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Tracking Parkinsonís Progression Over the Long-Term For Less

A new study funded largely by the Parkinson’s Disease Foundation (PDF) which followed more than 400 people with Parkinson’s disease (PD) for nearly ten years found a reliable low-cost method for maintaining contact with participants and tracking their disease progression over time, which may help future clinical trials. The results appear in the February 11 online edition of Movement Disorders.

In order to better understand how Parkinson’s disease progresses, to find potential biomarkers and to track any side effects of treatments, researchers need to follow large numbers of people with PD over a long period of time. Typically, at the beginning of a clinical trial, hundreds of people with PD undergo an in-depth health assessment, often when they are in an early stage of disease. But participants are not usually monitored after the trial ends. In addition, high rates of attrition (participants leaving the study) hinder scientists’ attempts at long-term follow-up and put a study’s integrity at risk (because those that leave the study may be different or show a different result than those who continue).

The new research, led by Caroline Tanner, M.D., Ph.D., at The Parkinson’s Institute and Clinical Center in Sunnyvale, CA, tested whether mail and telephone contact provide a practical follow-up method. Dr. Tanner and colleagues enrolled 422 participants in their study, called Follow-up of Persons With Neurologic Diseases (FOUND-PD), who were also enrolled in another, multi-center, study. At the start of both studies, none of the participants were receiving levodopa therapy. A neurologist evaluated all participants using standard PD rating scales. Assessments were carried out in the clinic only for the first few years, then both in the clinic and by mail survey for up to four years. Beyond that, the researchers continued following up with mailed questionnaires and telephone calls for up to two years. 


  • The researchers proved their approach was effective; they were able to maintain contact with nearly all study participants despite participants being at several different centers.
  • More than 80 percent of the time, participants’ self-reports and doctors’ evaluations – both reporting on symptoms and side effects, and PD medication regimens – were in agreement.

What Does It Mean?

In a time of rising costs for clinical trials and reduced resources, this study showed that using simple, cost-effective techniques, like postcards and phone calls, it was possible to maintain contact with a large group of trial participants for a long period of time, ensuring the integrity and validity of study results. Moreover, the FOUND study found that self-reported assessments of PD status were reasonably accurate compared to assessments made by a movement disorder specialist, allowing for continued data gathering and analysis – also at a significantly reduced expense.

Because of the high costs of long-term follow up of study participants, long-term prospective studies in PD are lacking. The authors’ suggested methodology of using mail and phone may allow researchers to continue follow study participants for a long period of time. While not studied here, electronic means of follow-up, including emails may further simplify the process as well. 

Reference: Tanner CM, Meng CC, Ravina B, Lang A, Kurlan R, Marek K, Oakes D, Seibyl J, Flagg E, Gauger L, Guest DD, Goetz CG, Kieburtz K, Dieuliis D, Fahn S, Elliott RA, Shoulson I (2014) A practical approach to remote longitudinal follow-up of Parkinson's disease: The FOUND study. Mov Disord. DOI: 10.1002/mds.25814

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Source Date: Feb 24 2014