed by contacting the participant's medical/general practitioners. Results: Nineteen new cases of PD were identified over the 10-year period, a 10-year incidence of 0.84% (95% confidence interval (CI) 0.54-1.33%). In the cross-sectional study, 16/3509 participants were confirmed to have PD (0.46%), with age-specific prevalence rates of 0.48% in persons aged 60-69 years, 0.82% for ages 70-79 years and 0.56% in persons aged 80 years or older. No PD cases were identified among participants less than 60 years of age. When age standardized to the 2001 Australian population, the prevalence of PD was 362 per 100 000 (95%CI 183-541) among persons aged 50 years or older and 104 per 100 000 for the Australian population at all ages, assuming no prevalent cases in persons aged less than 50 years. Conclusion: This study estimates a 0.46% (95%CI 0.23-0.68) prevalence of PD patients treated with medications aged 50 years or older and a 10-year incidence of 0.84% (95%CI 0.54-1.33).