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Purpose: This population-based cohort study investigated the association between a lifetime history of a low back injury in a motor vehicle collision (MVC) and future troublesome low back pain. Participants with a history of a low back injury in a motor vehicle collision who had recovered (no or mild low back pain) were compared to those without a history of injury. Current evidence from two cross-sectional and one prospective study suggests that individuals with a history of a low back injury in a MVC are more likely to experience future LBP. There is a need to test this association prospectively in population-based cohorts with adequate control of known confounders., Methods: We formed a cohort of 789 randomly sampled Saskatchewan adults with no or mild LBP. At baseline, participants were asked if they had ever injured their low back in a MVC. Six and 12 months later, participants were asked about the presence of troublesome LBP (grade II-IV) on the Chronic Pain Grade Questionnaire. Multivariable Cox proportional hazards regression analysis was used to estimate the association while controlling for known confounders., Results: The follow-up rate was 74.8% (590/789) at 6 months and 64.5% (509/789) at 12 months. There was a positive crude association between a history of low back injury in a MVC and the development of troublesome LBP over a 12-month period (HRR = 2.76; 95% CI 1.42-5.39). Controlling for arthritis reduced this association (HRR = 2.25; 95% CI 1.11-4.56). Adding confounders that may be on the casual pathway (baseline LBP, depression and HRQoL) to the multivariable model further reduced the association (HRR = 2.20; 95% CI 1.04-4.68)., Conclusion: Our analysis suggests that a history of low back injury in a MVC is a risk factor for developing future troublesome LBP. The consequences of a low back injury in a MVC can predispose individuals to experience recurrent episodes of low back pain.

Purpose: The purpose of this study was to investigate the impact of low back pain (LBP) on future health-related quality of life (HRQoL). Current evidence suggests that individuals with LBP have poorer HRQoL than those without LBP. However, most of the evidence comes from cross-sectional studies where LBP and HRQoL are determined at the same time. One prospective study examined the association between days with LBP and HRQoL but did not account for the intensity of LBP. Therefore, this association needs to be tested in a large prospective population-based sample with a valid measure of LBP and adequate control of known confounders., Methods: We formed a cohort of 1,110 randomly sampled Saskatchewan adults in September 1995. LBP at baseline was measured with the chronic pain questionnaire. The SF-36 questionnaire was used to measure physical and mental HRQoL at 6 months follow-up. Multivariable linear regression was used to estimate the association between graded LBP at baseline and HRQoL at 6 months while controlling for the effects of confounding., Results: The 6-month follow-up rate was 70.7 % (785/1,110). LBP had a dose-response relationship with worsening physical HRQoL at 6 months, after controlling for age, income, arthritis, neck pain, and kidney disorders: grade III-IV LBP (β = -10.23; 95 % CI -12.46, -7.99), grade II LBP (β = -6.72, 95 % CI -8.79, -4.65), and grade I LBP (β = -1.77; 95 % CI -3.18, -0.36). There was no dose-response relationship between LBP and mental HRQoL at 6 months., Conclusions: Low back pain has an impact on future physical HRQoL. Strategies for reducing the effects of LBP on HRQoL should be an important focus for clinicians, researchers, and health policy makers.

Back pain episodes are traditionally regarded as individual events, but this model is currently being challenged in favour of treating back pain as a long-term or lifelong condition. Back pain can be present throughout life, from childhood to older age, and evidence is mounting that pain experience is maintained over long periods: for example, people with pain continue to have it on and off for years, and people without pain do not suddenly develop long-term pain. A number of factors predict back pain presence in epidemiological studies, and these are often present, and predictive, at different life stages. There are also factors present at particular life stages, such as childhood or adolescence, which predict back pain in adulthood. However, there are little published data on long-term pain patterns or predictors over the life course. Such studies could improve our understanding of the development and fluctuations in back pain, and therefore influence treatment approaches., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Study Design: Population-based, retrospective cohort., Objective: To determine whether radiating spinal pain from the low back, mid back, and neck is associated with future use of health-related benefits and their duration as compared with those with nonradiating spinal pain., Summary of Background Data: Studies on the socioeconomic consequences of radiating pain have primarily focused on the low back and to a lesser extent on the neck and mid back. In addition, few studies report on the incidence of health-related benefit use after any radiating spinal pain., Methods: A cohort of 22,952 subjects was formed from the 2002 survey of the Danish Twin Registry. The survey contained information on spinal pain and important confounding factors. Work disability for an 8-year period was determined through data linkage with the Danish Register-Based Evaluation of Marginalization (DREAM) register of government transfer payments. We determined the incidence rate ratio for receipt of sickness benefit and the mean duration of the first and total sickness benefit periods by radiating and nonradiating spinal pain. Relative risks for the occurrence and number of sickness benefit episodes were calculated by radiating spinal pain status., Results: The incidence of sickness benefit was greater for those with radiating spinal pain (89.6 per 1000 person-years [95% confidence interval: 86.0, 93.2]) than those with nonradiating spinal pain (60.4 per 1000 person-years [95% confidence interval: 57.7, 63.1]). However, the duration of time off work, conditional on 1 day or more off work, was the same between those with and without radiating spinal pain., Conclusion: Radiating spinal pain is an important risk factor for future sickness benefit. Radiating spinal pain was not associated with the duration of sickness benefit. These findings were independent of the effects of pain duration at baseline. The results highlight the need for interventions to prevent the onset of work disability, especially for those with radiating pain.

Background: There is evidence for an association between Modic type 1 and pain in patients with low back pain (LBP), but little knowledge about its effect on clinical outcomes., Purpose: (1) To assess the prevalence of Modic changes, (2) to determine if Modic changes influence the clinical course of LBP, and (3) to identify prognostic factors for recovery., Study Design/setting: Prospective clinical cohort study, with a 1-year follow-up. The treatment consisted of brief intervention and instruction in stretching. PATIENT'S SAMPLE: Two hundred and sixty-nine patients with chronic low back pain., Outcome Measures: Socio-demographic variables, education, profession, self-reported measures, degenerative changes on MRI., Methods: Linear growth model and Cox regression analysis., Results: Five percent had a normal MRI, 14 and 50% had Modic 1 and Modic 2 changes. Modic changes were not significant covariates for the clinical course of pain, function or fear avoidance beliefs. Education was a strong prognostic factor for recovery., Conclusions: Modic changes did not influence the clinical course of back pain and were not prognostic factors for recovery. Education was strongly associated with recovery.

Background: Little is known about the role of prior occupational low back injury in future episodes of low back pain and disability in the general population. We conducted a study to determine if a lifetime history of work-related low back injury is associated with prevalent severity-graded low back pain, depressive symptoms, or both, in the general population., Methods: We used data from the Saskatchewan Health and Back Pain Survey - a population-based cross-sectional survey mailed to a random, stratified sample of 2,184 Saskatchewan adults 20 to 69 years of age in 1995. Information on the main independent variable was gathered by asking respondents whether they had ever injured their low back at work. Our outcomes, the 6-month period prevalence of severity-graded low back pain and depressive symptoms during the past week, were measured with valid and reliable questionnaires. The associations between prior work-related low back injury and our outcomes were estimated through multinomial and binary multivariable logistic regression with adjustment for age, gender, and other important covariates., Results: Fifty-five percent of the eligible population participated. Of the 1,086 participants who responded to the question about the main independent variable, 38.0% reported a history of work-related low back injury. A history of work-related low back injury was positively associated with low intensity/low disability low back pain (OR, 3.66; 95%CI, 2.48-5.42), with high intensity/low disability low back pain (OR, 4.03; 95%CI, 2.41-6.76), and with high disability low back pain (OR, 6.76; 95%CI, 3.80-12.01). No association was found between a history of work-related low back injury and depression (OR, 0.85; 95%CI, 0.55-1.30)., Conclusion: Our analysis shows an association between past occupational low back injury and increasing severity of prevalent low back pain, but not depression. These results suggest that past work-related low back injury may be an important risk factor for future episodes of low back pain and disability in the general population.

Study Design: A modified Delphi study conducted with 28 experts in back pain research from 12 countries., Objective: To identify standardized definitions of low back pain that could be consistently used by investigators in prevalence studies to provide comparable data., Summary of Background Data: Differences in the definition of back pain prevalence in population studies lead to heterogeneity in study findings, and limitations or impossibilities in comparing or summarizing prevalence figures from different studies., Methods: Back pain definitions were identified from 51 articles reporting population-based prevalence studies, and dissected into 77 items documenting 7 elements. These items were submitted to a panel of experts for rating and reduction, in 3 rounds (participation: 76%). Preliminary results were presented and discussed during the Amsterdam Forum VIII for Primary Care Research on Low Back Pain, compared with scientific evidence and confirmed and fine-tuned by the panel in a fourth round and the preparation of the current article., Results: Two definitions were agreed on a minimal definition (with 1 question covering site of low back pain, symptoms observed, and time frame of the measure, and a second question on severity of low back pain) and an optimal definition that is made from the minimal definition and add-ons (covering frequency and duration of symptoms, an additional measure of severity, sciatica, and exclusions) that can be adapted to different needs., Conclusion: These definitions provide standards that may improve future comparisons of low back pain prevalence figures by person, place and time characteristics, and offer opportunities for statistical summaries.

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.

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.

Study Design: Historical cohort study., Objectives: We examined the validity of the Isernhagen Work Systems' Evaluation in predicting timely return to work., Summary of Background Data: Functional Capacity Evaluations are used commonly to determine readiness for return to work, yet little is known of their validity., Methods: Workers' compensation claimants undergoing Functional Capacity Evaluations following work-related low back injury were studied. Two cohorts were formed, one on which exploratory analyses were conducted and a second for confirmation. Evaluation indicators were the number of tasks in the protocol rated as failed and performance during the floor-to-waist lift task. The primary outcome investigated was time receiving total temporary disability benefits (as a surrogate of return to work) and a secondary outcome was time until claim closure in the year following Evaluation. Cox proportional-hazards regression was used to determine the prognostic effect of Evaluation crudely and after controlling for potential confounders., Results: Few patients (4%) were found to pass all Evaluation tasks, yet most experienced total temporary disability suspension and claim closure within 1 year following Functional Capacity Evaluations. Better Evaluation performance was related to faster time to suspension of total temporary disability benefits and claim closure after controlling confounding factors, but explained little of the variation in these outcomes (approximately 10%). Performance on the floor-to-waist lift was as predictive as the number of failed tasks in the entire Functional Capacity Evaluations protocol., Conclusions: Better performance on Evaluation was weakly associated with faster recovery; however, the amount of variation explained was small. One task in the Evaluation was as predictive as the entire protocol.

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.

Study Design: A population-based, incidence cohort study was conducted., Objective: To measure the incidence and prognosis for collision-related low back pain before and after a change in the insurance compensation system., Summary of Background Data: Low back pain is a common and costly occupational injury. It also occurs after traffic collisions, but less is known about its frequency and recovery in this setting., Methods: An incidence cohort of 4473 low back pain injury claims was formed between July 1, 1994 and December 31, 1995 in Saskatchewan. On January 1, 1995 the public insurance system changed from a tort system to a no-fault system, eliminating compensation for pain and suffering. The incidence of claims and the time to claim closure were calculated before and after this change. Prognostic models were built using baseline and follow-up data., Results: The 6-month incidence of claims decreased from 256 to 176 per 100,000 after the insurance change. The median time to claim closure dropped from 505 days for tort claims to 210 days and 216 days for claims made during the first and second 6 months of the no-fault period. Improvements in bodily pain and physical functioning and the absence of depressive symptoms were associated with faster claim closure. High pain intensity, female gender, full-time employment, concentration problems, and lawyer involvement early in the claim process delayed claim closure., Conclusions: Low back pain is a common traffic injury with a prolonged recovery. Its incidence and prognosis are affected by multiple factors, including the type of compensation system. Our study suggests that biopsychosocial factors are important in determining prognosis.

Pain coping strategies can be active or passive. Previous studies have examined these strategies separately, however individuals use combinations of both types of coping strategies. We examined the associations between sociodemographic, pain and health-related factors and combinations of active and passive strategies in a general population random sample of 1,131 adults. Individuals reporting neck or low back pain during the past 6 months are the subjects of this report (n = 644). Multinomial logistic regression suggests that disabling pain was highly associated with passive coping regardless of active coping. Lower education was associated with the combination of low levels of active and high levels of passive coping. Individuals with better self-reported general health were less likely to use high levels of passive coping regardless of their active coping. We conclude that high levels of passive coping are strongly associated with disabling pain and that there is no evidence of an association between pain severity and active coping.

Objectives: To determined the association between spinal pain, headache, health, demographic and socio-economic characteristics, and development of depressive symptomatology.Methods: A population-based, random sample of adults was surveyed and followed at 6 and 12 months. Individuals at risk of depression at baseline are the subjects of this article (n = 845). We used Cox proportional hazards models to measure the time-varying effects of demographic, socio-economic, and health status; comorbid medical conditions; spinal pain; and headaches on the development of depression.Results: After adjusting for baseline depressive symptoms and factors associated with nonresponse to follow-up, we found that spinal pain severity, younger age, marital status (separated/divorced/widowed), self-perceived poor health status, and comorbid neurologic and gastro-intestinal disease were associated with onset of a new episode of depression.Conclusions: Important predictors of depressive symptomatology include demographic characteristics, health problems, and pain problems. [Copyright &y& Elsevier]