Donald Schopflocher

The high risk of stroke immediately after transient ischemic attack A population-based study

Background: The risk of stroke is elevated in the first 48 hours after TIA. Previous prognostic models suggest that diabetes mellitus, age, and clinical symptomatology predict stroke. The authors evaluated the magnitude of risk of stroke and predictors of stroke after TIA in an entire population over time. Methods: Administrative data from four different databases were used to define TIA and stroke for the entire province of Alberta for the fiscal year (April 1999–March 2000). The age-adjusted incidence of TIA was estimated using direct standardization to the 1996 Canadian population. The risk of stroke after a diagnosis of TIA in an Alberta emergency room was defined using a Kaplan-Meier survival function. Cox proportional hazards modeling was used to develop adjusted risk estimates. Risk assessment began 24 hours after presentation and therefore the risk of stroke in the first few hours after TIA is not captured by our approach. Results: TIA was reported among 2,285 patients for an emergency room diagnosed, age-adjusted incidence of 68.2 per 100,000 population (95% CI 65.3 to 70.9). The risk of stroke after TIA was 9.5% (95% CI 8.3 to 10.7) at 90 days and 14.5% (95% CI 12.8 to 16.2) at 1 year. The risk of combined stroke, myocardial infarction, or death was 21.8% (95% CI 20.0 to 23.6) at 1 year. Hypertension, diabetes mellitus, and older age predicted stroke at 1 year but not earlier. Conclusions: Although stroke is common after TIA, the early risk is not predicted by clinical and demographic factors. Validated models to identify which patients require urgent intervention are needed.

Utilization of health services following spinal cord injury: a 6-year follow-up study

Study design: Cohort study with 6-years follow-up.Objective: To describe the utilization of health services by persons with spinal cord injury (SCI) and compare it with that of the general population.Setting: Alberta, Canada.Methods: All persons who sustained an SCI in Alberta between April 1992 and March 1994 were followed from date of injury to 6 years postinjury. Cases were matched (1:5) with controls randomly selected from the general population and matched for age, gender, and region of residence. Administrative data from centralized health care databases were compiled to provide a complete picture of health care use, including hospitalizations, physician contacts, long-term care admissions, home care services, and the occurrence of secondary complications.Results: In all, 233 individuals with SCI and 1165 matched controls were followed for 6 years. Compared with the control group, persons with SCI were rehospitalized 2.6 times more often, spent 3.3 more days in hospital, were 2.7 times more likely to have a physician contact, and required 30 times more hours of home care services. Of those with SCI, 47.6% were treated for a urinary tract infection, 33.8% for pneumonia, 27.5% for depression, and 19.7% for decubitus ulcer.Conclusion: SCI places a heavy burden on the health care system. Persons with SCI have greater rates of contact with the health system compared with the general population. Secondary complications continue to affect persons with SCI long after the acute trauma.

The epidemiology of traumatic spinal cord injury in Alberta, Canada

OBJECTIVES To describe the incidence and pattern of traumatic spinal cord injury and cauda equina injury (SCI) in a geographically defined region of Canada. METHODS The study period was April 1, 1997 to March 31, 2000. Data were gathered from three provincial sources: administrative data from the Alberta Ministry of Health and Wellness, records from the Alberta Trauma Registry, and death certificates from the Office of the Medical Examiner. RESULTS From all three data sources, 450 cases of SCI were identified. Of these, 71 (15.8%) died prior to hospitalization. The annual incidence rate was 52.5/million population (95% CI: 47.7, 57.4). For those who survived to hospital admission, the incidence rate was 44.3/million/year (95% CI: 39.8, 48.7). The incidence rates for males were consistently higher than for females for all age groups. Motor vehicle collisions accounted for 56.4% of injuries, followed by falls (19.1%). The highest incidence of motor vehicle-related SCI occurred to those between 15 and 29 years (60/million/year). Fall-related injuries primarily occurred to those older than 60 years (45/million/year). Rural residents were 2.5 times as likely to be injured as urban residents. CONCLUSION Prevention strategies for SCI should target males of all ages, adolescents and young adults of both sexes, rural residents, motor vehicle collisions, and fall prevention for those older than 60 years.

The prevalence of chronic pain in Canada

BACKGROUND While chronic pain appears to be relatively common, published population prevalence estimates have been highly variable, partly due to differences in the definition of chronic pain and in survey methodologies. OBJECTIVES To estimate the prevalence of chronic pain in Canada using clear case definitions and a validated survey instrument. METHODS A telephone survey was administered to a representative sample of adults from across Canada using the same screening questionnaire that had been used in a recent large, multicountry study conducted in Europe. RESULTS The prevalence of chronic pain prevalence for adults older than 18 years of age was 18.9%. This was comparable with the overall mean reported using identical survey questions and criteria for chronic pain used in the European study. Chronic pain prevalence was greater in older adults, and females had a higher prevalence at older ages compared with males. Approximately one-half of those with chronic pain reported suffering for more than 10 years. Approximately one-third of those reporting chronic pain rated the intensity in the very severe range. The lower back was the most common site of chronic pain, and arthritis was the most frequently named cause. CONCLUSIONS A consensus is developing that there is a high prevalence of chronic pain within adult populations living in industrialized nations. Recent studies have formulated survey questions carefully and have used large samples. Unfortunately, a substantial proportion of Canadian adults continue to live with chronic pain that is longstanding and severe.

The pot calling the kettle black: the extent and type of errors in a computerized immunization registry and by parent report.

BackgroundAccurate classification of children’s immunization status is essential for clinical care, administration and evaluation of immunization programs, and vaccine program research. Computerized immunization registries have been proposed as a valuable alternative to provider paper records or parent report, but there is a need to better understand the challenges associated with their use. This study assessed the accuracy of immunization status classification in an immunization registry as compared to parent report and determined the number and type of errors occurring in both sources.MethodsThis study was a sub-analysis of a larger study which compared the characteristics of children whose immunizations were up to date (UTD) at two years as compared to those not UTD. Children’s immunization status was initially determined from a population-based immunization registry, and then compared to parent report of immunization status, as reported in a postal survey. Discrepancies between the two sources were adjudicated by review of immunization providers’ hard-copy clinic records. Descriptive analyses included calculating proportions and confidence intervals for errors in classification and reporting of the type and frequency of errors.ResultsAmong the 461 survey respondents, there were 60 discrepancies in immunization status. The majority of errors were due to parent report (n = 44), but the registry was not without fault (n = 16). Parents tended to erroneously report their child as UTD, whereas the registry was more likely to wrongly classify children as not UTD. Reasons for registry errors included failure to account for varicella disease history, variable number of doses required due to age at series initiation, and doses administered out of the region.ConclusionsThese results confirm that parent report is often flawed, but also identify that registries are prone to misclassification of immunization status. Immunization program administrators and researchers need to institute measures to identify and reduce misclassification, in order for registries to play an effective role in the control of vaccine-preventable disease.

A comparative approach to identify unsafe older drivers

The identification of unsafe older drivers is a current and important challenge. In the present research, a comparative approach was used in which the on road driving errors and expert evaluations of older drivers with clinically significant declines in mental abilities (N = 155) were compared to the errors and evaluations of a normal elderly control group (N = 68) and a normal younger control group (N = 30). The results indicate that the conventional criteria used in North America for licensing new drivers is inappropriate for license removal in experienced drivers. The results also indicate that hazardous errors were the single best indicator of membership in the group of older drivers with clinical impairment. This group also differs from the two normal control groups on turn positioning errors, minor positioning errors and overcautiousness. All groups differ from each other on scanning errors. A regression analysis further indicated that the five driving errors listed above accounted for over 57% of the variance associated with global ratings provided by expert driving instructors.

A population-based survey of back pain beliefs in Canada.

Study Design. Population-based survey. Objectives. To assess the back pain beliefs in 2 provinces in Canada to inform a population-based educational campaign. Summary of Background Data. Beliefs, attitudes, and recovery expectations appear to influence recovery from back pain, yet prevailing public opinions about the condition have been little studied. Methods. Telephone surveys were conducted with 2400 adults in 2 Canadian provinces. Surveys included the Back Beliefs Questionnaire, and additional questions concerning age, gender, recent and lifetime back pain, coping strategies for back pain, and awareness and persuasiveness of media information concerning back pain. Results. A high prevalence of back pain was reported, with a lifetime prevalence of 83.8%, and 1-week prevalence of 34.2%. Generally, a pessimistic view of back pain was held. Most agreed that back pain makes everything in life worse, will eventually stop one from working, and will become progressively worse with age. Mixed opinions were observed regarding the importance of rest and staying active. A significant minority (12.3%) reported taking time off from work for their last back pain episode. Those individuals taking time off from work held more negative back pain beliefs, including the belief that back pain should be rested until it gets better. Conclusions. Public back pain beliefs in the 2 Canadian provinces sampled are not in harmony with current scientific evidence for this highly prevalent condition. Given the mismatch between public beliefs and current evidence, strategies for reeducating the public are needed.

Depression following Traumatic Spinal Cord Injury

Objectives: To describe the epidemiology of depression following traumatic spinal cord injury (SCI) and identify risk factors associated with depression. Methods: This population-based cohort study followed individuals from date of SCI to 6 years after injury. Administrative data from a Canadian province with a universal publicly funded health care system and centralized databases were used. A Cox proportional hazards model was developed to identify risk factors. Results: Of 201 patients with SCI, 58 (28.9%) were treated for depression. Individuals at highest risk were those with a pre-injury history of depression [hazard rate ratio (HRR) 1.6; 95% CI: 1.1–2.3], a history of substance abuse (HRR 1.6; 95% CI: 1.2–2.3) or permanent neurological deficit (HRR 1.6; 95% CI: 1.2–2.1). Conclusion: Depression occurs commonly and early in persons who sustain an SCI. Both patient and injury factors are associated with the development of depression. These should be used to target patients for mental health assessment and services during initial hospitalization and following discharge into the community.

Event Clusters: An Organization of Personal Events in Autobiographical Memory

The present study employed a method called event cuing to investigate the organization of autobiographical memory. The unique feature of this method is the use of event descriptions as retrieval cues. Participants first recalled a set of personal events. Next, they responded to each of these cuing events by retrieving a second related personal event (the cued event). Subsequently, relations between cued and cuing events were coded by the participants, and all events were dated and rated for importance. Results indicate that memorable personal events, regardless of age or importance, are often embedded in event clusters; that events organized by these clusters, like episodes in a story, are often causally related, temporally proximate, and similar in content; and that narrative processes may not be necessary for the formation of event clusters, though subsequent narration may affect their contents and structure.

Instigation of Attribution Processes by Attributional Questions

Subjects received help from a confederate that either was or was not situationally facilitated. Half of the subjects then rated the confederates prosocial dispositional qualities, while the other half did not. Subsequent ratings of the confed- erate revealed attributional mediation of perceived attractive- ness only for subjects who had been asked attribution questions.