Why the increase?
The increase in cases could be the result of the more comprehensive estimation model used, the researchers noted. Or it could be improved detection, the aging population, a rise in sedentary lifestyles, increased exposure to environmental risk factors, or even the sharp decline in smoking in the United States, as some studies have shown that smokers have a lower Parkinson’s disease risk.
“The short answer is, we don’t know; and the long answer is, it’s all the above,” Dr. Beck said.
Although about 15% of Parkinson’s disease cases have a genetic basis, the cause is unknown in the majority of cases. In addition, diagnosis is difficult because there is no blood test or scan that detects the disease.
“Diagnosis requires a skilled clinician with real familiarity with Parkinson’s. And we have a real shortage of neurologists in this country to not only be able to diagnose but also to treat the condition,” Dr. Beck said.
That was one motivation for doing the study: to highlight what experts say is a pending clinical crisis for patients with Parkinson’s disease, he added.
The investigators also wanted to raise awareness about the scope of the disorder – not just about prevalence and incidence but also what those data mean for the health care industry, research aims, drug development and health care coverage, and policies.
In a 2020 study, the same researchers calculated a cost of $52 billion per year for medical and nonmedical costs related to Parkinson’s disease, which works out to about $26,000 per year per patient. That figure is expected to surpass $79 billion by 2030.
“This is an urgent condition for many people who live with the disease. And to the extent we can get our country to recognize that and really make the investment now, this is an area where a stitch in time saves nine,” Dr. Beck said.
“If we can invest some money now, we have a chance to really make a difference in the future,” he added.
‘Groundbreaking’ findings
Commenting on the findings, Jori Fleisher, MD, MSCE, associate professor of neurological sciences at Rush University Medical Center, Chicago, called the results “groundbreaking” and said that they validate what clinicians have been seeing in real-world practice.
“The findings reflect what a lot of us in practice have been appreciating anecdotally, which is that it seems that Parkinson’s is being diagnosed more frequently and that the incidence has been rising,” said Dr. Fleisher, who was not involved with the study.
She noted that the use of multiple datasets is one element of the methodology that makes the data so significant.
“There has been great work out of individual centers; but no matter how good your study methods are within that one population, you’re drawing conclusions based on that one population,” Dr. Fleisher said.
This research, together with the previous work by the group on prevalence data, could go a long way toward raising awareness about the scope of Parkinson’s disease in the United States – which could lead to earlier diagnosis, more research funding, and increased attention on the need for more clinicians who specialize in movement disorders, she added.
“This should increase research funding across the spectrum, including everything from the basic science to translational research, clinical research and implementation, and health services research,” Dr. Fleisher said.
The study was supported by the Parkinson’s Foundation, The Michael J. Fox Foundation for Parkinson’s Research, and the Institute for Clinical Evaluative Sciences. Dr. Beck and Dr. Fleisher reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.