Biomedical subjects

Pierre Côté

Publications and source records attributed to Pierre Côté.

At least 19 recordsLinked to original sources

PubMed2007

Does multidisciplinary rehabilitation benefit whiplash recovery?: results of a population-based incidence cohort study.

STUDY DESIGN: Population-based, incidence cohort. OBJECTIVES: To evaluate a government policy of funding community and hospital-based fitness training and multidisciplinary rehabilitation for whiplash. SUMMARY OF BACKGROUND DATA: Although insurance benefits commonly include rehabilitation for whiplash, its effectiveness is unknown. METHODS: All Saskatchewan adults treated for whiplash (n = 6,021) over a 2-year period were followed up at 6 weeks, 3, 6, 9, and 12 months. Recovery was defined by self-report of improvement. Recovery times were compared between those attending fitness training at health clubs (n = 833), multidisciplinary outpatient rehabilitation (n = 468), and multidisciplinary inpatient rehabilitation (n = 135) to those receiving usual insured individual care. RESULTS: Recovery was 32% slower in those receiving fitness training within 69 days of injury (P = 0.001) and 19% slower when received within 119 days of injury (P = 0.041). Recovery was 50% slower in those receiving outpatient rehabilitation within 119 days of injury (P = 0.001). Attending inpatient rehabilitation did not influence recovery rates during the follow up (P = 0.131). Multivariable adjustment for important prognostic factors did not change these results. CONCLUSIONS: We found no evidence to support the effectiveness of a population-based program of fitness training and multidisciplinary rehabilitation for whiplash. Rehabilitation programs should be tested in randomized trials before being recommended to injured populations.

Adult↗

PubMed2006

Frequency, timing, and course of depressive symptomatology after whiplash.

STUDY DESIGN: Population-based incidence cohort. OBJECTIVE: To report the incidence, timing, and course of depressive symptoms after whiplash. SUMMARY OF BACKGROUND DATA: Evidence is conflicting about the frequency, time of onset, and course of depressive symptoms after whiplash. METHODS: Adults making an insurance claim or seeking health care for traffic-related whiplash were followed by telephone interview at 6 weeks, and 3, 6, 9, and 12 months post-injury. Depressive symptoms were assessed at baseline and at each follow-up. RESULTS: Of the 5,211 subjects reporting no pre-injury mental health problems, 42.3% (95% confidence interval, 40.9-43.6) developed depressive symptoms within 6 weeks of the injury, with subsequent onset in 17.8% (95% confidence interval, 16.5-19.2). Depressive symptoms were recurrent or persistent in 37.6% of those with early post-injury onset. Pre-injury mental health problems increased the risk of later onset depressive symptoms and of a recurrent or persistent course of early onset depressive symptoms. CONCLUSIONS: Depressive symptomatology after whiplash is common, occurs early after the injury, and is often persistent or recurrent. This suggests that, like neck pain and headache, depressed symptomatology is part of the cluster of acute whiplash symptoms. Clinicians should be aware of both physical and psychologic injuries after traffic collisions.

Accidents, Traffic↗

PubMed2006

The role of pain coping strategies in prognosis after whiplash injury: passive coping predicts slowed recovery.

Pain coping strategies are associated with pain severity, psychological distress and physical functioning in populations with persistent pain. However, there is little evidence regarding the relationship between coping styles and recovery from recent musculoskeletal injuries. We performed a large, population-based prospective cohort study of traffic injuries to assess the relationship between pain coping strategies and recovery from whiplash injuries. Subjects were initially assessed within 6 weeks of the injury, with structured telephone interview follow-up at 6 weeks, and 3, 6, 9 and 12 months post-injury. Coping was measured at 6 weeks using the Pain Management Inventory and recovery was assessed at each subsequent follow-up period, using a global self-report question. Multivariable Cox proportional hazards models showed that early use of passive coping strategies was independently associated with slower recovery. Depressive symptomatology (CES-D) was an effect modifier of this relationship. Without depressive symptomatology, those using high levels of passive coping recovered 37% slower than those using low levels of passive coping (HRR=0.63; 95% CI 0.44-0.91). However, in the presence of depressive symptomatology, those using high levels of passive coping recovered 75% more slowly than those who coped less passively (HRR=0.25; 95% CI 0.17-0.39). In other words, those with depressive symptoms but who used few passive coping strategies recovered four times more quickly than those with depressive symptoms who used high levels of passive coping. Active coping showed no independent association with recovery. These findings highlight the importance of early assessment of both coping behaviors and depressive symptomatology.

Adaptation, Psychological↗

PubMed2006

Evaluation of the quality of prognosis studies in systematic reviews.

BACKGROUND: To provide valid assessments of answers to prognostic questions, systematic reviews must appraise the quality of the available evidence. However, no standard quality assessment method is currently available. PURPOSE: To appraise how authors assess the quality of individual studies in systematic reviews about prognosis and to propose recommendations for these quality assessments. DATA SOURCES: English-language publications listed in MEDLINE from 1966 to October 2005 and review of cited references. STUDY SELECTION: 163 systematic reviews about prognosis that included assessments of the quality of studies. DATA EXTRACTION: A total of 882 distinct quality items were extracted from the assessments that were reported in the various reviews. Using an iterative process, 2 independent reviewers grouped the items into 25 domains. The authors then specifically identified domains necessary to assess potential biases of studies and evaluated how often those domains had been addressed in each review. DATA SYNTHESIS: Fourteen of the domains addressed 6 sources of bias related to study participation, study attrition, measurement of prognostic factors, measurement of and controlling for confounding variables, measurement of outcomes, and analysis approaches. Reviews assessed a median of 2 of the 6 potential biases; only 2 (1%) included criteria aimed at appraising all potential sources of bias. Few reviews adequately assessed the impact of confounding (12%), although more than half (59%) appraised the methods used to measure the prognostic factors of interest. LIMITATIONS: Reviews may have been missed by the search or misclassified because of incomplete reporting. Validity and reliability testing of the authors' recommendations are required. CONCLUSIONS: Quality appraisal, a necessary step in systematic reviews, is incomplete in most reviews of prognosis studies. Adequate quality assessment should include judgments about 6 areas of potential study biases. Authors should incorporate these quality assessments into their synthesis of evidence about prognosis.

Bias↗

PubMed2006

Capturing cases in workers' compensation databases: the example of neck pain.

BACKGROUND: There is a need to more accurately enumerate workers with musculoskeletal injuries who make lost-time claims to workers compensation boards. The objective of this study is to develop an approach to more accurately enumerate these workers. METHODS: Lost-time claims to the Ontario Workplace Safety & Insurance Board (WSIB) were reviewed. Using neck pain as an example, nature of injury and part of body codes were identified to classify cases. Claims of a random sample of 434 claimants were reviewed. The proportion of claimants classified as having neck pain was computed. RESULTS: The proportion of claimants classified with soft-tissue injuries to the neck varied from 0.88 for codes including "neck/cervical region," 0.69 for "back region" to 0.05 for those coded as "shoulder/upper arm." CONCLUSIONS: Restricting the enumeration of injuries to specific part of body codes can lead to a gross underestimation of the magnitude of soft-tissue disorders in epidemiological studies using workers' compensation data. The proposed approach leads to more accurate enumeration.

Accidents, Occupational↗

PubMed2006

Early healthcare provider communication with patients and their workplace following a lost-time claim for an occupational musculoskeletal injury.

PROBLEM: One of the key players in the return-to-work (RTW) and work accommodation process is the healthcare provider (HCP). This study examines the association between RTW approximately one month post injury and early, proactive HCP communication with the patient and workplace. METHODS: In this cross-sectional study 187 Ontario workers completed a telephone survey 17-43 days post injury. All had accepted or pending lost-time claims for back, neck or upper extremity occupational musculoskeletal injuries. Logistic regression was used to analyze the effects of three self-reported items "your HCP told you the date you could RTW," "your HCP advised you on how to prevent re-injury or recurrence," "your HCP made contact with your workplace" on self-reported RTW. Fourteen potential confounders were also tested in the model including sex, age, income, education, occupational classification, worksite size, co-morbidity, psycho-physical work demands, pain, job satisfaction, depression, and time from injury to interview. RESULTS: The HCP giving a patient a RTW date (adjusted OR=3.33, 95% CI=1.62-6.87) and giving a patient guidance on how to prevent recurrence and re-injury (adjusted OR=2.71, 95% CI=1.24-5.95) were positively associated with an early RTW. Contact by the HCP with the workplace was associated with RTW, however, this association became weaker upon adjusting for confounding variables (crude OR=2.11, 95% C1=1.09-4.09; adjusted OR=1.72, 95% CI=0.83-3.58). INTERPRETATION: Our study lends support to the HCP playing an active role early in the RTW process, one that includes direct contact with the workplace and proactive communication with the patient.

Adolescent↗

PubMed2005

Incidence and course of low back pain episodes in the general population.

STUDY DESIGN: Population-based, prospective cohort. OBJECTIVES: To estimate incidence and course of severity-graded low back pain (LBP) episodes in adults. SUMMARY OF BACKGROUND DATA: Past studies report variable estimates that do not differentiate LBP severity. METHODS: An incidence cohort of 318 subjects free of LBP and a course cohort of 792 prevalent cases was formed from respondents to a mailed survey. Incident, recurrent, persistent, aggravated, improved, and resolved episodes were defined by the Chronic Pain Questionnaire. The follow-up at 6 and 12 months was 74% and 62%, respectfully. Annual estimates were age and sex standardized. RESULTS: The cumulative incidence was 18.6% (95% confidence interval [CI], 14.2%-23.0%). Most LBP episodes were mild. Only 1.0% (95% CI, 0.0%-2.2%) developed intense and 0.4% (95% CI, 0.0%-1.0%) developed disabling LBP. Resolution occurred in 26.8% (95% CI, 23.7%-30.0%), and 40.2% (95% CI, 36.7%-43.8%) of episodes persisted. The severity of LBP increased for 14.2% (95% CI, 11.5%-16.8%) and improved for 36.1% (95% CI, 29.7%-42.2%). Of those that recovered, 28.7% (95% CI, 21.2%-36.2%)had a recurrence within 6months,and 82.4% of it was mild LBP. Younger subjects were less likely to have persistent LBP (incidence rate ratio, 0.88; 95% CI, 0.80-0.97) and more likely to have resolution (incidence rate ratio, 1.26; 95% CI, 1.02-1.56). CONCLUSIONS: Most new and recurrent LBP episodes are mild. Less than one third of cases resolve annually, and more than 20% recur within 6 months. LBP episodes are more recurrent and persistent in older adults.

Adult↗

PubMed2005

Initial patterns of clinical care and recovery from whiplash injuries: a population-based cohort study.

BACKGROUND: Little is known about the most effective pattern of clinical care for acute whiplash. We designed a cohort study to determine whether patterns of early clinical care (involving visits to general practitioners, chiropractors, or specialists) were associated with different rates of recovery. METHODS: We studied 2486 Saskatchewan adults with whiplash injuries. We defined 8 initial patterns of care that integrated type of provider and number of visits. We used multivariable Cox models to estimate the association between patterns of care and time to recovery while controlling for injury severity and other confounders. RESULTS: There was an independent association between the type and intensity of initial clinical care and time to recovery. We found that patients in the low-utilization general practitioner group had the fastest recovery, even after controlling for injury severity and other confounders. Compared with this group, the high-utilization general practitioner group experienced a 1-year rate of recovery that was 27% slower (adjusted hazard rate ratio [HRR], 0.73; 95% confidence interval [CI], 0.61-0.87); for the high-utilization chiropractic group it was 39% slower (HRR, 0.61; 95% CI, 0.46-0.81); for the high-utilization general practitioner plus chiropractic combined group it was 28% slower (HRR, 0.72; 95% CI, 0.57-0.91); and for those who consulted general practitioners and specialists, it was 31% slower (HRR, 0.69; 95% CI, 0.55-0.87). CONCLUSIONS: The type and intensity of clinical care initiated within the first month after the injury is associated with the rate of recovery from whiplash injuries. Our study does not support the hypothesis that early aggressive care promotes faster recovery.

Adult↗

PubMed2005

Early patterns of care for occupational back pain.

STUDY DESIGN: Cross-sectional analysis. OBJECTIVES: To describe the early health care utilization for occupational back pain. To identify factors associated with health care seeking and provider choice among persons with occupational back pain. SUMMARY OF BACKGROUND DATA: Back pain is the most prevalent work-related injury, yet little is known about patterns of care for occupational back pain. MATERIALS AND METHODS: The sample includes 1104 workers with incident episodes of low back pain. Outcomes measures include whether or not workers received care and the types of providers seen. Predictors of outcomes include demographics, injury severity, history of back pain, occupation, and employer. RESULTS: Eight percent of workers did not receive care in the first 4 to 16 weeks after filing a workers' compensation claim. Injury severity, gender, occupation, and employer were significant predictors of the decision to seek care. Almost 90% of workers who received care were treated by medical physicians, often in combination with physical therapists or chiropractors. Age, occupation, injury severity, and whether the employer or worker chose the initial health care provider were associated with the choice of provider. Employers selected providers for 78% of injured workers who received care. Medical physicians were the providers most often chosen by both employers and workers, but workers were more likely than employers to select chiropractors. CONCLUSIONS: A small but significant number of injured workers do not seek care for their back pain. Medical physicians treat all but a small fraction of the workers who receive care. The decision to seek care and the choice of providers is associated with injury severity, occupation, and employer actions.

Adult↗

PubMed2005

Methods to account for attrition in longitudinal data: do they work? A simulation study.

Attrition threatens the internal validity of cohort studies. Epidemiologists use various imputation and weighting methods to limit bias due to attrition. However, the ability of these methods to correct for attrition bias has not been tested. We simulated a cohort of 300 subjects using 500 computer replications to determine whether regression imputation, individual weighting, or multiple imputation is useful to reduce attrition bias. We compared these results to a complete subject analysis. Our logistic regression model included a binary exposure and two confounders. We generated 10, 25, and 40% attrition through three missing data mechanisms: missing completely at random (MCAR), missing at random (MAR) and missing not at random (MNAR), and used four covariance matrices to vary attrition. We compared true and estimated mean odds ratios (ORs), standard deviations (SDs), and coverage. With data MCAR and MAR for all attrition rates, the complete subject analysis produced results at least as valid as those from the imputation and weighting methods. With data MNAR, no method provided unbiased estimates of the OR at attrition rates of 25 or 40%. When observations are not MAR or MCAR, imputation and weighting methods may not effectively reduce attrition bias.

Bias↗

PubMed2005

Training the next generation of researchers in work disability prevention: the Canadian Work Disability Prevention CIHR Strategic Training Program.

INTRODUCTION: There is a need to create, disseminate, and implement new knowledge in the work disability prevention (WDP) field. Training programs attracting high-quality applicants and taking into account the complexity of this emerging field are urgently needed. METHODS: An advanced training program, funded by the Canadian Institutes of Health Research (CIHR), was developed by 24 mentors affiliated with nine different universities. The main objective of this program is to develop transdisciplinary knowledge, skills, and attitudes regarding WDP. This program has been developed for PhD students or post-doctoral fellows already registered full-time in a Canadian or recognized foreign university whose main interest is WDP, regardless of the health problem. RESULTS: Since its implementation, the program received two successive cohorts of 10 students. They were registered in 13 universities in five countries and trained in nine different disciplines. CONCLUSIONS AND SIGNIFICANCES: Appropriate WDP research may save major societal costs attributable to prolonged work disability. The proposed training program will contribute to developing tomorrow's research workforce.

Attitude of Health Personnel↗

PubMed2005

Prognosis and the identification of workers risking disability: research issues and directions for future research.

INTRODUCTION: Screening procedures based on prognostic data are an important prerequisite for prevention of disability due to low-back pain. This paper reviews the research on prognosis to delineate the most pertinent research challenges, and outlines directions for future research to improve the scientific quality and screening accuracy of prognostic efforts. METHODS: Reviews of prognosis research were examined to identify key methodological and research issues. RESULTS: Certain issues such as sampling procedures, research designs, data analyses, prognostic indicators, and follow-up procedures limit the value of prior studies. Absence of a clear conceptual framework hampers interpretation of findings and moving research questions forward. The recurrent nature of back pain and the need to effectively include the impact of employer actions and the job market were also identified as significant issues. CONCLUSIONS: Future research will be enhanced by addressing conceptual and definitional issues, applying tested and sensible measures, and careful follow-up of the study population.

Actuarial Analysis↗

PubMed2005

Passive coping is a risk factor for disabling neck or low back pain.

BACKGROUND: Despite evidence suggesting that coping is an important concept in the study of pain, its role in predicting the development of disabling pain has not been previously studied. To assess the relationship between coping and the development of disabling pain. METHODS: From a random sample of adults, we formed a cohort of individuals with non-disabling neck and/or low back pain (n=571). Participants were followed 6 and 12 months after the index survey. Coping was measured with the Vanderbilt Pain Management Inventory. The Chronic Pain Questionnaire was used to measure the presence of disabling neck and/or low back pain. We used Cox proportional hazards regression analyses to investigate the role of passive coping in the development of disabling pain while controlling for confounders. RESULTS: Passive coping was a strong, independent risk factor for disabling neck and/or back pain. Those using moderate to high levels of passive coping strategies were at an over five-fold increased risk of developing disabling pain (Moderate: HRR=5.19, 95% CI=1.78-15.1; High: HRR=6.80, 95% CI=2.36-19.6). Active coping was not found to be a significant risk factor for disabling neck and/or back pain. CONCLUSION: Passive coping is a strong and independent predictor of disabling neck and/or back pain. This strong relationship identifies passive coping as a marker for risk of disability and can allow for the identification of individuals at risk and in need of intervention to aid in improving their overall adjustment.

Adaptation, Psychological↗

PubMed2004

Factors associated with a decrease in the prevalence of drug resistance in newly HIV-1 infected individuals in Montreal.

OBJECTIVE: A decrease in the prevalence of drug resistance (DR) has been observed among recently infected (RI) individuals in Montreal. A study of chronically infected (CI) patients, who represent potential HIV-1 transmitters, was carried out in order to ascertain biological factors associated with this trend change. DESIGN AND METHODS: Retrospective analysis of CI patients was performed for the period 1996-2003. Changes in mean viral load and DR prevalence were assessed in CI patients (n = 2328) and compared to those in RI patients (n = 180) living in the same geographic area. RESULTS: A decrease was observed in the prevalence of DR among RI patients, from 13.0% in 1997-2000 to 4.0% in 2001-2003 (P = 0.04). From 1996 to 2000, the mean viral load in the CI patients decreased by 1.34 log10, to remain steady thereafter. The proportion of CI patients who interrupt treatment increased steadily over 1997-2003 from 3.1% to 16.5% (P < 0.0001). Since 1999, when genotyping analysis became available, we have observed a 0.9 log10 decrease in mean viral load among 602 genotyped CI patients harbouring any major mutations. CONCLUSION: The decrease in transmission of DR documented in Montreal since 2000 coincides with the drop in mean viral load observed in CI patients. Factors that contribute to the decrease in viral load include routine access to genotyping and availability of more potent antiretroviral drugs. Plasma viral load seems to represent the main predictor for the transmission of DR.

Adolescent↗

PubMed2004

Assessment of longitudinal changes in HIV-specific effector activity in subjects undergoing untreated primary HIV infection.

BACKGROUND: Despite the failure of HIV-specific cell-mediated immune responses to clear the virus, these cells play a critical role in the control of viral replication throughout HIV infection. OBJECTIVE: To characterize the natural evolution of the HIV-specific immune response in HIV primary infection (PI). METHODS: Untreated individuals, recruited in HIV PI, were monitored for the evolution of HIV-specific immune responses starting in early HIV disease. Longitudinal analysis of changes in the magnitude and breadth of HIV-specific responses to a panel of MHC class I-restricted peptides was performed using the quantitative interferon-gamma ELISPOT assay. RESULTS: Although immune responses were detected in all individuals at all times tested, the pattern of the immune responses differed significantly from that seen in subjects treated in PI. Untreated PI subjects exhibited dramatic changes with time in the frequency of individual HIV peptide-specific T-cell responses. In contrast HIV-specific immunity was stable in subjects treated in early PI or decreased in intensity and breadth in individuals treated later in PI. In untreated subjects the overall magnitude of HIV-specific reactivity persisted over at least 12 months whereas the number of peptides recognized declined. CONCLUSION: Given that a significant relationship existed between the magnitude of the HIV-specific response and viral load, it is likely that these effector cell expansions and contractions are driven by changes in antigen load.

Adolescent↗

PubMed2004

Depression as a risk factor for onset of an episode of troublesome neck and low back pain.

The objective of this study is to determine whether depression is an independent risk factor for onset of an episode of troublesome neck and low back pain. There is growing evidence that pain problems increase the risk of depression. However, the evidence about the role of depression as a risk factor for onset of pain problems is contradictory. This lack of consistency in research findings may be due in part to methodological weaknesses in existing studies, for example, use of an inappropriate study design and inadequate consideration of confounding. A population-based random sample of adults was surveyed and followed at 6 and 12 months. Individuals at risk of troublesome (intense and/or disabling) neck or low back pain are the subjects of this report (n=790). We used Cox proportional hazards models to measure the time-varying effect of depressive symptoms on the onset of troublesome neck and low back pain. Our multivariable analysis considered the possible confounding effects of demographic and socio-economic factors, health status, co-morbid medical conditions and injuries to the neck or low back. We found an independent and robust relationship between depressive symptoms and onset of an episode of pain. In comparison with the lowest quartile of scores (the least depressed), those in the highest quartile of depression scores had a four-fold increased risk of troublesome neck and low back pain (adjusted HRR 3.97; 95% CI 1.81-8.72). Depression is a strong and independent predictor for the onset of an episode of intense and/or disabling neck and low back pain.

Adult↗

PubMed2004

The annual incidence and course of neck pain in the general population: a population-based cohort study.

Although neck pain is a common source of disability, little is known about its incidence and course. We conducted a population-based cohort study of 1100 randomly selected Saskatchewan adults to determine the annual incidence of neck pain and describe its course. Subjects were initially surveyed by mail in September 1995 and followed-up 6 and 12 months later. The age and gender standardized annual incidence of neck pain is 14.6% (95% confidence interval: 11.3, 17.9). Each year, 0.6% (95% confidence interval: 0.0-1.1) of the population develops disabling neck pain. The annual rate of resolution of neck pain is 36.6% (95% confidence interval: 32.7, 40.5) and another 32.7% (95% confidence interval: 25.5, 39.9) report improvement. Among subjects with prevalent neck pain at baseline, 37.3% (95% confidence interval: 33.4, 41.2) report persistent problems and 9.9% (95% confidence interval: 7.4, 12.5) experience an aggravation during follow-up. Finally, 22.8% (95% confidence interval: 16.4, 29.3) of those with prevalent neck pain at baseline report a recurrent episode. Women are more likely than men to develop neck pain (incidence rate ratio=1.67, 95% confidence interval 1.08-2.60); more likely to suffer from persistent neck problems (incidence rate ratio=1.19, 95% confidence interval 1.03-1.38) and less likely to experience resolution (incidence rate ratio=0.75, 95% confidence interval 0.63-0.88). Neck pain is a disabling condition with a course marked by periods of remission and exacerbation. Contrary to prior belief, most individuals with neck pain do not experience complete resolution of their symptoms and disability.

Adult↗

PubMed2004

Loss to follow-up in cohort studies: how much is too much?

Loss to follow-up is problematic in most cohort studies and often leads to bias. Although guidelines suggest acceptable follow-up rates, the authors are unaware of studies that test the validity of these recommendations. The objective of this study was to determine whether the recommended follow-up thresholds of 60-80% are associated with biased effects in cohort studies. A simulation study was conducted using 1000 computer replications of a cohort of 500 observations. The logistic regression model included a binary exposure and three confounders. Varied correlation structures of the data represented various levels of confounding. Differing levels of loss to follow-up were generated through three mechanisms: missing completely at random (MCAR), missing at random (MAR) and missing not at random (MNAR). The authors found no important bias with levels of loss that varied from 5 to 60% when loss to follow-up was related to MCAR or MAR mechanisms. However, when observations were lost to follow-up based on a MNAR mechanism, the authors found seriously biased estimates of the odds ratios with low levels of loss to follow-up. Loss to follow-up in cohort studies rarely occurs randomly. Therefore, when planning a cohort study, one should assume that loss to follow-up is MNAR and attempt to achieve the maximum follow-up rate possible.

Bias↗