An Ambitious Study of World Wide Prevalence of PARKINSON’S DISEASE
In an effort to prepare public health systems to better serve future populations, a team of investigators from the University of Calgary in Alberta, Canada reviewed and analyzed over 4,000 epidemiological studies of PARKINSON’S DISEASE conducted throughout the world between the years of 1985 and 2006. This study was part of a larger study that actually looked at 15 different neurodegenerative diseases to ensure effective planning for medical services for populations that are increasing and now include larger numbers of elderly citizens who are most affected by diseases of aging such as Alzheimer’s disease and PARKINSON’S DISEASE. Many nations of the world will be facing health care costs for their people that will seriously strain, if not exhaust their available finances.
Although they found over 4,000 epidemiological studies from all over the world, there were many obstacles to distilling the information. Each study had unique differences in the demographics of the participants and the methodology of the study. Studies using only medical information did not count people who did not seek medical treatment; drug studies were also affected by cultural differences as well as the financial burdens of obtaining the medications. Slight differences in diagnostic criteria can increase or decrease the numbers of subjects included. Some subjects may have been misdiagnosed; others may not have had access to good medical care. Another impediment to research on medical records is government restrictions on access to the personal data contained in those records. Overcoming these disparities in information required detailed screening of eligibility requirements to meet the standards of this study. Ultimately, only 134 of the original 4,219 research reports met those standards. Those were reduced even further to allow for 47 studies that were considered to meet random population sample and diagnostic criteria
The results of this study found fascinating differences in geographic distribution, age and sex. Analysis of the data show that PARKINSON’S DISEASE is increasing worldwide, beginning with the 40 to 49 year old group, and increasing substantially in each age group. Interestingly, in the 70 to 79 year old group there was a significant decrease (646 per 100,000 individuals) compared to Europe, North America and Australia (1,602 per 100,000 individuals). This highest affected numbers were in the over 80 age group, with 1,903 individual per 100,000. One reason for the higher numbers in the over 80 group may be the improvements in treatment for PARKINSON’S DISEASE as well as higher quality general care has improved chances for survival to this age and decreased mortality rates for everyone.
Division by sex showed that in all the age groups, males had only a slight increase over females. But in the 50 to 59 age group, males had a much higher prevalence, more than three times higher than females in that same age group. It has been suggested that estrogen in females may increase the available dopamine in the striatum that may present as a milder version of PARKINSON’S DISEASE that progresses more slowly.
While the genetics and environmental factors that lead to PARKINSON’S DISEASE are beginning to be investigated, these new studies may also have a major impact on the type and quality of medical care available to this population. This study shows that while the world’s population is now living longer, there is also an increased prevalence in PARKINSON’S DISEASE that will require effective planning for public health care to implement resources and availability of quality care for the increased numbers of the aging population.
Review by Marcia McCall