The direct cost burden of 13years of disabling workplace injuries in the U.S. (1998-2010): Findings from the Liberty Mutual Workplace Safety Index.

INTRODUCTION: Although occupational injuries are among the leading causes of death and disability around the world, the burden due to occupational injuries has historically been under-recognized, obscuring the need to address a major public health problem. METHODS: We established the Liberty Mutual Workplace Safety Index (LMWSI) to provide a reliable annual metric of the leading causes of the most serious workplace injuries in the United States based on direct workers compensation (WC) costs. RESULTS: More than $600 billion in direct WC costs were spent on the most disabling compensable non-fatal injuries and illnesses in the United States from 1998 to 2010. The burden in 2010 remained similar to the burden in 1998 in real terms. The categories of overexertion ($13.6B, 2010) and fall on same level ($8.6B, 2010) were consistently ranked 1st and 2nd. PRACTICAL APPLICATION: The LMWSI was created to establish the relative burdens of events leading to work-related injury so they could be better recognized and prioritized. Such a ranking might be used to develop research goals and interventions to reduce the burden of workplace injury in the United States.

Geographic Variation in Early MRI for Acute Work-Related Low Back Pain and Associated Factors.

STUDY DESIGN: Retrospective cohort study using medical claims data. OBJECTIVE: To document the extent of geographic variation in utilization of magnetic resonance imaging (MRI) for working-age patients early in the course of acute, disabling low back pain (LBP); to identify potential factors associated with the most extreme variations. SUMMARY OF BACKGROUND DATA: Although guidelines discourage MRI in acute uncomplicated LBP, this practice is highly prevalent. Geographic variation in radiologic testing is common, and may indicate problems with access or quality of care, yet this has not been studied in working-age patients with LBP (a frequent cause for acute care visits). METHODS: All cases of acute, disabling LBP with onset between 1/1/2002 and 12/31/2007 were selected from a large workers' compensation data source. Detailed information from medical bills was used to identify persons who received early MRI (within 30 days of onset), classify cases by LBP severity, and exclude those with concurrent injuries or diseases, and/or prior LBP disability. Individual predictors included age, gender, job tenure, and industry. State-level predictors included economic, physician supply and practice variables, workers compensation system features, and MRI testing location. Generalized linear mixed models were constructed to evaluate within- and between-state variability, selecting the six highest and six lowest MRI utilization states. RESULTS: State rates of early MRI scanning varied from 6.0% to 58.4%. In the 12 selected most extreme states, non-hospital MRI sites and lower state median income were associated with higher rates of early MRIs, explaining 84% of between-state variation, and 12.5% of all observed variability. Inter-state differences in MRI rates were greatest for lower-severity cases. Higher severity diagnoses were more common in high utilization states. CONCLUSIONS: Between-state inappropriate early MRI variability is largely explained by rate of non-hospital MRI sites and state median income. Potential solutions include efforts to address inappropriate referral patterns based on private MRI facility ownership, and to improve quality of communication with low-income patients. LEVEL OF EVIDENCE: 4.

The cascade of medical services and associated longitudinal costs due to nonadherent magnetic resonance imaging for low back pain.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare type, timing, and longitudinal medical costs incurred after adherent versus nonadherent magnetic resonance imaging (MRI) for work-related low back pain. SUMMARY OF BACKGROUND DATA: Guidelines advise against MRI for acute uncomplicated low back pain, but is an option for persistent radicular pain after a trial of conservative care. Yet, MRI has become frequent and often nonadherent. Few studies have documented the nature and impact of medical services (including type and timing) initiated by nonadherent MRI. METHODS: A longitudinal, workers' compensation administrative data source was accessed to select low back pain claims filed between January 1, 2006 and December 31, 2006. Cases were grouped by MRI timing (early, timely, no MRI) and subgrouped by severity ("less severe," "more severe") (final cohort = 3022). Health care utilization for each subgroup was evaluated at 3, 6, 9, and 12 months post-MRI. Multivariate logistic regression models examined risk of receiving subsequent diagnostic studies and/or treatments, adjusting for pain indicators and demographic covariates. RESULTS: The adjusted relative risks for MRI group cases to receive electromyography, nerve conduction testing, advanced imaging, injections, and surgery within 6 months post-MRI risks in the range from 6.5 (95% CI: 2.20-19.09) to 54.9 (95% CI: 22.12-136.21) times the rate for the referent group (no MRI less severe). The timely and early MRI less severe subgroups had similar adjusted relative risks to receive most services. The early MRI more severe subgroup cases had generally higher adjusted relative risks than timely MRI more severe subgroup cases. Medical costs for both early MRI subgroups were highest and increased the most over time. CONCLUSION: The impact of nonadherent MRI includes a wide variety of expensive and potentially unnecessary services, and occurs relatively soon post-MRI. Study results provide evidence to promote provider and patient conversations to help patients choose care that is based on evidence, free from harm, less costly, and truly necessary. LEVEL OF EVIDENCE: N/A.

Iatrogenic consequences of early magnetic resonance imaging in acute, work-related, disabling low back pain.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine the effect of early (receipt ≤30 d postonset) magnetic resonance imaging (MRI) on disability and medical cost outcomes in patients with acute, disabling, work-related low back pain (LBP) with and without radiculopathy. SUMMARY OF BACKGROUND DATA: Evidence-based guidelines suggest that, except for "red flags," MRI is indicated to evaluate patients with persistent radicular pain, after 1 month of conservative management, who are candidates for surgery or epidural steroid injections. Prior research has suggested an independent iatrogenic effect of nonindicated early MRI, but it had limited clinical information and/or patient populations. METHODS: A nationally representative sample of workers with acute, disabling, occupational LBP was randomly selected, oversampling those with radiculopathy diagnoses (N = 1000). Clinical information from medical reports was used to exclude cases for which early MRI might have been indicated, or MRI occurred more than 30 days postonset (final cohort = 555). Clinical information was also used to categorize cases into "nonspecific LBP" and "radiculopathy" groups and further divided into "early-MRI" and "no-MRI" subgroups. The Cox proportional hazards model examined the association of early MRI with duration of the first episode of disability. Multivariate linear regression models examined the association with medical costs. All models adjusted for demographic and medical severity measures. RESULTS: In our sample, 37% of the nonspecific LBP and 79.9% of the radiculopathy cases received early MRI. The early-MRI groups had similar outcomes regardless of radiculopathy status: much lower rates of going off disability and, on average, $12,948 to $13,816 higher medical costs than the no-MRI groups. Even in a subgroup with relatively minimal disability impact (≤30 d of total lost time post-MRI), medical costs were, on average, $7643 to $8584 higher in the early-MRI groups. CONCLUSION: Early MRI without indication has a strong iatrogenic effect in acute LBP, regardless of radiculopathy status. Providers and patients should be made aware that when early MRI is not indicated, it provides no benefits, and worse outcomes are likely. LEVEL OF EVIDENCE: 3.

Association of disability duration with physical therapy services provided after meniscal surgery in a workers' compensation population.

OBJECTIVE: To examine the association between physical therapy (PT) amount and type (eg, active exercise and passive modalities) received postmeniscectomy with subsequent days of work disability. DESIGN: Historical prospective study. SETTING: Workers' compensation administrative claims data source. PARTICIPANTS: Patients (N=3888) with a new knee injury filed between January 1, 2001, and December 31, 2003, who underwent meniscectomy within 6 months postinjury. INTERVENTIONS: PT services received within 42 days postmeniscectomy. Patients were divided into 9 groups based on PT service amount and type received during the exposure period (no PT, only low active, only high active, only low passive, only high passive, low active/low passive, high active/low passive, low active/high passive, high active/high passive). MAIN OUTCOME MEASURE: Number of disability days post-exposure period and truncated at the end of the 1.5-year outcome period based on lost-time payments. RESULTS: During the exposure period, 32.5% received no PT services, 15.3% had only active, 1.5% had only passive, and 50.8% had a combination of both. After controlling for covariates (including severity indicators and physical job demands), receipt of any passive services was associated significantly with a greater number of disability days, and no significant differences were found for those who received only active PT compared with those receiving no PT. Severity indicators, including opioid use pre- and postsurgery, more disability before surgery, and greater surgery severity, were associated with more disability days, whereas physical job demands were not. CONCLUSIONS: Our results suggest that passive PT services provided postmeniscectomy may be counterproductive to work resumption. In addition, disability duration was shorter or no different for those who received no PT services than for those who received any type of PT services. With better control of confounders in future studies, a beneficial effect of active PT might be found. For the development of rehabilitation guidelines, randomized controlled trials are needed to better understand the effectiveness of active and passive PT services postmeniscectomy.

Relationship of early magnetic resonance imaging for work-related acute low back pain with disability and medical utilization outcomes.

OBJECTIVE: To examine early magnetic resonance imaging (MRI) utilization for workers compensation cases with acute, disabling low back pain and further, to examine low or high propensity to undergo early MRI with disability duration, medical costs, and surgery. METHODS: Two-year follow-up of 3264 cases. Cox regression and generalized linear models were used to examine the association between both early MRI (first 30 days postonset) and propensity of belonging to the early MRI group (estimated by demographic and severity indicators) with outcomes. RESULTS: A total of 21.7% cases had early MRI. After controlling for covariates, cases that had early MRI and simultaneously had a low propensity to undergo early MRI were more likely to have worse outcomes. CONCLUSIONS: The majority of cases had no early MRI indications. Results suggest that iatrogenic effects of early MRI are worse disability and increased medical costs and surgery, unrelated to severity.

Urban-rural differences in work disability following occupational injury: are they related to differences in healthcare utilization?

OBJECTIVE: To investigate urban-rural differences in health care utilization following compensable work-related injury and determine whether differences relate to work disability. METHODS: Analysis of worker's compensation data relating to 4889 people with a bone fracture. Regression analyses were used to test the associations between rurality, work disability, and health care utilization. RESULTS: Place of residence was found to relate to health care utilization and work-disability duration; however, the direction of this relationship depended on the amount of health care used. At lower levels of utilization, more rural residents had less time off; however, as health care usage increased this trend reversed. CONCLUSIONS: The observed interaction between health care utilization, work-disability, and rurality raises important questions regarding causality and implies that people in both urban and rural areas have the potential to benefit from further investigation into health care practices and associated outcomes.

Geographic variation in opioid prescribing for acute, work-related, low back pain and associated factors: a multilevel analysis.

BACKGROUND: Given reports about variation in opioid prescribing, concerns about increasing opioid use and its associated negative consequences make understanding the sources of variability important. The aims of the study were to assess the extent of and factors associated with geographic variation in early opioid prescribing for acute, work-related, low back pain (LBP). METHODS: Cases were selected from workers compensation administrative data filed between January 1, 2002 and December 31, 2003 and included claims from states with more than 40 cases. Early opioid prescribing (one or more prescriptions within first 15 days) was the outcome. Weighted coefficient of variation (wCOV) estimated geographic variation, and multilevel models measured variability controlling for individual and contextual factors. RESULTS: Of the 8,262 claimants, 21.3% received at least one early opioid prescription. Significant between-state variation was found (wCOV = 53%), from 5.7% (Massachusetts) to 52.9% (South Carolina). Seventy-nine percent of the between-state variation was explained by three contextual factors: state household income inequality (prevalence ratio [PR] 1.06, 95% confidence interval [CI] = 1.01, 1.12), number of physicians per capita (PR 0.99, 95% CI = 0.98, 0.99), and workers compensation cost containment effort score (PR 1.12, 95% CI = 1.02, 1.24). Individual-level factors, including severity, explained only a small portion of the geographic variability. CONCLUSION: Geographic variation of early opioid prescribing for acute LBP is important and almost fully explained by state-level contextual factors. The study suggests that clinician and patient interaction and the subsequent decision to use opioids are substantially framed by social conditions and control systems. Am. J. Ind. Med. 52:162-171, 2009. (c) 2008 Wiley-Liss, Inc.

Urban-rural differences in work disability after an occupational injury.

OBJECTIVES: In comparison with their urban counterparts, people living in rural areas have been found to experience higher rates of morbidity and mortality and have inferior health outcomes after illnesses and injuries. The current study sought to determine if this trend extends to work-disability outcomes after work-related injuries. METHODS: This study was a retrospective cohort study using data on workers' compensation claims. Rurality was defined at the postal-code level on the basis of United States 2000 census data. Work disability was measured using the number of full days a person was off work in the 2 years following an injury. Regression analyses were used to test the association between rurality and the duration of work disability after a work-related bone fracture. RESULTS: The claimants with higher rurality experienced less work disability than those with lower rurality. This relationship remained after control for the impact of age, gender, part of body injured, occupation, and industry. CONCLUSIONS: Rurality was found to be related to work disability. However, rather than being associated with more time off after an injury, as could be expected on the basis of past findings, increased rurality was found to be associated with less time off work. The findings suggest that features of rural environments, cultures, and behavioral patterns may facilitate return to work.

Relationship between early opioid prescribing for acute occupational low back pain and disability duration, medical costs, subsequent surgery and late opioid use.

STUDY DESIGN: Retrospective cohort study of workers' compensation (WC) claims with acute disabling low back pain (LBP). OBJECTIVE: To examine the association between early opioid use for acute LBP and outcomes: disability duration, medical costs, "late opioid" use (> or = 5 prescriptions from 30 to 730 days), and surgery in a 2-year period following LBP onset. SUMMARY OF BACKGROUND DATA: Opioid analgesics have become more accepted for acute pain management. However, treatment guidelines recommend limited opioid use for acute LBP management. Little is known about the long-term impact on outcomes of opioid use for acute LBP. METHODS: The sample consisted of 8443 claimants from a large WC database with new-onset, disabling LBP that occurred between January 1, 2002 and December 31, 2003. Based on morphine equivalent amount (MEA) in milligrams received in the first 15 days ("early opioids"), claimants were divided into 5 groups (0, 1-140, 141-225, 226-450, 450+). The associations between early opioids and outcomes were evaluated using multivariate linear and logistic regression models. Covariates included age, gender, job tenure, and low back injury severity. Injury severity was classified using ICD-9 codes. RESULTS: Twenty-one percent of claimants received at least 1 early opioid prescription. After controlling for the covariates, mean disability duration, mean medical costs, and risk of surgery and late opioid use increased monotonically with increasing MEA. Those who received more than 450 mg MEA were, on average, disabled 69 days longer than those who received no early opioids (95% confidence interval [CI], 49.2-88.9). Compared with the lowest MEA group (0 mg opioid), the risk for surgery was 3 times greater (95% CI, 2.4-4.0) and the risk of receiving late opioids was 6 times greater (95% CI, 4.9-7.7) in the highest MEA group. Low back injury severity was a strong predictor of all the outcomes. CONCLUSION: Given the negative association between receipt of early opioids for acute LBP and outcomes, it is suggested that the use of opioids for the management of acute LBP may be counterproductive to recovery.

Survey of acute low back pain management by specialty group and practice experience.

OBJECTIVE: The objective of this study was to explore concurrence with evidence-based management of acute back pain by primary care specialty and years in practice groups. METHODS: Participants randomly selected from five American Medical Association physician groups were surveyed asking their initial care recommendations for case scenarios with and without sciatica. Response differences were compared among groups and with the Agency for Health Research Quality's guideline. RESULTS: Response rate was 25%. Emergency physicians were least likely to order diagnostic studies for both cases but more often made recommendations likely to promote inactivity. Occupational physicians were less likely to order diagnostic studies and more likely choose treatments conducive to increasing activity. The longer physicians were in practice, the less likely they were to follow recommendations. All specialty groups selected more nonevidence-based interventions for the patient with sciatica. General practitioners were least likely to follow the guidelines in either case. CONCLUSIONS: Despite widespread dissemination of acute low back pain guidelines, the study suggests a lack of adherence by certain primary care groups, physicians with more practice experience, and in specific areas of management.

Physicians' initial management of acute low back pain versus evidence-based guidelines. Influence of sciatica.

BACKGROUND: Little information is available on physician characteristics and patient presentations that may influence compliance with evidence-based guidelines for acute low back pain. OBJECTIVE: To assess whether physicians' management decisions are consistent with the Agency for Health Research Quality's guideline and whether responses varied with the presentation of sciatica or by physician characteristics. DESIGN: Cross-sectional study using a mailed survey. PARTICIPANTS: Participants were randomly selected from internal medicine, family practice, general practice, emergency medicine, and occupational medicine specialties. MEASUREMENTS: A questionnaire asked for recommendations for 2 case scenarios, representing patients without and with sciatica, respectively. RESULTS: Seven hundred and twenty surveys were completed (response rate=25%). In cases 1 (without sciatica) and 2 (with sciatica), 26.9% and 4.3% of physicians fully complied with the guideline, respectively. For each year in practice, the odds of guideline noncompliance increased 1.03 times (95% confidence interval [CI]=1.01 to 1.05) for case 1. With occupational medicine as the referent specialty, general practice had the greatest odds of noncompliance (3.60, 95% CI=1.75 to 7.40) in case 1, followed by internal medicine and emergency medicine. Results for case 2 reflected the influence of sciatica with internal medicine having substantially higher odds (vs case 1) and the greatest odds of noncompliance of any specialty (6.93, 95% CI=1.47 to 32.78), followed by family practice and emergency medicine. CONCLUSIONS: A majority of primary care physicians continue to be noncompliant with evidence-based back pain guidelines. Sciatica dramatically influenced clinical decision-making, increasing the extent of noncompliance, particularly for internal medicine and family practice. Physicians' misunderstanding of sciatica's natural history and belief that more intensive initial management is indicated may be factors underlying the observed influence of sciatica.

Outcomes of workers' compensation claimants with low back pain undergoing intradiscal electrothermal therapy.

STUDY DESIGN: Case series. OBJECTIVE: To describe the outcomes of workers' compensation (WC) claimants who have had a lumbar intradiscal electrothermal therapy (IDET) procedure. SUMMARY OF BACKGROUND DATA: IDET was developed as a less invasive treatment alternative to fusion after failure of conservative treatment for discogenic low back pain (LBP). Initial IDET case series from single practices have reported improved pain, function, and return to work outcomes. Little is known about results when performed by a variety of providers or in WC populations. MATERIALS AND METHODS: LBP cases that underwent IDET between December 1, 1998 and February 29, 2000 were identified from WC records. Data sources included hardcopy claim files, administrative medical billing data, and computerized claim file narrative reports. Outcomes included narcotic use 6 months or more after IDET, additional invasive treatment after IDET (low back injections or surgery), and improved work status 24 months after IDET. RESULTS: One hundred forty-two cases from 23 states were identified, with 97 different providers performing the procedure. Mean duration of symptoms before IDET was 26 months. Mean follow-up duration after IDET was 22 months. Ninety-six (68%) of the cases did not meet one or more of the published inclusion criteria. Seventy-eight cases (55%) received at least two narcotic prescriptions 6 months or more after IDET. Fifty-three (37%) had at least one lumbar injection and 32 (23%) had lumbar surgery after IDET. A total of 55 (39%) were working at 24 months after IDET; of these, 28 (20%) were not working and 27 (19%) were working before IDET. Narcotic use after IDET was associated with narcotic use before IDET, the same provider performing discography and IDET (provider self-referral), and positive signs of radiculopathy (C = 0.80). Need for invasive lumbar procedures after IDET were associated with provider self-referral, narcotic use before IDET, and older age (C = 0.73). Continued work absence after IDET was associated with provider self-referral, male gender, litigation, narcotic use before IDET, and older age (C = 0.83). Conformance with published selection criteria for IDET was not associated with provider self-referral or outcomes, nor was duration before IDET associated with outcomes. CONCLUSION: The procedure may be less effective when performed by a variety of providers than suggested by initial case series performed by single providers or practices in work-related LBP cases. Provider self-referral and narcotic use before IDET are significant risk factors for poor outcomes. Randomized controlled trials are needed to determine whether there is a subset of patients with discogenic back pain who derive substantial and sustained benefit from this procedure.

Methodological challenges in studying recurrence of low back pain.

Recurrences of low back pain (LBP) have been shown to be both frequent and costly, with reported recurrence rates ranging from 5 to 82%. Numerous methodological approaches have been developed to identify recurrence but there has been no standardized definition of LBP recurrence or required follow-up time. The objective of this study was to compare the methodological approaches used to analyze LBP recurrence in seminal contributions and to describe the differences in definitions of LBP recurrence and follow-up structure. Twelve seminal articles were identified for review during which four types of LBP recurrence definition and two types of follow-up structure were recognized. Definitional and follow-up differences considerably contributed to variations in computed recurrence rates due either to measurement or other methodological shortcomings, such as loss to follow-up and sick person effect. The results suggest that there is a need to develop a standardized definition of LBP recurrence and a standardized approach to follow-up to allow direct comparisons of published research findings. The use of alternative definitions is also likely to impact analyses of risk factors contributing to LBP recurrence and direct and indirect costs associated with treating LBP.

Disabling occupational injury in the US construction industry, 1996.

In 1996 the US construction industry comprised 5.4% of the annual US employment but accounted for 7.8% of nonfatal occupational injuries and illness and 9.7% of cases involving at least a day away from work. Information in the published literature on the disability arising from construction injuries is limited. The construction claims experience (n = 35,790) of a large workers' compensation insurer with national coverage was examined. The leading types and sources of disabling occupational morbidity in 1996 in the US construction industry were identified. Disability duration was calculated from indemnity payments data using previously published methods. The average disability duration for an injured construction worker was 46 days with a median of 0 days. The most frequently occurring conditions were low back pain (14.8%), foreign body eye injuries (8.5%), and finger lacerations (4.8%). Back pain also accounted for the greatest percentage of construction claim costs (21.3%) and disability days (25.5%). However, the conditions with the longest disability durations were sudden-onset injuries, including fractures of the ankle (median = 55 days), foot (42 days), and wrist (38 days). Same-level and elevated falls were the principal exposures for fractures of the wrist and ankle, whereas elevated falls and struck by incidents accounted for the majority of foot fractures. Manual materials handling activities were most often associated with low back pain disability. The results suggest that these most disabling injuries can be addressed by increasing primary prevention resources in slips and falls and exposures related to injuries of sudden-onset as well as in reducing manual materials handling and other exposures associated with more gradual-onset injuries.

The reduction of chronic, nonspecific low back pain through the control of early morning lumbar flexion: 3-year follow-up.

Three years ago, an 18-month randomized controlled trial of chronic, nonspecific low back pain investigated the effectiveness of instructing subjects to restrict bending activities in the early morning, when the fluid content in the disc is increased. Pain days (as recorded by daily diaries) were reduced 23% in the treatment group, compared to a 2% reduction in the control (sham treatment) group. The purpose of the current follow-up study was to determine whether the results of that trial were maintained during the 3 years following completion of the trial. A questionnaire was mailed to the 60 subjects who completed the original trial. Fifty subjects completed the questionnaire for a response rate of 83%. Thirty-one subjects (62%) continued to restrict bending activities in the early morning, and experienced a further reduction of 10.1 pain days per month (51%) since the completion of the experiment. However, some of the subjects who did not continue to comply also improved. Several possible explanations for the improvement of noncompliant subjects are offered.

Maximal acceptable torques of highly repetitive screw driving, ulnar deviation, and handgrip tasks for 7-hour workdays.

This study represents a continuation of a series of psychophysical studies on repetitive motions of the wrist and hand conducted at the Liberty Mutual Research Center for Safety and Health. The purpose of the study was to quantify maximum acceptable torques of six motions performed on separate days but within the context of the same experiment. The six motions were screw-driving clockwise with a 31-mm handle, a 40-mm handle, and a 39-mm yoke handle; screw-driving counterclockwise with a 31-mm handle; ulnar deviation with a power grip (similar to knife cutting), and a handgrip task (similar to a pliers task). A psychophysical methodology was used in which the subject adjusted the resistance on the handle, and the experimenter manipulated or controlled all other variables. Ten subjects performed the six tasks at repetition rates of 15, 20, and 25 motions per minute. Subjects performed the tasks for 7 hours per day, 5 days per week, for 4 weeks. The subjects were instructed to work as if they were on an incentive basis, getting paid for the amount of work they performed. Symptoms were recorded by the subjects during the last 5 min of each hour. The results revealed that mean maximum acceptable torques ranged from 0.33 to 0.65 Nm for screw driving, 1.08 to 1.13 Nm for ulnar deviation, and 4.80 to 4.85 Nm for the handgrip task. These values represent 14 to 24% (median of 17%) of maximum isometric torque depending on the frequency and motion. A table of maximum acceptable torques and forces of the six motions is presented for application in the field.