The study was led by principal investigator Meredeth A. Rowe, RN, PhD, FGSA, FAAN, professor and endowed chair at the University of South Florida College of Nursing. The findings were published online last month in the Journal of the American Geriatrics Society: Missing Drivers with Dementia: Antecedents and Recovery.

Based on the study results, the research team reported several recommendations to help guide local policies and training for Silver Alert-type programs that broadcast information about missing seniors with Alzheimer's disease, dementia or other cognitive deficits, including:

- Rapid, direct notification of law enforcement agencies as well as equipping officers a mechanism for quickly assessing the cognitive status of drivers is critical. Law enforcement officers are more likely than citizens or family members to discover missing drivers with dementia.

- More detailed information about a missing individual, not just a description of the car being driven, may better assist law enforcement officers and citizens in rescuing lost drivers who have left their vehicles to wander on foot.

- State and federal agencies planning a Silver Alert program need to develop policies and procedures that recognize the distinct differences between those missing while driving and those lost while walking.

- Retirement from driving is the only preventive option when individuals can no longer safely operate a motor vehicle because dementia interferes with their ability to retain and use new information.

"With the baby-boomer generation getting older, the number of the people living with Alzheimer's disease is on the rise," Dr. Rowe said. "Most Americans depend on driving their own car to meet their transportation needs, even for the most basic needs such as food. It will be critical to identify other means of transportation for people with dementia (PWD) to facilitate driving retirement. This strategy will be the most effective intervention to reduce and prevent incidents of missing PWDs. Strategies commonly recommended, such a hiding the car keys, are potentially protective only in a small number of cases."

According to Alzheimer's Association, 5.4 million Americans live with Alzheimer's disease, including 800,000 who live alone. One in eight older Americans lives with the memory-robbing disease, including 450,000 Floridians age 65 or older. These statistics highlight the need to find more effective ways to search for missing drivers with dementia and reduce missing incidents.

Dr. Rowe and her colleagues analyzed 156 records from the Florida Silver Alert program for October 2008 through May 2010. These alerts are issued on digital highway signs and news broadcasts in Florida to assist law enforcement officials and the general public in identifying and safely returning cognitively impaired drivers.

The researchers found that most missing drivers were men, ages 58 to 94, who were cared for by a spouse. Most got lost on routine, caregiver-sanctioned trips to usual locations. Only 15 percent were found while driving, with most discovered in or near a parked car -- and law enforcement officers recovered the large majority of drivers with dementia.

In addition, only 40 percent were found in the county where they were reported missing, and 10 percent were found in a different state. Another 15 percent were found in dangerous situations such as stopped on railroad tracks. There was a 5 percent mortality rate in the study population, with those living alone more likely to be found dead than alive.

"While some PWDs may continue to drive safely, it is imperative that we identify individuals who will get lost, determine predictors of modifiable outcomes, and establish policies that will improve location of those individuals who get lost," said study co-author James E. Galvin, MD, MPH, professor of neurology and psychiatry New York University Langone Medical Center.

A comprehensive Silver Alert program that includes law enforcement and community education as well as rapid alerts is critical to finding missing drivers, the researchers conclude. Their findings led to recommendations for an additional study on how notifications be more effectively delivered to facilitate increased recoveries from "Good Samaritan" citizens.

The researchers emphasize that getting cognitively impaired people to retire from driving may be the single most effective measure for prevent missing incidents that may lead to injury or death.

"Important aspects of successful driving retirement include a partnership between the healthcare practitioner and caregiver to support the decision for driving retirement, the identification of

local and state programs… and assistance in finding alternative forms of transportation in the community," they report.