DRIVING Dr. Bill Thoo Dr. Bill ThooGeriatrician2010

DEMOGRAPHICS Less likely to drive if older or sickerLess likely to drive if older or sicker –OR 1.11 (95% CI 1.10–1.14) for each additional year of age –OR 1.15 (95% CI 1.04–1.27) for each additional medical condition. Less likely to drive if not married or partneredLess likely to drive if not married or partnered –OR 1.75 (95% CI 2.5–1.23) for divorced or separated adults –OR 1.39 (95% CI 1.72–1.12) for widowed participants –OR 2.63 (95% CI 3.7–1.85) for persons who were never married. Ross, JAGS 2009Ross, JAGS 2009

DEMOGRAPHICS Men more likely to continue driving than womenMen more likely to continue driving than women –Dementia – 42% men vs 11% women –Cognitive impairment – 63% men vs 19% women –Impaired visual acuity – 57% men vs 26% women Ross, JAGS 2009Ross, JAGS 2009

PREDICTORS OF ACCIDENT Age a weak predictor by itselfAge a weak predictor by itself Global cognitive scoresGlobal cognitive scores Cognitive flexibilityCognitive flexibility Visual perception and Visual fieldsVisual perception and Visual fields Visuo-constructional abilityVisuo-constructional ability Mobility and falls riskMobility and falls risk

PREDICTORS OF ACCIDENT Subset of community sample with driver’s licenseSubset of community sample with driver’s license >70 years old>70 years old MMSE >23/30MMSE >23/30 OT driving assessment outcomeOT driving assessment outcome Wood, JAGS 2008Wood, JAGS 2008

PREDICTORS OF ACCIDENT Positive predictors of failing a driving test.Positive predictors of failing a driving test. –Number of kilometres driven –Useful field of view test –Dot motion sensitivity –Colour choice reaction time –Trails B test –Knee extension strength –Postural sway Wood, JAGS 2008Wood, JAGS 2008

PREDICTORS OF ACCIDENT Benzodiazepine useBenzodiazepine use –Initiation – 1.45 OR risk of accident –Long term use – 1.26 OR risk of accident (Hemmelgarn, JAMA 1997)(Hemmelgarn, JAMA 1997) No medical standard for benzodiazepine use and drivingNo medical standard for benzodiazepine use and driving (Austroads)(Austroads)

DRIVING AND DEMENTIA Conditions for unconditional license not met if:Conditions for unconditional license not met if: –Memory impairment –Visuospatial impairment –Impaired insight or judgement –Problematic hallucinations or delusions Conditional license:Conditional license: –Depending on doctors report (periodic review) –Response to treatment (Austroads)

DRIVING AND DEMENTIA 14/30 Alzheimer disease subjects crashed over 5 years (mean MMSE 19.9 at time of crash) versus 2/20 controls14/30 Alzheimer disease subjects crashed over 5 years (mean MMSE 19.9 at time of crash) versus 2/20 controls MMSE, disease severity, disease duration not predictiveMMSE, disease severity, disease duration not predictive Most crashes at intersections or changing lanesMost crashes at intersections or changing lanes (Friedland, Annals of Neurology 1988)(Friedland, Annals of Neurology 1988)

DRIVING AND DEMENTIA In driving simulation study, increased accident rate when information systems stressed by new stimuliIn driving simulation study, increased accident rate when information systems stressed by new stimuli –eg. Car pulls out in front of subject unexpectedly, not routine driving (Rizzo, Alzheimers Disease and Associated Disorders 2001)(Rizzo, Alzheimers Disease and Associated Disorders 2001)

INTERVENTIONS Yearly licensing renewal may reduce road fatalitiesYearly licensing renewal may reduce road fatalities –In person license renewal reduces deaths in over 85 yr age group (Grabowski, JAMA 2004) –Visual acuity testing >80 years Florida in 2004 reduced deaths (McWrin, Arch Ophthalm 2008)

INTERVENTIONS Education does not reduce accident ratesEducation does not reduce accident rates –>60 yrs, visual deficit, slowed visual processing, accident last 12 months, attending eye clinic –Self reported avoidance of challenging driving conditions –Improved self regulatory behaviours –No accident reduction (Owsley, American Journal of Preventative Medicine 2004)(Owsley, American Journal of Preventative Medicine 2004)

INTERVENTIONS Driving restrictionsDriving restrictions –Problematic in patients with dementia

INTERVENTIONS OT Driving AssessmentOT Driving Assessment

CONSEQUENCES Cost of OT driving assessmentCost of OT driving assessment Enforcing restrictionsEnforcing restrictions Social isolationSocial isolation DepressionDepression Increased dependencyIncreased dependency Breaking of a therapeutic relationshipBreaking of a therapeutic relationship Reluctance to report dementiaReluctance to report dementia Insurance claims when not eligible to driveInsurance claims when not eligible to drive