Association between workers' compensation and outcome following multidisciplinary treatment for chronic pain: roles of mediators and moderators

[Multimodal pain therapy. Current situation]

A multidisciplinary approach for the management of patients with chronic pain is now well-established in many countries, especially in situations involving a complex disease process in the sense of a biopsychosocial model. Both the efficacy and cost-effectiveness of multidisciplinary pain treatment programs and their superiority compared to unimodal therapy has been documented in a number of studies, reviews and meta-analyses, in particular for patients suffering from chronic low back pain. Nevertheless, there are still major shortcomings concerning the definition of multimodal and multidisciplinary treatment and the quality of structures and processes, compared for example to the standards defined by the German Pain Society (Deutsche Schmerzgesellschaft). Furthermore, there is still no consensus on specific therapeutic approaches, the differentiation between responders and non-responders as well as on the tools required for measurement. All these questions will have to be answered by concerted efforts in a multicenter setting.

Is Compensation Bad for your Back?

A series of studies has tested the hypothesis that individuals with chronic pain (especially low back pain) who are receiving compensation respond less satisfactorily to treatment and rehabilitation than those not receiving it, and that symptoms and disability are reinforced and maintained by financial reward. Some examples of evidence for such ‘compensation neurosis’ are reviewed. The impact of socio-economic status, employment and litigation need also to be taken into account. The best response to individuals with chronic pain who are receiving compensation may not be the obvious punitive one of lowering or ceasing benefits. Rather, a compensation system minimising litigation and emphasising co-ordinated rehabilitation is advocated. The author challenges a common clinical — and political — bias against the so-called ‘compensation patient’.

CONCURRENT VALIDITY OF PATIENT RATING SCALES IN ASSESSMENT OF OUTCOME AFTER ROTATOR CUFF REPAIR

The purpose of this study was to compare the concurrent validity of four questionnaires in the assessment of outcome after rotator cuff repair. Sixty-two patients, who were at least two years post-rotator-cuff repair, completed three upper extremity scales: the Western Ontario Rotator Cuff (WORC) index, the Disabilities of the Arm, Shoulder and Hand (DASH) and the Simple Shoulder Test (SST), and a measure of general health status (SF-36). Internal and external rotation ranges of motion and isometric strength were measured. Pearson correlations were used to evaluate the construct whereby scores should be related to the severity of measured impairments. One-way ANOVA was used to determine the ability of the questionnaires to discriminate between groups expected to have different outcomes based on measured impairment or worker's compensation status. The upper extremity questionnaires demonstrated similar response distributions and were highly correlated (0.88 < r < 0.91). The response distribution of the SF-36 was different from the other scales and its correlation with them was moderate (0.58 < r < 0.75). The upper extremity measures demonstrated better correlations with measured impairments (0.18 < r < 0.56) than the SF-36 (0 < r < 0.40). All the questionnaires were able to discriminate between levels of impairment and worker's compensation status. This study supported the validity of upper extremity scales to measure cuff-related disability and suggests that the use of both specific and general health measures provides a more comprehensive evaluation of patient outcome.

Empowerment of disability benefit claimants through an interactive website: design of a randomized controlled trial

BACKGROUND

Individuals claiming a disability benefit after long-term sickness absence, have to undergo medical disability assessments. These assessments, often carried out by specialized physicians, can be complicated by wrong expectations or defensive attitudes of disability benefit claimants. It is hypothesized that empowerment of these claimants will enhance the physician-patient relationship by shifting claimants from a passive role to a more active and constructive role during disability assessments. Furthermore, empowerment of claimants may lead to a more realistic expectation and acceptance of the assessment outcome among claimants and may lead to a more accurate assessment by the physician.

METHODS/DESIGN

In a two-armed randomized controlled trial (RCT), 230 claimants will be randomized to either the intervention or control group. For the intervention group, an interactive website was designed http://www.wiagesprek.nl using an Intervention Mapping procedure. This website was tested during a pilot study among 51 claimants. The final version of the website consists of five interactive modules, in which claimants will be prepared and empowered step-by-step, prior to their upcoming disability assessment. Other website components are a forum, a personal health record, a personal diary, and information on disability assessment procedures, return to work, and coping with disease and work disability. Subjects from the control group will be directed to a website with commonly available information only. Approximately two weeks prior to their disability assessment, disability claimants will be recruited through the Dutch Workers Insurance Authority (UWV). Outcomes will be assessed at five occasions: directly after recruitment (baseline), prior to disability assessment, directly after disability assessment as well as 6 and 16 weeks after the assessment. The study's primary outcome is empowerment, measured with the Vrijbaan questionnaire. Secondary outcomes include claimants' satisfaction, perceived justice, coping strategy, and knowledge. A process evaluation will also be conducted.

DISCUSSION

This study evaluates the effectiveness of an interactive website aimed at empowerment of disability claimants. It is hypothesized that by increasing empowerment, the physician-patient relationship may be enhanced and claimants' satisfaction and perceived justice can be improved. Results are expected in 2010.

TRIAL REGISTRATION

NTR-1414.

Cognitive behavioural therapy increases re-employment of job seeking worker's compensation clients

INTRODUCTION

The aim of this study was to determine whether cognitive behavioural therapy (CBT) would enhance employment outcomes in worker's compensation clients who were seeking employment.

METHODS

Participants were randomly assigned to a standard job search assistance group that met for 4 hours/week for four weeks, or to a group that received standard job search assistance for 4 hours/week for the first two weeks and CBT for 4 hours/week for the next two weeks. Depression, Anxiety and Stress scores were measured prior to and on completion of the intervention, and employment outcomes were assessed at four- and ten-week follow-up.

RESULTS

Affective states decreased and employment was found more rapidly after CBT than after standard job search assistance.

CONCLUSION

These findings indicate that CBT has a useful role in the rehabilitation of people on worker's compensation who are seeking employment.

Medical history and chronic pain

OBJECTIVE

Can either a history of previous similar injury, including recurrence of injury, or an individual's symptoms, including time off work, predict chronic pain and/or chronic pain disability?

METHODOLOGY

The literature search identified one systematic review and six observational studies (5 low back pain and 1 chronic shoulder pain) to provide evidence about these questions.

RESULTS

Only one study evaluated subjects before a painful event. Other studies evaluated subjects over a range of time from onset of pain, including some selected for clinic treatment. This variability as well as the use of different outcome measures without blinding limited the quality of the evidence.

CONCLUSIONS

The studies provide moderate evidence (level 2) that a history of previous similar pain predicts subsequent reports of pain and limited evidence (level 3) that a history of similar pain predicts poorer outcomes after recurrent injury. The studies also provide moderate evidence (level 2) that longer duration of pain predicts the occurrence of subsequent reports of pain and limited evidence (level 3) that longer time off work before treatment predicts poorer activity and poorer participation outcomes after recurrent injury.

Physical symptoms and signs and chronic pain

OBJECTIVE

Do physical findings that are used to indicate location and extent of tissue damage and a measure of the severity of initial pain predict subsequent reports of pain and of disability?

METHODOLOGY

A standardized literature search identified one systematic review and 12 observational studies (9 low back pain, 2 neck pain, and 1 carpal tunnel syndrome) to provide evidence about these questions.

RESULTS

Most studies were of specific populations. These studies were useful studies of predictors, but they have limited generalizability. Exclusions and loss of subjects at follow-up in some studies also limited generalizability. Conclusions were made cautiously, because some factors with statistical correlations with chronic pain were not plausible predictors.

CONCLUSIONS

The studies provide moderate evidence (level 2) that reports of the intensity of pain in acute musculoskeletal injury predict subsequent reports of pain. There is limited evidence (level 3) that the location and extent of injury predict reports of pain and poor functional activity outcomes. There is moderate evidence (level 2) that physical symptoms and signs cannot be considered individual predictors of chronic pain disability as measured by participation outcomes. Instead, in the transition from subacute to chronic pain disability, functional disability and psychological distress play a more important role than pain intensity.

Compensation and chronic pain

BACKGROUND

The literature contains many different viewpoints on the impact of compensation on recovery from chronic pain.

OBJECTIVE

What is the role of compensation in chronic pain and/or chronic pain disability?

METHODOLOGY

The literature search identified 11 observational studies to provide evidence about this question.

RESULTS

There is a paucity of high-quality data on the subject of the impact of compensation on chronic pain. This subject was reviewed under the headings of (1) injury claim rate and duration; (2) recovery; and (3) rehabilitation treatment programs. The studies were of subjects with musculoskeletal pain, mainly low back pain.

CONCLUSIONS

Filing a compensation claim for costs, retaining a lawyer, or higher pain intensities were limited predictors of longer claims (level 3). As the ratio of compensation to preinjury wage increases, there is moderate evidence (level 2) that the duration of the claim increases and that disability is more likely. Compensation status, particularly combined with higher pain intensities, is associated with poorer prognosis after rehabilitation treatment programs (level 3).

Outcomes of pain center treatment in Washington State workers' compensation

BACKGROUND

Injured workers with chronic pain who have failed conventional therapies often receive treatment at pain centers. This study evaluated the effect of pain center treatment on time loss status of Washington State injured workers. The primary hypothesis was that treatment at a pain center would lead to a reduction in the probability of a worker's receiving time loss benefits at a 2-year follow-up.

METHODS

A population-based retrospective cohort study was performed on 2,032 Washington State workers' compensation patients who underwent pain center evaluations. Subjects who received pain center treatment were compared to those who were evaluated but not treated with respect to time loss status at 2-year follow-up.

RESULTS

Univariate analysis revealed that at 2-year follow-up, 35% of treated subjects were receiving time loss payments vs. 40% of evaluated only subjects (P < 0.05). Subjects who were younger, female, and less chronic were more likely to undergo pain center treatment and were less likely to be on time loss at 2-year follow-up. In multivariate analyses, which statistically controlled baseline differences between the two groups, there was no difference between treated subjects and evaluated only subjects.

CONCLUSIONS

There was no evidence that pain center treatment alters 2-year time loss status of already disabled workers.

Prediction of "intent", "discrepancy with intent", and "discrepancy with nonintent" for the patient with chronic pain to return to work after treatment at a pain facility

OBJECTIVE

We previously determined that "intent" to return to work post pain facility treatment is the strongest predictor for actual return to work. The purposes of the present study were the following: to identify variables predicting "intent"; to predict membership in the "discrepant with intent" group [those chronic pain patients (CPPs) who do intend to return to work but do not]; and to predict membership in the "discrepant with nonintent" group (those CPPs who do not intend to return to work but do).

DESIGN

A total of 128 CPPs completed a series of rating scales and yes/no questions relating to their preinjury job perceptions and a question relating to "intent" to return to the same type of preinjury job post-pain facility treatment. These CPPs were part of a grant study for prediction of return to work, and therefore their work status was determined at 1, 3, 6, 12, 18, 24, and 30 months posttreatment. Preinjury job perceptions and other demographic variables were utilized using stepwise discriminant analysis to identify variables predicting "intent" and predicting membership in the "discrepant with intent" and "discrepant with nonintent" groups.

SETTING

Pain facility (multidisciplinary pain center).

PATIENTS

Consecutive low back pain CPPs, mean age 41.66+/-9.54 years, with the most frequent highest educational status being high school completion (54.7%) and 60.2% being worker compensation CPPs.

RESULTS

"Intent" was predicted by (in decreasing order of probability) postinjury job availability variables, job characteristic variables, and a litigation variable. "Discrepant with intent" was predicted by (in decreasing order of probability) for the 1-month follow-up time point, postinjury job availability variables, pain variables, a litigation variable, and a function perception variable, and for the final follow-up time point, pain variables only. "Discrepant with nonintent" was predicted by (in order of decreasing probability) for the 1-month follow-up time point, a job availability variable, a demographic variable, and a functional perception variable, and for the final follow-up time point a pain variable and a job availability variable. The percentage of CPPs correctly classified by each of these analyses was as follows: "intent" 81.25%, "discrepant with intent" 87.01% (at 1-month follow-up) and 74.03% (final follow-up), "discrepant with nonintent" 92.16% (at 1-month follow-up) and 75.00% (final follow-up).

CONCLUSIONS

CPPs intentions of returning to their preinjury jobs are mainly determined by job availability and job characteristic variables but surprisingly not by pain variables. However, the results with "discrepant with intent" and "discrepant with nonintent" groups indicate that actual return to work is determined by an interaction between job availability variables and pain variables with pain variables predominating for long-term outcome.

Predictors of rate of return to work after surgery for carpal tunnel syndrome

OBJECTIVE

To evaluate the impact of patient demographics, clinical features, and job-related factors on the time until return to work after carpal tunnel release surgery.

METHODS

We employed a cross-sectional community-based study of 59 patients who had undergone carpal tunnel release surgery. Sociodemographic, clinical, and job-related characteristics and time to return to work were obtained by interview and from medical records. Exposure to ergonomic risk was derived from an independently validated job matrix. Time to return to work after surgery was analyzed by survival techniques.

RESULTS

Median time to return to work was 5 weeks. After adjustment, the relative rate (RR) of return to work per week after surgery was most strongly decreased by the receipt of workers' compensation, RR 0.2 (95% confidence interval [CI] 0.1-0.5), and by the exposure to bending and twisting of the hand prior to surgery, RR 0.7 (95% CI 0.5-0.9) per hour. Female gender was another predictor of decreased return to work, RR 0.5 (95% CI 0.3-0.8).

CONCLUSIONS

Patients receiving workers' compensation, those exposed to higher levels of bending and twisting of their hands and wrists, and women were slower to return to work after carpal tunnel release surgery.

Goal setting as a predictor of return to work in a population of chronic musculoskeletal pain patients

To assess prospectively the association between personal attributes, vocational factors, and the return to work outcome for patients with chronic, nonmalignant, musculoskeletal pain, we assessed return to work (RTW) motivation though an open-format listing of treatment goals in 59 chronic pain patients admitted to a university pain management program. Patients were then followed (average of 17.9 months) in the posttreatment period to determine whether they had in fact returned to employment. Results indicated that a number of pretreatment factors predicted future employment status in this patient population. Age, marital status, education and decreased length of unemployment were predictive of RTW outcome. Overall, RTW goal was the single best predictor of return to work outcome. In contrast, increased number of premorbid jobs, compensation status, patient's race and sex were not predictive. The present study suggests that the assessment of an individual's motivation as defined by goal-setting may be a key factor in predicting a favorable outcome in this typically refractory population of patients.

The effect of compensation involvement on the reporting of pain and disability by patients referred for rehabilitation of chronic low back pain

STUDY DESIGN

In this prospective, observational, cohort study of 192 individuals with chronic low back pain, the group of individuals was divided based on compensation involvement, and their presentation pain and disability, treatment recommendations, and compliance were compared. For 85 of these individuals who completed a spine rehabilitation program, their pain and disability at 3 and 12 months were compared.

OBJECTIVES

To test the theory that individuals with compensation involvement presented with greater pain and disability and would report less change of pain and disability after rehabilitation efforts.

BACKGROUND

Previous studies have produced conflicting results concerning this issue.

METHODS

Individuals were recruited as consecutive patients referred for consultation at a spine rehabilitation center. Pain, depression, and disability were assessed using self-report questionnaires at evaluation and at 3 and 12 months. Rehabilitation services consisted of aggressive, quota-based exercises aimed at correcting impairments in flexibility, strength, endurance, and lifting capacity, identified through quantification of back function. Multifactoral analysis of variance models were used to control for baseline differences between compensation and noncompensation patients during analysis of target variables.

RESULTS

The compensation group included 96 patients; these patients reported more pain, depression, and disability than the 96 patients without compensation involvement. These differences persisted when baseline differences were controlled for with multifactoral analysis of variance models. Treatment recommendations and compliance were not affected by compensation. For patients completing the spine rehabilitation program, length of treatment, flexibility, strength, lifting ability, and lower extremity work performance before and after treatment and patient satisfaction ratings were similar for the compensation and noncompensation groups. At 3 and 12 months, improvements in depression and disability were noted for both groups, but were statistically and clinically less substantial for the compensation group. At the 12 month follow-up visit, pain scores improved for the noncompensation group, but not for the compensation group.

CONCLUSIONS

In chronic low back pain, compensation involvement may have an adverse effect on self-reported pain, depression, and disability before and after rehabilitation interventions.

Impact of chronic pain patients' job perception variables on actual return to work

OBJECTIVE

To examine the impact of preinjury job perceptions on chronic pain patients (CPPs) return to work after pain facility treatment.

DESIGN

A total of 128 CPPs completed a series of rating scales and yes/no questions relating to their preinjury job perceptions and a question relating to "intent" to return to the same type of preinjury job following pain facility treatment. These CPPs were part of a grant study for prediction of return to work, and therefore their work status was determined at 1, 3, 6, 12, 18, 24, and 30 months after treatment. The preinjury job perceptions and other demographic variables were used to predict return to work. Stepwise discriminant analysis was used to predict return to work at the 1-month and final time points utilizing the above variables. Stepwise regression analysis was used to predict mean employment status (at all time points) also using the above variables.

SETTING

Multidisciplinary Pain Center.

PATIENTS

Consecutive CPPs.

RESULTS

For the 1-month time point, employment status was predicted by "intent," educational status, work dangerous perception complaint, job stress, job physical demands, job liking, and job role conflicts. Here, 79.49% of the CPPs were correctly classified. For the final time point, employment status was predicted by the first three predictors for the 1-month time point (in the same order) and age, job stress, and gender. Here, 74.58% of the CPPs were correctly classified. Mean employment status was predicted by "intent" and educational status.

CONCLUSIONS

There is a relationship between preinjury job perceptions and actual return to work after pain facility treatment. Voiced "intent" not to return to the preinjury type of job is highly predictive of not returning to work after pain facility treatment.

Outcome measures of a chronic pain program: a prospective statistical study

OBJECTIVE

To provide outcome data measuring objective and subjective variables of an individualized, multidisciplinary, comprehensive pain management program.

DESIGN

The study is a prospective evaluation of 50 consecutive patients who completed the pain management program. Objective measures were medication use and return to work. Subjective measures included self-reports of pain levels and completion of a Personal Concerns and Goals Assessment (PCGA) examining issues of lifestyle and emotional well-being. These measures were compared at program onset and completion by using appropriate statistical analyses.

RESULTS

Objective measures: Medication use by the study subjects decreased overall by 72% within all drug categories. Opioid use was eliminated. Regarding return to work, the study subjects increased their work hours by twofold overall. Of patients working fewer than 30 h per week at program onset, representing 62% of the study population, a fivefold return to work was observed. Subjective measures: Overall pain levels improved by 33%, with an 18 to 47% improvement in all descriptors (average pain levels on good or bad days, average number of good or bad days). Of the PCGA factors, patients improved 24 to 46% in all categories concerning lifestyle and emotional well-being. Correlative analysis of the data produced prognostic information as well as insights into chronic pain development.

CONCLUSIONS

This study of objective and subjective outcome measures demonstrates that a comprehensive program employing specific principles and methods produces an effective approach for the management of chronic pain. Patients disabled by chronic pain regain a quality of life that allows them to resume a functioning, productive role.