Potentially driver-impairing (PDI) medication use in medically impaired adults referred for driving evaluation.
BACKGROUND
Potentially driver-impairing (PDI) medications have been associated with poorer driving performance and increased risk of motor vehicle collision.


OBJECTIVE
To describe the frequency of medication use and to determine the association between routine use of PDI medications and performance on driving and cognitive tests.


METHODS
A total of 225 drivers with medical impairment (mean age 68 ± 12.8 years, 62.2% male) were referred to an occupational therapy-based driving evaluation clinic. Medication lists were reviewed to identify PDI drugs, as defined by a previous study examining medications and crash risk. Outcome variables included road testing on the modified Washington University Road Test and cognitive scores on Trail Making Test Parts A and B, Snellgrove Maze Task, Clock Drawing Task, Driving Health Inventory (DHI) Useful Field of View, DHI Motor Free Visual Perceptual Test, Epworth Sleepiness Scale (ESS), Geriatric Depression Scale, and Functional Assessment Questionnaire.


RESULTS
PDI medication use was documented in 68.9% of the sample, with the average subject taking 1.4 PDI drugs. Drivers taking routine PDI medications had a mean ESS score of 7.8 compared to 6.0 in the control group, suggesting increased somnolence (P = .007). Total number of routine medications, regardless of PDI designation, also correlated positively with ESS scores (P = .023).


CONCLUSIONS
Use of PDI medications was associated with informant ratings of daytime drowsiness on the ESS, which has been linked to motor vehicle crash risk. Further investigation of individual drug classes is warranted using larger sample sizes and a high-powered study design.
St. Louis College of Pharmacy, St. Louis, MO, USA.
Amanda J
AJ
Hetland
David B
DB
Carr
Michael J
MJ
Wallendorf
Peggy P
PP
Barco
D000063:Accidents, Traffic / Q000517:prevention & control*; D000368:Aged; D001334:Automobile Driving; D016022:Case-Control Studies; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D018570:Risk Assessment; D012894:Sleep Stages / Q000187:drug effects; D011795:Surveys and Questionnaires
D006993:Hypnotics and Sedatives
driving safety; drugs and driving; medically impaired drivers; older adult drivers; potentially driver-impairing medications