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.

Mortality of Parkinson's disease by Hoehn-Yahr stage from community-based and clinic series [Keelung Community-based Integrated Screening (KCIS) no. 17)].

PURPOSE: We aimed to quantify the mortality reduction by which the early detection of Parkinson's disease (PD) within a community-based study could reduce the number of advanced cases. METHODS: Data used in this study were derived from two community-based surveys and from a clinical series of PD cases identified from a medical centre. The cumulative survival by Hoehn-Yahr (H-Y) scale was estimated and the mortality reduction derived from a community-based survey was predicted. RESULTS: A total of 117 PD patients were detected through two community-based approaches. By comparing the H-Y stage distribution of screen-detected cases with those from the clinical series, a 22.5% excess in the number of early PD (H-Y stage I and stage II) were identified with screening. The risk ratios of being H-Y stage III or severe for community-based detected cases versus clinical series were 0.49 (95% confidence interval: 0.30-0.78). The total death rate adjusted by H-Y stage distribution was 21% and 28% for cases from community and clinical series, respectively. CONCLUSIONS: The present study revealed that early detection of PD through a community-based survey may reduce 51% incidence of stage III or more severe PD at diagnosis, leading to a 25% reduction in mortality.

Natural history and effectiveness of early detection of Parkinson's disease: results from two community-based programmes in Taiwan (KCIS no. 11).

OBJECTIVES: The natural course of Parkinson's disease (PD), as measured on the Hoehn-Yahr (H-Y) scale, and the impact that early detection would have on prognosis for those with the disease, has barely been addressed since the introduction of L-dopa. This study aimed to elucidate the natural history of PD and effectiveness of early detection in reducing advanced disability and mortality. METHOD: A total of 21 362 participants aged 40 years or older were invited to two community-based programmes for the early detection of PD. The step-by-step annual progression rates from H-Y stage I to stage IV or V, and cumulative survival rates, by the H-Y scale, were estimated and applied to simulated data to assess the impact of different screening intervals upon stage at diagnosis and subsequent survival. RESULTS: The average duration in stages I, II and III was estimated as 2.83, 6.62 and 1.41 years, respectively. The average delay time before deteriorating into H-Y stage III was 9.45 year. Application of these parameters to simulated model predicted a 36% (95% CI: 28-39%), 26% (95% CI: 20-32%) and 19% (95% CI: 13-24%) reduction in death for annual, 5-yearly and 10-yearly screening programmes, respectively. CONCLUSION: The present study recommended a 5-yearly screening programme, with 74% of PD cases prevented from progressing to H-Y stage III or worse within 10 years of diagnosis, and leading to a corresponding 26% reduction in mortality.

Population-based survey on prevalence of adult patients with epilepsy in Taiwan (Keelung community-based integrated screening no. 12).

PURPOSE: To determine the prevalence rate and patterns of adult patients with epilepsy in Taiwan, we conducted a community-based neuroepidemiological survey. METHODS: Epilepsy was detected by neurologists using one-stage method. It was integrated into a community health screening service and performed from 1 January 2001 to 31 December 2001 in Keelung, a northern city in Taiwan. A total of 13,663 subjects aged 30 years or older participated in this survey. RESULTS: There were 52 patients with epilepsy in this study. Among them, 37 were patients with active epilepsy. The age-adjusted prevalence rate of active epilepsy above 30 years old was 2.77/1000 (to the 1980 US population) with the highest rate in subjects aged 40-49 years (4.0/1000). There was a trend of higher prevalence rate in male than in female. The most common seizure type was complex partial seizure (46.0%). Using one-stage detection method, we found nine (24.3%) patients with active epilepsy who had never been diagnosed before. Among the patients with active epilepsy, 35.1% were symptomatic cases. Head injury (13.5%) is the leading cause, followed by CNS infection (8.1%), stroke (5.4%) and perinatal insult (5.4%). The lifetime prevalence rate of epilepsy (including active epilepsy and epilepsy in remission) was 3.14/1000 for age above 30 years. CONCLUSIONS: Comparing to previous epilepsy survey in 1993, our results showed that the prevalence rate of epilepsy was rather stable over the past decade in northern Taiwan. Head injury is the leading cause responsible for active epilepsy. Improving public safety is an important public health issue which may help to reduce occurrence of epilepsy.