An assessment that reliably predicts the progression of Alzheimer's disease has been developed by researchers at Baylor College of Medicine. The findings, which appear in the current edition of the journal Alzheimer's Research & Therapy, also found that those with a slower progression of the disease live longer.

"Patients and families frequently ask clinicians to predict expected rates of cognitive and functional decline, and clinicians currently have little basis for making such decisions," said Dr. Rachelle Doody, professor of neurology and director of BCM's Alzheimer's Disease and Memory Disorders Center. "We have found that a simple, calculated progression rate at the initial visit gives reliable information regarding performance over time."

Identifying factors

The BCM Alzheimer's Disease and Memory Disorders Center followed 597 patients over 15 years. The research team used a variety of standardized tests and scales to assess the ability of their method to predict functions including memory, language, arithmetic and judgment/problem solving as well as the performance of daily skills over time. By reviewing a patient's progression through those years, researchers were able to look back at base-line evaluations and follow up exams and identify those factors that were seen in patients who later progressed at slow, intermediate or rapid rates.

Researchers also found that those who fell into the slow and intermediate progression rates survived longer with those in the slowest progression rate surviving the longest.

Assessment impacts for care giving, qualify of life

Understanding the disease progression is important for care giving needs and for patient and caregiver quality of life, said Doody.

The assessment will also have applications in research studies. The measure could be used when considering a design of long duration Alzheimer's disease clinical trials.

"Currently, parallel group studies count on randomization to yield comparable placebo and treatment groups. Pre-progression rates are not assessed, yet imbalances across the treatment groups in this important variable could obscure or create treatment differences," Doody said. "Future clinical trials may benefit from gathering systematic data regarding individual symptom onset in order to perform a formal estimate of duration and to calculate pre-progression rates."

Others who contributed to the study include Drs. Valory Pavlik, Susan Rountree and Eveleen Darby, all with BCM; Paul Massman, adjunct BCM faculty; and Wenyaw Chan, department of epidemiology and biostatistics, UTHSC Houston.

Funding for the study came from the National Institutes of Health, a Zenith award from the Alzheimer's Association, the Cain Foundation and the Cynthia and George Mitchell Foundation.