Sacha Dubois

The Impact of Benzodiazepines on Safe Driving

Objective. Benzodiazepines are prescribed to relieve anxiety and aid sleep. Studies demonstrate that benzodiazepines increase odds of crash involvement, but little evidence exists regarding their impact on crash responsibility. We examined the impact of benzodiazepines on crash responsibility by drug half-life and driver age, using a case-control design with drivers aged 20 and over involved in fatal crashes in the United States from 1993–2006. Methods. Drivers (all with BAC = 0) were classified as having no benzodiazepines detected versus short, intermediate, or long half-life benzodiazepines. Cases were drivers with at least one potentially unsafe driving action (UDA) in relation to the crash (e.g., speeding), a proxy measure for crash responsibility; controls had no UDAs recorded. Odds ratios (ORs) of any UDA by benzodiazepines half-life exposure were calculated, with adjustment for age, sex, other medication usage, and prior driving record. Results. Compared with drivers not using benzodiazepines, drivers taking intermediate or long half-life benzodiazepines demonstrated increased odds of an UDA from ages 25 (intermediate OR: 1.59; 95% CI = 1.08, 2.33; long OR: 1.68; 95% CI = 1.34, 2.12) to 55 (intermediate OR: 1.50; 95% CI = 1.09, 2.06; long OR: 1.33; 95% CI = 1.12, 1.57). Drivers taking short half-life benzodiazepines did not demonstrate increased odds compared to drivers not using benzodiazepines. Conclusions. Given the potential impact of benzodiazepines on driver safety, further experimental research is needed to better understand the effect of benzodiazepines on crash responsibility.

Bisphosphonate-associated Osteonecrosis of the Jaw in Ontario: A Survey of Oral and Maxillofacial Surgeons

Objective. Osteonecrosis of the jaw (ONJ) in association with use of bisphosphonate (BP) has been described primarily in cancer patients receiving high-dose intravenous BP. The frequency of the condition in patients with osteoporosis appears to be low. We evaluated the frequency of BP-associated ONJ in Ontario in the cancer population and in those receiving BP for osteoporosis and metabolic bone disease. Methods. A survey developed by representatives of the Ontario Society of Oral and Maxillofacial Surgeons was mailed to Ontario oral and maxillofacial surgeons (OMFS) in December 2006, asking oral surgeons to provide information on cases of ONJ seen in the previous 3 calendar years (2004 to 2006). OMFS were subsequently contacted by telephone if they had not responded or if they had reported cases of ONJ. The frequency of ONJ in association with BP use was estimated from the number of patients with filled prescriptions for BP in Ontario between 2004 and 2006. The cumulative incidence of ONJ was calculated separately for patients using intravenous (IV) BP for cancer treatment and for patients using oral or IV BP for osteoporosis or other metabolic bone disease. Results. Between 2004 and 2006, 32 ONJ cases were identified. Nineteen patients received IV BP for cancer treatment and 13 patients received oral or IV BP for osteoporosis or metabolic bone disease. Over a 3-year period the cumulative incidence of BP-associated ONJ was 0.442% of cancer patient observations (442 per 100,000) and 0.001% of osteoporosis or other metabolic bone disease observations (1.04 per 100,000). The relative risk of low dose IV/oral BP-associated ONJ was 0.002 (95% CI 0.001, 0.005) compared to high-dose IV BP. Other risk factors for ONJ were present in all cases in whom detailed assessment was available. The median duration of exposure to BP was 42 months (range 36 to 120 mo) and 42 months (range 11 to 79 mo) in osteoporosis patients and cancer patients, respectively. Conclusion. Over a 3-year period, the cumulative incidence for BP-associated ONJ was 0.442% of cancer patient observations (442 per 100,000) and 0.001% of osteoporosis or metabolic bone disease observations (1.04 per 100,000). This study provides an approximate frequency of BP-associated ONJ in Canada. These data need to be quantified prospectively with accurate assessment of coexisting risk factors.

The association between opioid analgesics and unsafe driving actions preceding fatal crashes.

Currently, most epidemiological research into the impact of opioid analgesics on road safety has focused on the association between opioid use and traffic crash occurrence. Yet, the role of opioid analgesics on crash responsibility is still not properly understood. Therefore, we examined the impact of opioid analgesics on drivers (all had a confirmed BAC=0) involved in fatal crashes (1993-2006) using a case-control design based on data from the Fatality Analysis Reporting System. Cases had one or more crash-related unsafe driving actions (UDA) recorded; controls had none. We calculated adjusted odds ratios (ORs) of any UDA by medication exposure after controlling for age, sex, other medications, and driving record. Compared to drivers who tested negative for opioid analgesics, female drivers who tested positive demonstrated increased odds of performing an UDA from ages 25 (OR: 1.35; 95% CI: 1.05; 1.74) to 55 (OR: 1.30; 95% CI: 1.07; 1.58). For male drivers this was true from ages 25 (OR: 1.66; 95% CI: 1.32; 2.09) to 65 (OR: 1.39; 95% CI: 1.17; 1.67). The detection of opioid analgesics was not associated with greater risk of an UDA for older drivers. Research is necessary to examine why these age differences exist, and if possible, to ensure that opioid analgesics do not contribute to crashes.

The combined effects of alcohol and cannabis on driving: Impact on crash risk

BACKGROUND/OBJECTIVES Driving under the influence of alcohol or cannabis alone is associated with increased crash risk. This study explores the combined influence of low levels of alcohol (BAC≤0.08) and cannabis on crash risk. MATERIALS AND METHODS Drivers aged 20 years or older who had been tested for both drugs and alcohol after involvement in a fatal crash in the United States (1991-2008) were examined using a case-control design. Cases were drivers with at least one potentially unsafe driving action (UDA) recorded in relation to the crash (e.g., weaving); controls had none recorded. We examined the prevalence of driving under the influence of alcohol, cannabis, and both agents, for drivers involved in a fatal crash. Adjusted odds ratios of committing an UDA for alcohol alone, THC alone, and their combined effect were computed via logistic regression and adjusted for a number of potential confounders. RESULTS Over the past two decades, the prevalence of THC and alcohol in car drivers involved in a fatal crash has increased approximately five-fold from below 2% in 1991 to above 10% in 2008. Each 0.01 BAC unit increased the odds of an UDA by approximately 9-11%. Drivers who were positive for THC alone had 16% increased odds of an UDA. When alcohol and THC were combined the odds of an UDA increased by approximately 8-10% for each 0.01 BAC unit increase over alcohol or THC alone. CONCLUSION Drivers positive for both agents had greater odds of making an error than drivers positive for either alcohol or cannabis only. Further research is needed to better examine the interaction between cannabis concentration levels, alcohol, and driving. This research would support enforcement agencies and public health educators by highlighting the combined effect of cannabis at low BAC levels.

Mindfulness-based cognitive therapy reduces symptoms of depression in people with a traumatic brain injury: results from a randomized controlled trial.

Objective:We sought to determine if we could reduce symptoms of depression in individuals with a traumatic brain injury using mindfulness-based cognitive therapy. Setting:The study was conducted in a community setting. Participants:We enrolled adults with symptoms of depression after a traumatic brain injury. Design:We conducted a randomized controlled trial; participants were randomized to the 10-week mindfulness-based cognitive therapy intervention arm or to the wait-list control arm. Main Measures:The primary outcome measure was symptoms of depression using the Beck Depression Inventory-II. Results:The parallel group analysis revealed a greater reduction in Beck Depression Inventory-II scores for the intervention group (6.63, n = 38,) than the control group (2.13, n = 38, P = .029). A medium effect size was observed (Cohen d = 0.56). The improvement in Beck Depression Inventory-II scores was maintained at the 3-month follow-up. Conclusion:These results are consistent with those of other researchers that use mindfulness-based cognitive therapy to reduce symptoms of depression and suggest that further work to replicate these findings and improve upon the efficacy of the intervention is warranted.

Alendronate therapy in men with primary hyperparathyroidism.

OBJECTIVE To determine the skeletal effects of alendronate therapy in men with primary hyperparathyroidism (PHPT) in comparison with those in postmenopausal women. METHODS There essentially are no published data on the effects of bisphosphonate therapy in men with PHPT. We previously conducted a double-blind, randomized, single- crossover trial of alendronate, 10 mg daily, in PHPT and reported that alendronate significantly increases bone mineral density (BMD) at 12 months relative to baseline values. That study sample included both women (n = 28) and men (n = 9) and both premenopausal (n = 4) and postmenopausal (n = 24) women. Study subjects were randomly assigned to receive either alendronate or placebo during the first year, and all subjects received alendronate during the second year. Among the men, 3 received alendronate and 6 received placebo during the first year. The current analysis focuses on the skeletal effects of alendronate therapy in the 9 men during their first year of treatment versus the 6 men during their first year while receiving placebo as well as the 24 postmenopausal women during their first year of alendronate therapy. Paired t tests comparing baseline and 12-month data were performed for the 9 treated men and the 6 control subjects; unpaired t tests were used to compare the 9 treated men and the 24 treated women. RESULTS Alendronate therapy for 1 year (n = 9) resulted in a 4.8% increase in BMD at the lumbar spine (P = .1) in comparison with the men who received 1 year of placebo (n = 6). Relative to baseline, men receiving alendronate showed a significant 4.4% gain in BMD at the lumbar spine (P = .009) and a 2.95% gain in total hip BMD (P =.027). A 47% decline in serum levels of bone-specific alkaline phosphatase activity was also noted with alendronate therapy (P = .003). Changes in BMD in the male population were similar to previously reported effects of alendronate therapy in postmenopausal women with PHPT. CONCLUSION Alendronate therapy in men with PHPT is associated with improvements in BMD and reductions in bone turnover. These data, similar to the findings in postmenopausal women with PHPT, suggest that aminobisphosphonates may be of value in providing skeletal protection for men with PHPT. Further study is needed to confirm skeletal protection and fracture efficacy in this population.

Aggressive driving behaviour in young drivers (aged 16 through 25) involved in fatal crashes

INTRODUCTION We wished to determine the extent to which number of passengers, driver age, and sex were associated with aggressive driving actions (ADAs) in young drivers involved in a fatal crash. METHODS We used U.S. fatal-crash data from Fatality Analysis Reporting System (FARS), 1991 -2008. Proxy measures of aggressive driving included ADA presence and speed differential (posted speed limit minus estimated travel speed). We examined the odds of an ADA and speed differential in young drivers (aged 16 to 25) by passenger status. RESULTS Compared to driving alone young drivers (aged 16) had increased odds of an ADA between 14% (OR: 1.14; 95% CI: 1.07; 1.22) and 95% (OR: 1.95; 95% CI: 1.40; 2.74) when accompanied by one and five passengers, respectively. Further, carrying a higher number of passengers was a stronger predictor of speeding in younger drivers. CONCLUSIONS This study supports the use of graduated licensing approaches. Specifically, developing interventions to reduce aggressive driving appear imperative. IMPACT ON INDUSTRY While the results of our study support the use of graduated licensing approaches there is room for improvement. Our study indicates that tackling impaired driving is not sufficient to drastically reduce aggressive driving among the youngest drivers. Further research on young drivers is required to understand the influence of peers and the role of gender on driving behavior. Strategies to reduce aggressive driving behaviors among the youngest drivers may not only prevent crashes during their early driving careers but may also translate into a reduced crash risk over their lifetime.

The Influence of Stimulants on Truck Driver Crash Responsibility in Fatal Crashes

INTRODUCTION Given the monotony and extended driving periods inherent in transport truck driving, drivers might rely on stimulants to sustain attention and combat fatigue. Research indicates that stimulant use improves some cognitive functions but impairs driving ability and is linked to crashes. The research on crash responsibility among stimulant-positive truck drivers is inconclusive due to small sample sizes and a lack of control over confounding variables. The present study investigated the influence of stimulants on unsafe driving actions (UDAs) in fatal crashes contained in the Fatality Analysis Reporting System (FARS) database. METHODS Logistic regression was used to calculate the odds ratio of an UDA (cases committed an UDA; controls did not) by stimulant status (present; absent) while accounting for the influence of confounding variables (age, previous driving record, and other drug use). RESULTS For all truck drivers, we found that 372 truck drivers tested stimulant-positive representing 0.57% of the entire truck driver sample and 3.7% of truck drivers who were actually tested for drug use. Stimulant-positive truck drivers had a greater proportion of driving record infractions and narcotic drug use compared to stimulant-negative truck drivers. The adjusted odds of committing an UDA were 78% greater for truck drivers who were stimulant-positive (OR: 1.78, 95% CI: 1.41-2.26) compared to truck drivers stimulant-negative. CONCLUSION The results suggest stimulants are associated with crash responsibility and warrant further study into their impact on truck drivers.

Associations between psychotic symptoms and dependence in activities of daily living among older adults with Alzheimer's disease.

BACKGROUND Alzheimers disease (AD) is associated with dependence in activities of daily living (ADL). In addition to the cognitive impairment resulting from AD, the presence of psychotic symptoms may further increase this dependence. The objective of this study was to quantify the additional contribution of psychotic symptoms to dependence in ADL. METHOD We analyzed data from 558 individuals with AD referred to a memory clinic. Information on ADL, psychotic symptoms, depression symptoms, and cognition was collected with standardized instruments. RESULTS The frequency of psychotic symptoms was correlated with dependence in ADL (r = -.44, p < .001). The independent contribution of psychotic symptoms to ADL (basic and instrumental) after consideration for cognitive impairment and depression symptoms was assessed with hierarchical regression models. Twenty-five percent of basic ADL variance was explained by cognition; psychotic symptoms accounted for an additional 7% of the variance (b = -0.12, p < .001). Cognitive impairment explained 31% of instrumental ADL variance; psychotic symptoms accounted for an additional 6% (b = -0.21, p < .001). DISCUSSION Psychotic symptoms are associated with dependence in ADL after controlling for cognitive impairment and depression symptoms. Future research should investigate possible causal linkages between psychotic symptoms and dependence in ADL. This may have implications regarding interventions to maintain independent living in people with AD.

Examining the impact of opioid analgesics on crash responsibility in truck drivers involved in fatal crashes

INTRODUCTION Commercial motor vehicle (CMV) drivers, particularly drivers of large trucks continue to be a population of concern regarding traffic safety despite the reduction in large truck crash rates over the past decade. Medication and drug use while driving is one important risk factor for large truck crashes. Work-related exposures, such as vibration, manual handling and poor ergonomics contribute to an increased risk for injuries and chronic conditions and are common reasons for opioid analgesic (OA) use by CMV truck drivers. The objectives of this study were to examine the role of OA use in CMV truck drivers involved in fatal crashes by: (a) generating prevalence estimates of OA use; (b) documenting the relationship between OA use and crash responsibility. METHODS Case-control study using logistic regression to compare Fatality Analysis Reporting System (1993-2008) record of one or more crash-related unsafe driver actions (UDAs--a proxy measure of responsibility) between drivers with a positive drug test and drivers with a negative drug test for OA, controlling for age, other drug use, and driving history. RESULTS The annual prevalence of OA use among all CMV drivers of large trucks involved in fatal crashes did not exceed 0.46% for any year in the study period and mostly ranged between 0.1 and 0.2%. Male truck drivers using OA had greater odds of committing an UDA (OR: 2.80; 95% CI: 1.64; 4.81). Middle-aged users had greater odds than younger or older users. CONCLUSION The results of our study indicate that the presence of OAs is associated with greater odds of committing an UDA. This association may have implications for the commercial transport industry and traffic safety. However, the limited prevalence of OA use is encouraging and further research is needed to address the limitations of the study.