The goal of this project was to determine if there are practical means to obtain information about drug usage by older drivers under everyday, “real world” conditions that are valid and reliable, and to measure the consequences of multiple drug use for safe driving. Further goals were to identify candidate methodologies for carrying out such studies that are both cost-effective and likely to be successful in obtaining a diverse and representative sample of older drivers. These objectives were accomplished through the following tasks: a literature review; a brainstorming session including professionals with expertise in polypharmacy and driving performance measurement; and focus groups with older drivers. The literature review, published by NHTSA as a stand-alone document, contains three main sections. The first reviews the prevalence of medication use by community-dwelling older persons, the physiological/metabolic effects of specific drugs and drug classes, and the known effects on driving ability. The next discusses the strengths and weaknesses of various methods that may be used to learn which prescription and over-the-counter drugs are being taken by older adults, including a consideration of which factors most strongly affect compliance with a medication regime, and which factors influence older persons’ willingness to participate in studies aimed at obtaining such information. The last section examines onroad, closed course, and simulation methods that have been applied in prior studies of drug use and driving functioning. A one-day brainstorming session was conducted to afford guidance in the development of future NHTSA research plans for measuring medication use and driving performance. Project staff and consultants prepared discussion materials that were distributed in advance to 13 panel members, who also completed rating scale exercises to measure differences of opinion with respect to the practicality, reliability, and costeffectiveness of various research methodologies. Four focus groups were conducted with drivers age 55 to 85 in the Tampa, FL and Philadelphia, PA vicinities to better understand the perceptions and concerns that older drivers may have about participating in future NHTSA-sponsored studies where they would be asked to disclose their usage of prescription and over-the-counter medications, and participate in an assessment of their driving abilities. Results were summarized for use in planning later NHTSA research activities. (Author/publisher)
Abstract