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1.  JURaSSiC 
Neurology  2013;81(5):448-455.
Objective:
We compared the accuracy of clinicians and a risk score (iScore) to predict observed outcomes following an acute ischemic stroke.
Methods:
The JURaSSiC (Clinician JUdgment vs Risk Score to predict Stroke outComes) study assigned 111 clinicians with expertise in acute stroke care to predict the probability of outcomes of 5 ischemic stroke case scenarios. Cases (n = 1,415) were selected as being representative of the 10 most common clinical presentations from a pool of more than 12,000 stroke patients admitted to 12 stroke centers. The primary outcome was prediction of death or disability (modified Rankin Scale [mRS] ≥3) at discharge within the 95% confidence interval (CI) of observed outcomes. Secondary outcomes included 30-day mortality and death or institutionalization at discharge.
Results:
Clinicians made 1,661 predictions with overall accuracy of 16.9% for death or disability at discharge, 46.9% for 30-day mortality, and 33.1% for death or institutionalization at discharge. In contrast, 90% of the iScore-based estimates were within the 95% CI of observed outcomes. Nearly half (n = 53 of 111; 48%) of participants were unable to accurately predict the probability of the primary outcome in any of the 5 rated cases. Less than 1% (n = 1) provided accurate predictions in 4 of the 5 cases and none accurately predicted all 5 case outcomes. In multivariable analyses, the presence of patient characteristics associated with poor outcomes (mRS ≥3 or death) in previous studies (older age, high NIH Stroke Scale score, and nonlacunar subtype) were associated with more accurate clinician predictions of death at 30 days (odds ratio [OR] 2.40, 95% CI 1.57–3.67) and with a trend for more accurate predictions of death or disability at discharge (OR 1.85, 95% CI 0.99–3.46).
Conclusions:
Clinicians with expertise in stroke performed poorly compared to a validated tool in predicting the outcomes of patients with an acute ischemic stroke. Use of the risk stroke outcome tool may be superior for decision-making following an acute ischemic stroke.
doi:10.1212/WNL.0b013e31829d874e
PMCID: PMC3776534  PMID: 23897872
2.  Judging Whether a Patient is Actually Improving: More Pitfalls from the Science of Human Perception 
Journal of General Internal Medicine  2012;27(9):1195-1199.
Fallible human judgment may lead clinicians to make mistakes when assessing whether a patient is improving following treatment. This article provides a narrative review of selected studies in psychology that describe errors that potentially apply when a physician assesses a patient's response to treatment. Comprehension may be distorted by subjective preconceptions (lack of double blinding). Recall may fail through memory lapses (unwanted forgetfulness) and tacit assumptions (automatic imputation). Evaluations may be further compromised due to the effects of random chance (regression to the mean). Expression may be swayed by unjustified overconfidence following conformist groupthink (group polarization). An awareness of these five pitfalls may help clinicians avoid some errors in medical care when determining whether a patient is improving.
doi:10.1007/s11606-012-2097-2
PMCID: PMC3515001  PMID: 22592355
medical error; fallible reasoning; judgement and decisions; human psychology; patient outcomes; symptom changes
3.  Validity of Physician Billing Claims to Identify Deceased Organ Donors in Large Healthcare Databases 
PLoS ONE  2013;8(8):e70825.
Objective
We evaluated the validity of physician billing claims to identify deceased organ donors in large provincial healthcare databases.
Methods
We conducted a population-based retrospective validation study of all deceased donors in Ontario, Canada from 2006 to 2011 (n = 988). We included all registered deaths during the same period (n = 458,074). Our main outcome measures included sensitivity, specificity, positive predictive value, and negative predictive value of various algorithms consisting of physician billing claims to identify deceased organ donors and organ-specific donors compared to a reference standard of medical chart abstraction.
Results
The best performing algorithm consisted of any one of 10 different physician billing claims. This algorithm had a sensitivity of 75.4% (95% CI: 72.6% to 78.0%) and a positive predictive value of 77.4% (95% CI: 74.7% to 80.0%) for the identification of deceased organ donors. As expected, specificity and negative predictive value were near 100%. The number of organ donors identified by the algorithm each year was similar to the expected value, and this included the pre-validation period (1991 to 2005). Algorithms to identify organ–specific donors performed poorly (e.g. sensitivity ranged from 0% for small intestine to 67% for heart; positive predictive values ranged from 0% for small intestine to 37% for heart).
Interpretation
Primary data abstraction to identify deceased organ donors should be used whenever possible, particularly for the detection of organ-specific donations. The limitations of physician billing claims should be considered whenever they are used.
doi:10.1371/journal.pone.0070825
PMCID: PMC3743842  PMID: 23967114
4.  Drowning and the Influence of Hot Weather 
PLoS ONE  2013;8(8):e71689.
Background
Drowning deaths are devastating and preventable. Public perception does not regard hot weather as a common scenario for drowning deaths. The objective of our study was to test the association between hot weather and drowning risk.
Materials and Methods
We conducted a retrospective case-crossover analysis of all unintentional drowning deaths in Ontario, Canada from 1999 to 2009. Demographic data were obtained from the Office of the Chief Coroner. Weather data were obtained from Environment Canada. We used the pair-matched analytic approach for the case-crossover design to contrast the weather on the date of the drowning with the weather at the same location one week prior (control period).
Results
We identified 1243 drowning deaths. The mean age was 40 years, 82% were male, and most events (71%) occurred in open water. The pair-matched analytic approach indicated that temperatures exceeding 30°C were associated with a 69% increase in the risk of outdoor drowning (OR = 1.69, 95% CI 1.23–2.25, p = 0.001). For indoor drowning, however, temperatures exceeding 30°C were not associated with a statistically significant increase in the risk of drowning (OR = 1.50, 95% CI 0.53–4.21, p = 0.442). Adult men were specifically prone to drown in hot weather (OR 1.67, 95% CI 1.19–2.34, p = 0.003) yet an apparent increase in risk extended to both genders and all age groups.
Conclusion
Contrary to popular belief, hot weather rather than cold stormy weather increases the risk of drowning. An awareness of this risk might encourage greater use of drowning prevention strategies known to save lives.
doi:10.1371/journal.pone.0071689
PMCID: PMC3743751  PMID: 23977112
5.  Modern Medicine Is Neglecting Road Traffic Crashes 
PLoS Medicine  2013;10(6):e1001463.
Don Redelmeier and Barry McLellan admonish the medical community for failure to act on the vast problem of road traffic crashes.
Please see later in the article for the Editors' Summary
doi:10.1371/journal.pmed.1001463
PMCID: PMC3678998  PMID: 23776413
6.  Organ donation after death in Ontario: a population-based cohort study 
Background:
Shortfalls in deceased organ donation lead to shortages of solid organs available for transplantation. We assessed rates of deceased organ donation and compared hospitals that had clinical services for transplant recipients (transplant hospitals) to those that did not (general hospitals).
Methods:
We conducted a population-based cohort analysis involving patients who died from traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage or other catastrophic neurologic conditions in Ontario, Canada, between Apr. 1, 1994, and Mar. 31, 2011. We distinguished between acute care hospitals with and without transplant services. The primary outcome was actual organ donation determined through the physician database for organ procurement procedures.
Results:
Overall, 87 129 patients died from catastrophic neurologic conditions during the study period, of whom 1930 became actual donors. Our primary analysis excluded patients from small hospitals, reducing the total to 79 746 patients, of whom 1898 became actual donors. Patients who died in transplant hospitals had a distribution of demographic characteristics similar to that of patients who died in other large general hospitals. Transplant hospitals had an actual donor rate per 100 deaths that was about 4 times the donor rate at large general hospitals (5.0 v. 1.4, p < 0.001). The relative reduction in donations at general hospitals was accentuated among older patients, persisted among patients who were the most eligible candidates and amounted to about 121 fewer actual donors per year (adjusted odds ratio 0.58, 95% confidence interval 0.36–0.92). Hospital volumes were only weakly correlated with actual organ donation rates.
Interpretation:
Optimizing organ donation requires greater attention to large general hospitals. These hospitals account for most of the potential donors and missed opportunities for deceased organ donation.
doi:10.1503/cmaj.122047
PMCID: PMC3652962  PMID: 23549970
7.  Determining Whether a Patient is Feeling Better: Pitfalls from the Science of Human Perception 
Human perception is fallible and may lead patients to be inaccurate when judging whether their symptoms are improving with treatment. This article provides a narrative review of studies in psychology that describe misconceptions related to a patient's comprehension, recall, evaluation and expression. The specific misconceptions include the power of suggestion (placebo effects), desire for peace-of-mind (cognitive dissonance reduction), inconsistent standards (loss aversion), a flawed sense of time (duration neglect), limited perception (measurement error), declining sensitivity (Weber's law), an eagerness to please (social desirability bias), and subtle affirmation (personal control). An awareness of specific pitfalls might help clinicians avoid some mistakes when providing follow-up and interpreting changes in patient symptoms.
doi:10.1007/s11606-011-1655-3
PMCID: PMC3138972  PMID: 21336670
symptomatic changes; patient follow-up; fallible judgment; medical error; human psychology; eliciting the history
8.  Social benefit payments and acute injury among low-income mothers 
Open Medicine  2012;6(3):e101-e108.
Background
Human error due to risky behaviour is a common and important contributor to acute injury related to poverty. We studied whether social benefit payments mitigate or exacerbate risky behaviours that lead to emergency visits for acute injury among low-income mothers with dependent children.
Methods
We analyzed total emergency department visits throughout Ontario to identify women between 15 and 55 years of age who were mothers of children younger than 18 years, who were living in the lowest socio-economic quintile and who presented with acute injury. We used universal health care databases to evaluate emergency department visits during specific days on which social benefit payments were made (child benefit distribution) relative to visits on control days over a 7-year interval (1 April 2003 to 31 March 2010).
Results
A total of 153 377 emergency department visits met the inclusion criteria. We observed fewer emergencies per day on child benefit payment days than on control days (56.4 v. 60.1, p = 0.008). The difference was primarily explained by lower values among mothers age 35 years or younger (relative reduction 7.29%, 95% confidence interval [CI] 1.69% to 12.88%), those living in urban areas (relative reduction 7.07%, 95% CI 3.05% to 11.10%) and those treated at community hospitals (relative reduction 6.83%, 95% CI 2.46% to 11.19%). No significant differences were observed for the 7 days immediately before or the 7 days immediately after the child benefit payment.
Interpretation
Contrary to political commentary, we found that small reductions in relative poverty mitigated, rather than exacerbated, risky behaviours that contribute to acute injury among low-income mothers with dependent children.
PMCID: PMC3654504  PMID: 23687523
10.  Emergency department visits during an Olympic gold medal television broadcast 
Open Medicine  2011;5(2):e112-e119.
Background
Practice pattern variations are often attributed to physician decision-making with no accounting for patient preferences.
Objective
To test whether a mass media television broadcast unrelated to health was associated with changes in the rate and characteristics of visits for acute emergency care.
Design
Time-series analysis of emergency department visits for any reason.
Subjects
Population-based sample of all patients seeking emergency care in Ontario, Canada.
Measures
The broadcast day was defined as the Olympic men’s gold medal ice hockey game final. The control days were defined as the 6 Sundays before and after the broadcast day.
Results
A total of 99 447 visits occurred over the 7 Sundays, of which 13 990 occurred on the broadcast day. Comparing the broadcast day with control days, we found no significant difference in the hourly rate of visits before the broadcast (544 vs 537, p = 0.41) or after the broadcast (647 vs 639, p = 0.55). In contrast, we observed a significant reduction in hourly rate of visits during the broadcast (647 vs 783, p < 0.001), equal to an absolute decrease of 409 patients, a relative decrease of 17% (95% confidence interval 13–21), or about 136 fewer patients per hour. The relative decrease during the broadcast was particularly large for adult men with low triage severity. The greatest reductions were for patients with abdominal, musculoskeletal or traumatic disorders.
Conclusion
Mass media television broadcasts can influence patient preferences and thereby lead to a decrease in emergency department visits.
PMCID: PMC3148000  PMID: 21915235
11.  On the Psychology of Pharmaceutical Industry Gifts to Physicians 
doi:10.1007/s11606-009-1157-8
PMCID: PMC2811604  PMID: 19894080
12.  Competing risks of mortality with marathons: retrospective analysis 
BMJ : British Medical Journal  2007;335(7633):1275-1277.
Objective To determine from a societal perspective the risk of sudden cardiac death associated with running in an organised marathon compared with the risk of dying from a motor vehicle crash that might otherwise have taken place if the roads had not been closed.
Design Population based retrospective analysis with linked ecological comparisons of sudden death.
Setting Marathons with at least 1000 participants that had two decades of history and were on public roads in the United States, 1975-2004.
Main outcome measures Sudden death attributed to cardiac causes or to motor vehicle trauma.
Results The marathons provided results for 3 292 268 runners on 750 separate days encompassing about 14 million hours of exercise. There were 26 sudden cardiac deaths observed, equivalent to a rate of 0.8 per 100 000 participants (95% confidence interval 0.5 to 1.1). Because of road closure, an estimated 46 motor vehicle fatalities were prevented, equivalent to a relative risk reduction of 35% (95% confidence interval 17% to 49%). The net reduction in sudden death during marathons amounted to a ratio of about 1.8 crash deaths saved for each case of sudden cardiac death observed (95% confidence interval: 0.7 to 3.8). The net reduction in total deaths could not be explained by re-routing traffic to other regions or days and was consistent across different parts of the country, decades of the century, seasons of the year, days of the week, degree of competition, and course difficulty.
Conclusion Organised marathons are not associated with an increase in sudden deaths from a societal perspective, contrary to anecdotal impressions fostered by news media.
doi:10.1136/bmj.39384.551539.25
PMCID: PMC2151171  PMID: 18156224
13.  Road Trauma in Teenage Male Youth with Childhood Disruptive Behavior Disorders: A Population Based Analysis 
PLoS Medicine  2010;7(11):e1000369.
Donald Redelmeier and colleagues conducted a population-based case-control study of 16-19-year-old males hospitalized for road trauma or appendicitis and showed that disruptive behavior disorders explained a significant amount of road trauma in this group.
Background
Teenage male drivers contribute to a large number of serious road crashes despite low rates of driving and excellent physical health. We examined the amount of road trauma involving teenage male youth that might be explained by prior disruptive behavior disorders (attention deficit hyperactivity disorder, conduct disorder, oppositional defiant disorder).
Methods and Findings
We conducted a population-based case-control study of consecutive male youth between age 16 and 19 years hospitalized for road trauma (cases) or appendicitis (controls) in Ontario, Canada over 7 years (April 1, 2002 through March 31, 2009). Using universal health care databases, we identified prior psychiatric diagnoses for each individual during the decade before admission. Overall, a total of 3,421 patients were admitted for road trauma (cases) and 3,812 for appendicitis (controls). A history of disruptive behavior disorders was significantly more frequent among trauma patients than controls (767 of 3,421 versus 664 of 3,812), equal to a one-third increase in the relative risk of road trauma (odds ratio  =  1.37, 95% confidence interval 1.22–1.54, p<0.001). The risk was evident over a range of settings and after adjustment for measured confounders (odds ratio 1.38, 95% confidence interval 1.21–1.56, p<0.001). The risk explained about one-in-20 crashes, was apparent years before the event, extended to those who died, and persisted among those involved as pedestrians.
Conclusions
Disruptive behavior disorders explain a significant amount of road trauma in teenage male youth. Programs addressing such disorders should be considered to prevent injuries.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In the latest World Health Organization (WHO) global burden of disease list, road traffic crashes are currently ranked eighth but are predicted to take fourth place by 2030 (by which time, road traffic deaths are likely to increase by more than 80% in developing countries and to decrease by nearly 30% in industrialized countries.) Every year, road traffic crashes kill an estimated 1.2 million people world-wide and injure or disable a further 20–60 million. Furthermore, the economic consequences of road traffic crashes account for about 2% of the gross national product of the entire global economy.
90% of road traffic deaths occur in developing countries where pedestrians, cyclists, and users of two-wheel vehicles (scooters, motorbikes) are the most vulnerable. In industrialized countries, teenage male drivers are the single most risky demographic group, with an incidence of road traffic crashes of twice that of the population average. Also, male teenagers are sometimes a hazard to other road users and contribute to more fatalities in older pedestrians than older drivers. Furthermore, teenage male drivers involved in serious crashes can have ongoing health care needs but are often resistant to standard road safety advice.
Why Was This Study Done?
Previous studies have suggested that disruptive behavior disorders might contribute to the risk of road traffic crashes in male teenagers but methodological problems with these studies make these results unclear. Given the importance of this topic, authorities have called for more research into the full range of behavioral disorders and relevant populations. This study attempted to avoid the methodological problems of previous studies and to rigorously assess whether disruptive behavior disorders predispose male teenagers to road traffic crashes.
What Did the Researchers Do and Find?
The researchers conducted a 7-year population-based case-control study in Ontario, Canada of consecutive male teenagers aged between 16 and 19 years who were admitted to a hospital due to a road traffic crash, including those who were pedestrians. For the controls, the researchers used consecutive males in the same age range who were admitted to the same hospitals during the same time interval for acute appendicitis (which is common and generally unrelated to traumatic injury). For each participant in the study, the authors used universal health care databases in Canada's single-payer health care system to identify relevant psychiatric diagnoses (attention deficit hyperactivity disorder, conduct disorder, and oppositional defiant disorder) during the decade before admission.
During the study period, 3,421 male teenagers were admitted to hospital as the result of a road traffic crash and 3,812 male teenagers were admitted to hospital for appendicitis. A history of disruptive behavior disorders was significantly more frequent among male teenagers admitted for road traffic crashes than controls (767 of 3,421 versus 664 of 3,812) giving an odds ratio 1.37. This higher risk was still present after the researchers adjusted for possible confounding factors (such as age, social status, and home location) and accounted for about one-in-20 road traffic crashes, including male teenagers who had died and those involved as pedestrians.
What Do These Findings Mean?
The results of this study suggest that disruptive behavior disorders explain a significant amount of road traffic crashes experienced in male teenagers. Overall, attention deficit hyperactivity disorder, conduct disorder, and oppositional defiant disorder are associated with about a one-third increase in the risk of a road traffic crash (which is similar to the relative risk among individuals treated for epilepsy.) As in previous studies in this area, some methodological problems may affect the interpretation of these findings. As this study did not document who was “at fault,” an alternative interpretation might be that behavioral disorders impair a teenager's ability to avoid a mishap initiated by someone else. Most importantly, the observed increase in risk as pedestrians indicates that male teenagers who abstain from driving do not escape the danger of road traffic crashes.
The researchers stress that any increased risk of road traffic crashes associated with disruptive behavior disorders in male teenagers does not justify withholding a driver's license, especially as many such disorders can be effectively treated or, indeed, because it does not address the issue of the increased risk for those teenagers who were pedestrians. Instead, they suggest that disruptive behavior disorders could be considered as contributors to road traffic crashes—analogous to seizure disorders and some other medical diseases. Therefore, greater attention by primary care physicians, psychiatrists, and community health workers might be helpful since interventions can perhaps reduce the risk including medical treatments and avoidance of distractions.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000369.
The World Health Organization has information on road traffic crashes
The US National Institutes of Health has information about behavior disorders in children as well as UK-based Kids Development
The Ontarion Ministry of Transportation has information on annual roadway collisions in Ontario
doi:10.1371/journal.pmed.1000369
PMCID: PMC2981585  PMID: 21125017
14.  The health of homeless immigrants 
Background
This study examined the association between immigrant status and current health in a representative sample of 1,189 homeless people in Toronto, Canada.
Methods
Multivariate regression analyses were performed to examine the relationship between immigrant status and current health status (assessed using the SF-12) among homeless recent immigrants (≤10 years since immigration), non-recent immigrants (>10 years since immigration), and Canadian-born individuals recruited at shelters and meal programs (response rate 73%).
Results
After adjusting for demographic characteristics and lifetime duration of homelessness, recent immigrants were significantly less likely to have chronic conditions (RR 0.7, 95% CI 0.5 to 0.9), mental health problems (OR 0.4, 95% CI 0.2 to 0.7), alcohol problems (OR 0.2, 95% CI 0.1 to 0.5), and drug problems (OR 0.2, 95% CI 0.1 to 0.4) compared to non-recent immigrants and Canadian-born individuals. Recent immigrants were also more likely to have better mental health status (+3.4 points, SE ±1.6) and physical health status (+2.2 points, SE ±1.3) on scales with a mean of 50 and a standard deviation of 10 in the general population.
Conclusion
Homeless recent immigrants are a distinct group who are generally healthier and may have very different service needs compared to other homeless people.
doi:10.1136/jech.2009.088468
PMCID: PMC2773541  PMID: 19654122
homelessness; migration and health
15.  Drug problems among homeless individuals in Toronto, Canada: prevalence, drugs of choice, and relation to health status 
BMC Public Health  2010;10:94.
Background
Drug use is believed to be an important factor contributing to the poor health and increased mortality risk that has been widely observed among homeless individuals. The objective of this study was to determine the prevalence and characteristics of drug use among a representative sample of homeless individuals and to examine the association between drug problems and physical and mental health status.
Methods
Recruitment of 603 single men, 304 single women, and 284 adults with dependent children occurred at homeless shelters and meal programs in Toronto, Canada. Information was collected on demographic characteristics and patterns of drug use. The Addiction Severity Index was used to assess whether participants suffered from drug problems. Associations of drug problems with physical and mental health status (measured by the SF-12 scale) were examined using regression analyses.
Results
Forty percent of the study sample had drug problems in the last 30 days. These individuals were more likely to be single men and less educated than those without drug problems. They were also more likely to have become homeless at a younger age (mean 24.8 vs. 30.9 years) and for a longer duration (mean 4.8 vs. 2.9 years). Marijuana and cocaine were the most frequently used drugs in the past two years (40% and 27%, respectively). Drug problems within the last 30 days were associated with significantly poorer mental health status (-4.9 points, 95% CI -6.5 to -3.2) but not with poorer physical health status (-0.03 points, 95% CI -1.3 to 1.3)).
Conclusions
Drug use is common among homeless individuals in Toronto. Current drug problems are associated with poorer mental health status but not with poorer physical health status.
doi:10.1186/1471-2458-10-94
PMCID: PMC2841106  PMID: 20181248
16.  Motor Vehicle Crashes in Diabetic Patients with Tight Glycemic Control: A Population-based Case Control Analysis 
PLoS Medicine  2009;6(12):e1000192.
Using a population-based case control analysis, Donald Redelmeier and colleagues found that tighter glycemic control, as measured by the HbA1c, is associated with an increased risk of a motor vehicle crash.
Background
Complications from diabetes mellitus can compromise a driver's ability to safely operate a motor vehicle, yet little is known about whether euglycemia predicts normal driving risks among adults with diabetes. We studied the association between glycosylated hemoglobin (HbA1c) and the risk of a motor vehicle crash using a population-based case control analysis.
Methods and Findings
We identified consecutive drivers reported to vehicle licensing authorities between January 1, 2005 to January 1, 2007 who had a diagnosis of diabetes mellitus and a HbA1c documented. The risk of a crash was calculated taking into account potential confounders including blood glucose monitoring, complications, and treatments. A total of 57 patients were involved in a crash and 738 were not involved in a crash. The mean HbA1c was lower for those in a crash than controls (7.4% versus 7.9%, unpaired t-test, p = 0.019), equal to a 26% increase in the relative risk of a crash for each 1% reduction in HbA1c (odds ratio = 1.26, 95% confidence interval 1.03–1.54). The trend was evident across the range of HbA1c values and persisted after adjustment for measured confounders (odds ratio = 1.25, 95% confidence interval 1.02–1.55). The two other significant risk factors for a crash were a history of severe hypoglycemia requiring outside assistance (odds ratio = 4.07, 95% confidence interval 2.35–7.04) and later age at diabetes diagnosis (odds ratio per decade = 1.29, 95% confidence interval 1.07–1.57).
Conclusions
In this selected population, tighter glycemic control, as measured by the HbA1c, is associated with an increased risk of a motor vehicle crash.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Around 8% of the US population has diabetes, a group of diseases in which the body cannot control levels of glucose (sugar) in the blood. It can lead to serious complications and premature death, but suitable treatment can control the disease and lower the risk of complications.
Type 1 diabetes occurs when the body's immune system prevents the production of insulin, the hormone that controls blood glucose. It accounts for 5%–10% of diabetes cases in adults and the vast majority of cases in childhood. Patients with type 1 diabetes need to inject insulin to survive. Type 2 diabetes is associated with older age, obesity, family history of diabetes, lack of physical activity, and race/ethnicity. As obesity rates rise worldwide, it is expected that the prevalence of type 2 diabetes will increase.
Why Was This Study Done?
Some complications of diabetes affect the ability to drive safely. Prolonged periods of high blood sugar levels can damage eyesight and nerves throughout the body, resulting in pain, tingling, and reduction of feeling or muscle control. Over time, some diabetics may become unaware of the early symptoms of an abnormally low blood sugar level (hypoglycemia) that can cause confusion, clumsiness, or fainting. Severe hypoglycemia can result in seizures or a coma.
It is common for driver licensing authorities to require evidence that a diabetic person's condition is well controlled before they issue a driving license. One measure of this is the percentage of hemoglobin in their blood that has joined up with glucose, known as HbA1c. This provides a measure of average blood glucose levels over the previous 8–12 weeks. A lower reading is considered an indicator of good diabetic control, but conversely, a blood glucose level that is too low can cause hypoglycemia. Normal nondiabetic HbA1c is between 3.5% and 5.5%, but 6.5% is considered good for people with diabetes.
In this study the researchers tested whether blood glucose levels, as measured by levels of HbA1c, were statistically associated with the risk of a motor vehicle crash.
What Did the Researchers Do and Find?
The authors studied 795 diabetic adults who had been in contact with the driver licensing authority in Ontario, Canada between January 1, 2005 and January 1, 2007 and for whom HbA1c levels were recorded. HbA1c levels varied between 4.4% and 14.7%.
Of the drivers considered, 57 were involved in a car crash and 738 were not. The authors found that lower HbA1c levels were associated with an increased risk of a motor vehicle crash, even when they took into account other factors such as time since diagnosis, treatment, age, age when diagnosed, and, if taking insulin, age insulin started.
The authors also found that the risk of a crash quadrupled when a driver had a history of severe hypoglycemia that required outside help and that there was an increase in risk when diabetes had first been diagnosed at an older age.
What Do These Findings Mean?
The authors conclude by emphasizing the difficulty in knowing whether someone with diabetes is fit to drive. They suggest that a patient's HbA1c level is neither necessary nor sufficient to determine whether a diabetic person is fit to drive and these results, which agree with some other studies, call into question the current legal framework of the US, UK, Canada, Germany, Holland, and Australia, which single out diabetic drivers for medical review.
The finding that lower HbA1c levels are associated with an increased risk of a crash is surprising, as it suggests that a driver is less safe if they control their diabetes well. However, a statistical link does not prove that one event causes another. Unknown social or medical factors might explain the results. In this case, the authors point out that a major drawback of their study is that it is not randomized and drivers have free will in choosing how tightly to control their diabetes and also how carefully they drive. The authors considered whether time spent driving might explain the results, but discounted this for several reasons. One more plausible explanation is that intensive treatment to attain a lower HbA1c level for better general health raises the risk of hypoglycemic episodes.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000192.
Wikipedia includes an article on diabetes (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The American Diabetes Association publishes information on diabetes in English and Spanish
The American Diabetes Association also publishes information on US states regulation of drivers with diabetes
The World Health Organization of the United Nations Diabetes Programme works to prevent diabetes, minimize complications, and maximize quality of life
doi:10.1371/journal.pmed.1000192
PMCID: PMC2780354  PMID: 19997624
17.  Rainy weather and medical school admission interviews 
Mood can influence behaviour and consumer choice in diverse settings. We found that such cognitive influences extend to candidate admission interviews at a Canadian medical school. We suggest that an awareness of this fallibility might lead to more reasonable medical school admission practices.
doi:10.1503/cmaj.091546
PMCID: PMC2789141  PMID: 19969588
18.  Influenza Morbidity and Mortality in Elderly Patients Receiving Statins: A Cohort Study 
PLoS ONE  2009;4(11):e8087.
Background
Statins possess immunomodulatory properties and have been proposed for reducing morbidity during an influenza pandemic. We sought to evaluate the effect of statins on hospitalizations and deaths related to seasonal influenza outbreaks.
Methodology/Principal Findings
We conducted a population-based cohort study over 10 influenza seasons (1996 to 2006) using linked administrative databases in Ontario, Canada. We identified all adults older than 65 years who had received an influenza vaccination prior to the start of influenza season and distinguished those also prescribed statins (23%) from those not also prescribed statins (77%). Propensity-based matching, which accounted for each individual's likelihood of receiving a statin, yielded a final cohort of 2,240,638 patients, exactly half of whom received statins. Statins were associated with small protective effects against pneumonia hospitalization (odds ratio [OR] 0.92; 95% CI 0.89–0.95), 30-day pneumonia mortality (0.84; 95% CI 0.77–0.91), and all-cause mortality (0.87; 95% CI 0.84–0.89). These protective effects attenuated substantially after multivariate adjustment and when we excluded multiple observations for each individual, declined over time, differed across propensity score quintiles and risk groups, and were unchanged during post-influenza season periods. The main limitations of this study were the observational study design, the non-specific outcomes, and the lack of information on medications while hospitalized.
Conclusions/Significance
Statin use is associated with a statistically significant but minimal protective effect against influenza morbidity that can easily be attributed to residual confounding. Public health officials and clinicians should focus on other measures to reduce morbidity and mortality from the next influenza pandemic.
doi:10.1371/journal.pone.0008087
PMCID: PMC2778952  PMID: 19956645
20.  The effect of traumatic brain injury on the health of homeless people 
Background
We sought to determine the lifetime prevalence of traumatic brain injury and its association with current health conditions in a representative sample of homeless people in Toronto, Ontario.
Methods
We surveyed 601 men and 303 women at homeless shelters and meal programs in 2004–2005 (response rate 76%). We defined traumatic brain injury as any self-reported head injury that left the person dazed, confused, disoriented or unconscious. Injuries resulting in unconsciousness lasting 30 minutes or longer were defined as moderate or severe. We assessed mental health, alcohol and drug problems in the past 30 days using the Addiction Severity Index. Physical and mental health status was assessed using the SF-12 health survey. We examined associations between traumatic brain injury and health conditions.
Results
The lifetime prevalence among homeless participants was 53% for any traumatic brain injury and 12% for moderate or severe traumatic brain injury. For 70% of respondents, their first traumatic brain injury occurred before the onset of homelessness. After adjustment for demographic characteristics and lifetime duration of homelessness, a history of moderate or severe traumatic brain injury was associated with significantly increased likelihood of seizures (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.8 to 5.6), mental health problems (OR 2.5, 95% CI 1.5 to 4.1), drug problems (OR 1.6, 95% CI 1.1 to 2.5), poorer physical health status (–8.3 points, 95% CI –11.1 to –5.5) and poorer mental health status (–6.0 points, 95% CI –8.3 to –3.7).
Interpretation
Prior traumatic brain injury is very common among homeless people and is associated with poorer health.
doi:10.1503/cmaj.080341
PMCID: PMC2553875  PMID: 18838453
21.  Delirium after elective surgery among elderly patients taking statins 
Background
Postoperative delirium after elective surgery is frequent and potentially serious. We sought to determine whether the use of statin medications was associated with a higher risk of postoperative delirium than other medications that do not alter microvascular autoregulation.
Methods
We conducted a retrospective cohort analysis of 284 158 consecutive patients in Ontario aged 65 years and older who were admitted for elective surgery. We identified exposure to statins from outpatient pharmacy records before admission. We identified delirium by examining hospital records after surgery.
Results
About 7% (n = 19 501) of the patients were taking statins. Overall, 3195 patients experienced postoperative delirium; the rate was significantly higher among patients taking statins (14 per 1000) than among those not taking statins (11 per 1000) (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.15–1.47, p < 0.001). The increased risk of postoperative delirium persisted after we adjusted for multiple demographic, medical and surgical factors (OR 1.28, 95% CI 1.12–1.46) and exceeded the increased risk of delirium associated with prolonging surgery by 30 minutes (OR 1.20, 95% CI 1.19– 1.21). The relative risk associated with statin use was somewhat higher among patients who had noncardiac surgery than among those who had cardiac surgery (adjusted OR 1.33, 95% CI 1.16–1.53), and extended to more complicated cases of delirium. We did not observe an increased risk of delirium with 20 other cardiac or noncardiac medications.
Interpretation
The use of statins is associated with an increased risk of postoperative delirium among elderly patients undergoing elective surgery.
doi:10.1503/cmaj.080443
PMCID: PMC2535740  PMID: 18809895
22.  Intensive care outcomes in bone marrow transplant recipients: a population-based cohort analysis 
Critical Care  2008;12(3):R77.
Introduction
Intensive care unit (ICU) admission for bone marrow transplant recipients immediately following transplantation is an ominous event, yet the survival of these patients with subsequent ICU admissions is unknown. Our objective was to determine the long-term outcome of bone marrow transplant recipients admitted to an ICU during subsequent hospitalizations.
Methods
We conducted a population-based cohort analysis of all adult bone marrow transplant recipients who received subsequent ICU care in Ontario, Canada from 1 January 1992 to 31 March 2002. The primary endpoint was mortality at 1 year.
Results
A total of 2,653 patients received bone marrow transplantation; 504 of which received ICU care during a subsequent hospitalization. Patients receiving any major procedure during their ICU stay had higher 1-year mortality than those patients who received no ICU procedure (87% versus 44%, P < 0.0001). Death rates at 1 year were highest for those receiving mechanical ventilation (87%), pulmonary artery catheterization (91%), or hemodialysis (94%). In combination, the strongest independent predictors of death at 1 year were mechanical ventilation (odds ratio, 7.4; 95% confidence interval, 4.8 to 11.4) and hemodialysis (odds ratio, 8.7; 95% confidence interval, 2.1 to 36.7), yet no combination of procedures uniformly predicted 100% mortality.
Conclusion
The prognosis of bone marrow transplant recipients receiving ICU care during subsequent hospitalizations is very poor but should not be considered futile.
doi:10.1186/cc6923
PMCID: PMC2481474  PMID: 18547422
23.  Alcohol Sales and Risk of Serious Assault 
PLoS Medicine  2008;5(5):e104.
Background
Alcohol is a contributing cause of unintentional injuries, such as motor vehicle crashes. Prior research on the association between alcohol use and violent injury was limited to survey-based data, and the inclusion of cases from a single trauma centre, without adequate controls. Beyond these limitations was the inability of prior researchers to comprehensively capture most alcohol sales. In Ontario, most alcohol is sold through retail outlets run by the provincial government, and hospitals are financed under a provincial health care system. We assessed the risk of being hospitalized due to assault in association with retail alcohol sales across Ontario.
Methods and Findings
We performed a population-based case-crossover analysis of all persons aged 13 years and older hospitalized for assault in Ontario from 1 April 2002 to 1 December 2004. On the day prior to each assault case's hospitalization, the volume of alcohol sold at the store in closest proximity to the victim's home was compared to the volume of alcohol sold at the same store 7 d earlier. Conditional logistic regression analysis was used to determine the associated relative risk (RR) of assault per 1,000 l higher daily sales of alcohol. Of the 3,212 persons admitted to hospital for assault, nearly 25% were between the ages of 13 and 20 y, and 83% were male. A total of 1,150 assaults (36%) involved the use of a sharp or blunt weapon, and 1,532 (48%) arose during an unarmed brawl or fight. For every 1,000 l more of alcohol sold per store per day, the relative risk of being hospitalized for assault was 1.13 (95% confidence interval [CI] 1.02–1.26). The risk was accentuated for males (1.18, 95% CI 1.05–1.33), youth aged 13 to 20 y (1.21, 95% CI 0.99–1.46), and those in urban areas (1.19, 95% CI 1.06–1.35).
Conclusions
The risk of being a victim of serious assault increases with alcohol sales, especially among young urban men. Akin to reducing the risk of driving while impaired, consideration should be given to novel methods of preventing alcohol-related violence.
In a population-based case-crossover analysis, Joel Ray and colleagues find that the risk of being a victim of serious assault increases with retail alcohol sales, especially among young urban men.
Editors' Summary
Background.
Alcohol has been produced and consumed around the world since prehistoric times. In the Western world it is now the most commonly consumed psychoactive drug (a substance that changes mood, behavior, and thought processes). The World Health Organization reports that there are 76.3 million persons with alcohol use disorders worldwide. Alcohol consumption is an important factor in unintentional injuries, such as motor vehicle crashes, and in violent criminal behavior. In the United Kingdom, for example, a higher proportion of heavy drinkers than light drinkers cause violent criminal offenses. Other figures suggest that people (in particular, young men) have an increased risk of committing a criminally violent offense within 24 h of drinking alcohol. There is also some evidence that suggests that the victims as well as the perpetrators of assaults have often been drinking recently, possibly because alcohol impairs the victim's ability to judge potentially explosive situations.
Why Was This Study Done?
The researchers wanted to know more about the relationship between alcohol and intentional violence. The recognition of a clear link between driving when impaired by alcohol and motor vehicle crashes has led many countries to introduce public awareness programs that stigmatize drunk driving. If a clear link between alcohol consumption by the people involved in violent crime could also be established, similar programs might reduce alcohol-related assaults. The researchers tested the hypothesis that the risk of being hospitalized due to a violent assault increases when there are increased alcohol sales in the immediate vicinity of the victim's place of residence.
What Did the Researchers Do and Find?
The researchers did their study in Ontario, Canada for three reasons. First, Ontario is Canada's largest province. Second, the province keeps detailed computerized medical records, including records of people hospitalized from being violently assaulted. Third, most alcohol is sold in government-run shops, and the district has the infrastructure to allow daily alcohol sales to be tracked. The researchers identified more than 3,000 people over the age of 13 y who were hospitalized in the province because of a serious assault during a 32-mo period. They compared the volume of alcohol sold at the liquor store nearest to the victim's home the day before the assault with the volume sold at the same store a week earlier (this type of study is called a “case-crossover” study). For every extra 1,000 l of alcohol sold per store per day (a doubling of alcohol sales), the overall risk of being hospitalized for assault increased by 13%. The risk was highest in three subgroups of people: men (18% increased risk), youths aged 13 to 20 y (21% increased risk), and those living in urban areas (19% increased risk). At peak times of alcohol sales, the risk of assault was 41% higher than at times when alcohol sales were lowest.
What Do These Findings Mean?
These findings indicate that the risk of being seriously assaulted increases with the amount of alcohol sold locally the day before the assault and show that the individuals most at risk are young men living in urban areas. Because the study considers only serious assaults and alcohol sold in shops (i.e., not including alcohol sold in bars), it probably underestimates the association between alcohol and assault. It also does not indicate whether the victim or perpetrator of the assault (or both) had been drinking, and its findings may not apply to countries with different drinking habits. Nevertheless, these findings support the idea that the consumption of alcohol contributes to the occurrence of medical injuries from intentional violence. Increasing the price of alcohol or making alcohol harder to obtain might help to reduce the occurrence of alcohol-related assaults. The researchers suggest that a particularly effective approach may be to stigmatize alcohol-related brawling, analogous to the way that driving under the influence of alcohol has been made socially unacceptable.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050104.
This study is further discussed in a PLoS Medicine Perspective by Bennetts and Seabrook
The US National Institute on Alcohol Abuse and Alcoholism provides information on all aspects of alcohol abuse, including an article on alcohol use and violence among young adults
Alcohol-related assault is examined in the British Crime Survey
Alcohol Concern, the UK national agency on alcohol misuse, provides fact sheets on the health impacts of alcohol, young people's drinking, and alcohol and crime
The Canadian Centre for Addiction and Mental Health in Toronto provides information about alcohol addiction (in English and French)
doi:10.1371/journal.pmed.0050104
PMCID: PMC2375945  PMID: 18479181
25.  Mandatory reporting by physicians of patients potentially unfit to drive 
Open Medicine  2008;2(1):e8-e17.
Background
One strategy for the prevention of motor vehicle crashes is physician reporting of medically unfit drivers to vehicle licensing authorities, as mandated by law in Ontario, Canada. We studied drivers involved in life-threatening crashes who required hospital admission to determine how many had previously been seen and reported by a physician in the community.
Methods
We identified consecutive drivers involved in a crash who were admitted to Canada’s largest trauma centre between 30 June 1996 and 30 June 2001 to assess the prevalence of 3 chronic medical conditions reportable to vehicle licensing authorities (alcohol abuse, cardiac disease, and neurological disorders). We then conducted a case series analysis of linked health and transportation databases to determine how many drivers had previously been seen and reported by a physician in the community.
Results
A total of 1,605 injured drivers were identified, of whom 37% had a reportable condition (95% confidence interval [CI] 35–39). Those with a reportable condition had made a total of 20,505 previous visits to 2,332 physicians during the five years before the crash. The majority of patients with a reportable condition (85%, 95% CI 82–88) had seen a physician in the year before the crash but few (3%, 95% CI 2–4) had been reported to licensing authorities. Alcohol abuse was the most common underlying reportable condition (prevalent in 72% of trauma patients with a reportable condition) and the least common reason for a previous report (reported in 2% of those with a reportable condition).
Interpretation
Unsafe drivers often visit physicians and yet are rarely reported to licensing authorities even under mandatory reporting laws for preventive medical reporting.
PMCID: PMC3091591  PMID: 21602950

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