Nathaniel Moxley Kelly
Title of Presentation:
Driving While Impaired: Offender Typologies and Treatment Outcome Following Brief Intervention
Aims and Background: The persistently modest outcomes from remedial prevention programs in curtailing driving while impaired (DWI) recidivism have fueled interest in matching of intervention to subtypes of DWI offenders to improve outcomes. In previous research with DWI offenders, we found that brief (one 30 min session) motivational interviewing (BMI) produced a greater reduction in alcohol misuse than an information-advice intervention (IA). We have also identified two DWI typologies with distinct behavioural, psychological and neurobiological features, one consistent with heightened sensitivity to alcohol’s effect on cognitive control capacities (pDWI); and ii) the other consistent with reward deficiency syndrome (MIXED). We hypothesized that the pDWI typology shows selective treatment responsivity to BMI.
Method: DWI recidivists who participated in a randomized controlled trial (Brown et al., 2010; Ouimet et al., 2013) were classified based upon on their characteristics as belonging to either pDWI and MIXED typologies. The effects of exposure to BMI and IA interventions in each typology (i.e., pDWI-BMI vs. pDWI-IA; MIXED-BMI vs. MIXED-IA) was measured for alcohol misuse over 12-month posttreatment follow-up, and DWI violations over 5-year follow-up.
Results: BMI exerted significant large effects for reducing alcohol misuse in pDWI offenders, F(2,93) = 9.1, p < .001, 2 = .16, and significant but small effects in the MIXED offenders, F(2, 83) = 3.8, p < .03, 2 = .03, while IA exerted significant medium effects in pDWI offenders, F(2, 93) = 4.1, p = .02, 2 = .08, but non-significant effects for MIXED offenders. Typology-based differences were not detected on long-term DWI recidivism risk, but the MIXED offenders showed significantly higher risk for future DWI recidivism compared to pDWI offenders irrespective of their intervention allocation, (2(1) = 4.5, p = .04).
Conclusions: Selective treatment responsivity is supported by BMI’s greater and more durable benefits for reducing alcohol misuse in pDWI offenders than the other typology-intervention combinations examined here. Moreover, long-term DWI recidivism risk is predicted by typological classification.