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From: "Ansa Ojanlatva" <[log in to unmask]> > A second question, perhaps more along the lines of your personal expertise, has to do with epidemiology itself. I recently saw a mention somewhere that there is no PD in really old people... The following excerpts may give some idea of the problems in compiling prevalence and incidence data - "There are virtually no accurate figures of incidence and prevalence of PD, and worldwide estimates vary from 1:1000 to 2:1000, with this figure increasing for those over 65 to 1:100 and 4:100 in the over-70 population. A survey carried out in South Australia in 1985 resulted in a figure of 2300 people in South Australia, which would translate to an incidence of 1.6:1000. This could mean that about 25,000 people in Australia have PD." www.mydr.com.au "A prevalence study of Parkinson's disease (PD) was conducted in the rural town of Nambour, Australia. There were 5 cases of PD in a study population of 1207, yielding a crude prevalence ratio of 414 per 100,000 (95% confidence interval)." The epidemiology of Parkinson's disease in an Australian population. Neuroepidemiology, 17 : 310-317. "The prevalence of idiopathic Parkinson's disease (IPD) in Australia is unclear. We estimated the prevalence of IPD, and other forms of parkinsonism, through the study of typical caseloads in general practice. A random sample of general practitioners (GPs) throughout Queensland (401 responses from 528 validated practice addresses) was asked to estimate the numbers of patients with IPD and parkinsonism seen in the preceding year. The estimated prevalence of diagnosed IPD in Queensland was 146 per 100 000 (95% CI = 136-155). A further 51 per 100 000 in the population were suspected by doctors to have IPD without formal diagnosis, whereas another 51 per 100 000 people may have non-idiopathic parkinsonism. Idiopathic Parkinson's disease was more common in rural than metropolitan areas. Although most GPs were confident in making diagnoses of IPD, the majority had little or no confidence in their ability to treat the disease, especially in its later stages. Support from neurologists was perceived by GPs to be very good in cities, but poor in remote areas." Prevalence of Parkinson's disease in metropolitan and rural Queensland: A general practice survey. Journal of Clinical Neuroscience, 13 3: 343-348. Questions I ask myself 1. Why is prevalence estimated against the entire population, if only the elderly are susceptible? 2. What is the statistical relevance if any, of very small data sets? 3. Why does data not include PWP being treated by neurologists. (Our research indicates that many GP's are unaware that their patients have PD, especially if visits to a (new) GP postdate the diagnosis of PD. And on and on.... Our research showed patients as young as the 15-19 quintile, and as old as the 95-99 quintile. Our research methodology was estimated by Federal Statisticians from the Health Insurance Commission to have trapped 87.2% of all PWP in Australia. Using algorithms developed excusively between our research team and these statisticians, we were able to identify individuals with PD, although for reasons of privacy, the data seta relayed to us did not include data which would identify individuals. The uniqueness of individuals only emabled us to identify the total of patients within geographically defined areas. But the major aspect of our research was the comparison of the data on PWP's against equivalent census date for the same defined areas, in the same time periods. This, to the best of my knowledge, is the first study to do so. I am unable at this time to give more detailed data, as I and my wife are in respite care at a nursing home, and I have only my laptop with me, and it does not have my research data on it. Dr. J. F. Slattery PhD Soc Sc ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn