The utility of electromyographic biofeedback in the treatment of conversion paralysis.

Conversion paralysis has a poor prognosis when there is evidence of nonresponse to previous treatment, long duration, and secondary atrophy of the "paralyzed" muscles. The authors present four such cases in which conversion paralysis was treated successfully by means of electromyographic (EMG) biofeedback. Each of the four patients also suffered from a chronic pain condition. Results from statistical analyses indicated that the four patients demonstrated significant improvement in the functional capacity of the "paralyzed" muscles as measured by isometric maximum voluntary contraction and EMG activity. The improvements occurred without explicit psychotherapy and suggest that behavioral modification techniques alone may be helpful in such cases.

Low back pain. Evaluation and management in the primary care setting.

The primary care physician plays a major role in the identification of low back pain and the entry of the patient into the health care system. Acute low back pain remits within a short period of time in most patients, and major diagnostic studies are not required. If the pain persists beyond the treatment parameters of the primary care physician, consultation is necessary. A basic component of the initial evaluation is the identification of myofascial syndromes that mimic so-called root syndromes. Further, low back pain in the population at large is not usually a surgical problem, and the chances of there being significant pathology requiring surgical or other forms of intervention may be less than 1% of those affected. When the initial attempts at treatment fail, the patient should be referred to a multidisciplinary comprehensive pain center so as to avoid or limit chronicity, the earlier, the better. Practitioners should feel comfortable in asking the centers to which they make a referral for outcome data. If these are not available, the choice should be made elsewhere. Low back pain per se is in the majority not a neurologic problem, an orthopedic problem, or a neurosurgical problem, so that consultation with these groups, unless there are strong suspicions otherwise, has limited value. The criteria for selection and referral of patients to multidisciplinary pain centers have been presented, including specific considerations for the geriatric age group. The overwhelming cost of low back pain to the economy can be decreased along with suffering and the adverse impact that pain has on all social strata.

Transverse axial tomography of the spine. Part 1: axial anatomy of the normal lumbar spine.

The authors describe the technique of transverse axial tomography of the spine and give a detailed description of the axial anatomy of the normal lumbar spine from L-4 to the sacrum. They demonstrate a specific repetitive pattern of intraosseous and articular segments, and stress the importance of the articular processes in shaping the vertebral canal and the intervertebral foramina. The authors believe axial tomography to be a simple, noninvasive radiological technique that allows cross-sectional visualization of the vertebral canal and articular processes in the living patient.

A comparison of radiographic methods of diagnosing constrictive lesions of the spinal canal. Toshiba unit vs. CT scanner.

With the advent of computerized tomography (CT), a new method of visualizing the spinal canal in cross-section has been created. Before the introduction of CT scanning, evaluation of the cross-sectional anatomy of the spinal canal was accomplished chiefly by the Toshiba unit. This study compares these two forms of tomography and discusses their relative effectiveness in diagnosing constrictive lesions of the spinal canal.

Homicide-suicide and chronic pain.

Homicide-Suicide (H-S) is a form of dual death where the murder is closely followed by the suicide of the perpetrator. H-S is extremely rare and has not previously been described within the chronic pain patient population. Such a case is presented. Psychiatric examination data from the victims of H-S revealed a number of complex, psychiatric, social, vocational, and litigation problems. Demographically the case displays some characteristics associated with suicide pacts.

Chronic pain-associated depression: antecedent or consequence of chronic pain? A review.

OBJECTIVE: To determine the current status for the association of chronic pain and depression and to review the evidence for whether depression is an antecedent or consequence of chronic pain (CP). DESIGN: A computer and manual literature review yielded 191 studies that related to the pain-depression association. These reports were reviewed and sorted into seven categories relating to the topic of this paper. Eighty-three studies were then selected according to inclusion criteria and subjected to a structured review. SETTING: Any medical treatment setting including pain treatment as inclusion criteria for selection of studies. PATIENTS: Any patients with any type of chronic pain. RESULTS: The reviewed studies were consistent in indicating that there is a statistical relationship between chronic pain and depression. For the relationship between pain and depression, there was greater support for the consequence and scar hypotheses than the antecedent hypothesis. CONCLUSIONS: Depression is more common in chronic pain patients (CPPs) than in healthy controls as a consequence of the presence of CP. At pain onset, predisposition to depression (the scar hypothesis) may increase the likelihood for the development of depression in some CPPS. Because of difficulties in measuring depression in the presence of CP, the reviewed studies should be interpreted with caution.

Drug abuse, dependence, and addiction in chronic pain patients.

It is claimed that a significant percentage of chronic pain patients suffer from drug/alcohol abuse/dependency/addiction. To address this question, 24 articles alluding to chronic pain patient drug/alcohol dependence/addiction were reviewed according to the following criteria: method for drug misuse diagnosis, which drug misuse diagnosis used (abuse, dependence, or addiction), and percentage of patients within each diagnostic category of drug misuse. The result of the review indicated that only seven studies utilized acceptable diagnostic criteria and/or definitions for the drug misuse diagnoses and gave percentages of drug misuse. Within these seven studies, the prevalence percentages for the diagnoses for drug abuse, drug dependence, and drug addiction were in the range of 3.2-18.9%. It is concluded that these diagnoses occur in a significant percentage of chronic pain patients. However, there is little evidence in these studies that addictive behaviors are common within the chronic pain population.

Completed suicide in chronic pain.

Although convergent lines of evidence indicate that one can expect a high rate of suicide completion for chronic pain patients, this problem has not previously been investigated. Follow-up data from our pain center revealed three chronic pain patients (two men and one woman) who completed suicide. These three cases are presented. The sequential nature of the data enabled us to calculate suicide rates for our chronic pain population and subsamples of this population: 16.5 women per year; 29.3 men per year; 57.1 white men and 34.9 white women in the age range of 35-64 years per year; and 78.6 white worker compensation men in the age range of 35-64 years per year. Calculation of the 95% confidence interval and comparison of these suicide rates to the general population of the United States using the Z statistic indicated that all chronic pain patient suicide rates were significantly greater than that of the general population. White men, white women, and white worker compensation men with chronic pain in the age range of 35-64 years are twice, three, and three times as likely, respectively, as their counterparts in the general population to die by suicide. Although no firm conclusions can be drawn because of the small suicide sample, these case reports indicate a need for further studies of chronic pain patient suicide rates at other pain centers.

More Munchausen with chronic pain.

Munchausen's syndrome is a popular name for a factitious disorder with physical symptoms. We have identified four Munchausen patients within a sample of 2,860 chronic pain patients for a frequency of 0.14%. These patients are described and an attempt is made to develop a profile of the Munchausen patient presenting with chronic pain.

Detoxification of nonopiate drugs in the chronic pain setting and clonidine opiate detoxification.

Although the pain physician is most familiar with the treatment of the opiate withdrawal syndrome, other drugs are abused by the chronic pain patient. The pain physician should then be familiar with the withdrawal syndromes associated with other drug groups. The withdrawal syndromes associated with hypnosedatives, psychotomimetics, nicotine, stimulants, ergot alkaloids, beta adrenergic blocking agents, antidepressants, muscle relaxants, and alpha-adrenergic agonists are described. Drug detoxification protocols for these drugs are reviewed. Additionally, the rationale for clonidine opiate detoxification is discussed, and current clonidine detoxification protocols are reviewed.

What is the quality of the implemented meta-analytic procedures in chronic pain treatment meta-analyses?

OBJECTIVE: Meta-analysis (MA) is the application of quantitative techniques for the purposes of summarizing data from individual studies. This type of review has many advantages over traditional reviews. However, different investigators performing MAs on the same data set have reached different conclusions. These reliability problems have been attributed to differences in the quality of the implemented meta-analytic procedures. We, therefore, examined the chronic pain treatment meta-analytic literature for MA procedure quality and for the consistency of conclusions. DESIGN, SETTING, PARTICIPANTS, OUTCOME MEASURES: Chronic pain treatment MAs were isolated according to inclusion/exclusion criteria. Data from these MAs were abstracted into structured tables. Table format reflected eight meta-analytic procedures identified previously as being important to MA implementation quality. These were: adequacy of retrieval, publication bias, inclusion/exclusion criteria, abstraction of data, quality, homogeneity/heterogeneity, independence, and statistical versus clinical interpretation. Each meta-analytic procedure was then independently rated by two raters. Rating results were then analyzed by procedure for each individual MA for percentage scores out of 100%, and mean scores. For MAs addressing the same topic area (pain facility treatment, antidepressant treatment, manipulation treatment) direction of effect size was noted. Mean effect sizes were calculated for these subgroups. RESULTS: Sixteen chronic pain treatment MAs fulfilled inclusion/exclusion criteria. Mean procedure ratings indicated that four procedures may not be implemented adequately. These were publication bias, abstraction of data, quality, and homogeneity/heterogeneity. There was wide MA implementation score variability, with 37.5% scoring less than 50%. The effect sizes of the MA subgroups demonstrated replicate nonvariability. CONCLUSIONS: Some meta-analytic procedures could be interpreted to be implemented inadequately in some chronic pain treatment MAs. There is wide variability between individual chronic pain treatment MAs on adequacy of implementation of these procedures. However, the effect sizes of the different MA subgroups demonstrated consistency. This finding indicates that for these MA subgroups, MA results are consistent between authors. In addition, chronic pain MAs, as compared with other groups of MAs, appear to address some of the procedures in a more adequate fashion. Future chronic pain MAs should concentrate on improving the quality of their methods with particular emphasis on the above four procedures. Because of potential validity problems with these results, these data cannot and should not be used to make administrative decisions about previous MAs.

Chronic pain disability exaggeration/malingering and submaximal effort research.

OBJECTIVE: This is the first review of chronic pain (CP) malingering/disease simulation research. The purpose of this review was to determine the prevalence of malingering within CP patients (CPPs), whether evidence exists that malingering can be detected within CPPs, and to suggest some avenues of research for this topic. DESIGN: A computer and manual literature search produced 328 references related to malingering, disease simulation, dissimulation, symptom magnification syndrome, and submaximal effort. Of these, 68 related to one of these topics and to pain. The references were reviewed in detail, sorted into 12 topic areas, and placed into tabular form. These 12 topic areas addressed the following: existence of malingering within the CP setting; dissimulation, identification simulated (faked) facial expressions of pain; identification of malingering by questionnaire; identification of malingered sensory impairment; identification of malingered loss of hand grip strength; identification of submaximal effort by isometric strength testing; identification of submaximal or malingered effort by isokinetic strength testing; identification of submaximal or malingered effort by the method of coefficient of variation; self-deception; symptom magnification syndrome; and miscellaneous malingering identification studies. Each report, in each topic area, was rated for scientific quality according to guidelines developed by the Agency for Health Care, Policy and Research (AHCPR) for rating the level of evidence presented in the reviewed study. The AHCPR guidelines were then used to rate the strength and consistency of the research evidence in each topic area based on the type of evidence the reports represented. All review conclusions were based on the results of these ratings. SETTING: Any medical setting reporting on either malingering or disease simulation, or dissimulation, or submaximal effort and pain. PATIENTS: Normal volunteers, CPPs, or any group asked to produce a submaximal or malingered effort or a malingered test profile. RESULTS: The reviewed studies indicated that malingering and dissimulation do occur within the CP setting. Malingering may be present in 1.25-10.4% of CPPs. However, because of poor study quality, these prevalence percentages are not reliable. The study evidence also indicated that malingering cannot be reliably identified by facial expression testing, questionnaire, sensory testing, or clinical examination. There was no acceptable scientific information on symptom magnification syndrome. Hand grip testing using the Jamar dynamometer and other types of isometric strength testing did not reliably discriminate between a submaximal/malingering effort and a maximal/best effort. However, isokinetic strength testing appeared to have potential for discriminating between maximal and submaximal effort and between best and malingered efforts. Repetitive testing with the coefficient of variation was not a reliable method for discriminating a real/best effort from a malingered effort. CONCLUSIONS: Current data on the prevalence of malingering within CPPs is not consistent, and no conclusions can be drawn from these data. As yet, there is no reliable method for detecting malingering within CPPs, although isokinetic testing shows promise. Claims by professionals that such a determination can be made should be viewed with caution.

The problem-oriented psychiatric examination of the chronic pain patient and its application to the litigation consultation.

OBJECTIVE: The purpose of this paper is (a) to delineate the behavior problems or complaints of chronic pain patients (CPPs) as presented in the literature and to add those behavior problems that have not yet been identified; (b) to present a semistructured psychiatric interview format that would lead to the delineation of these problems; and (c) to present a format and structure for the proposed semistructured psychiatric interview that could be utilized for the purposes of medicolegal assessment of the CPP and the reporting of that assessment to the litigation process. SETTING: Any psychiatric/psychological examination of the CPP. METHODS: The pain literature was reviewed for any research reports that specifically addressed or delineated the types of behavior problems found within the chronic pain (CP) population. These behavior problems were placed in a semistructured interview format, organized in such a way as to facilitate reporting to the litigation process if necessary. RESULTS: This semistructured psychiatric examination format is presented. Controversial problem areas in this format are discussed with appropriate references. CONCLUSIONS: CPPs are seen for the psychiatric examination with a set of behavioral problems largely determined by their medical condition, the consequences of that condition, and the social circumstances surrounding that medical condition (e.g., the litigation process). The psychiatric examination should be tailored to this special set of problems.

Is there a relationship between nonorganic physical findings (Waddell signs) and secondary gain/malingering?

This is a structured evidence based review of all available studies addressing the concept of nonorganic findings (Waddell signs) and their potential relationship to secondary gain and malingering. The objective of this review is to determine what evidence, if any, exists for a relationship between Waddell signs and secondary gain and malingering. Waddell signs are a group of 8 physical findings divided into 5 categories, the presence of which has been alleged at times to indicate the presence of secondary gain and malingering. A computer and manual literature search produced 16 studies relating to Waddell signs and secondary gain or malingering. These references were reviewed in detail, sorted, and placed into tabular form according to topic areas, which historically have been linked with the alleged possibility of secondary gain and malingering: 1) Waddell sign correlation with worker compensation and medicolegal status; 2) Waddell sign improvement with treatment; 3) Waddell sign correlation with Minnesota Multiphasic Personality Inventory validity scores; and 4) Waddell sign correlation with physician dishonesty perception. Each report in each topic area was categorized for scientific quality according to guidelines developed by the Agency for Health Care Policy and Research. The strength and consistency of this evidence in each subject area was then also categorized according to Agency for Health Care Policy and Research guidelines. Conclusions of this review were based on these results. There was inconsistent evidence that Waddell signs were not associated with worker's compensation and medicolegal status; there was consistent evidence that Waddell signs improved with treatment; there was consistent evidence that Waddell signs were not associated with invalid paper-pencil test; and there was inconsistent evidence that Waddell signs were not associated with physician perception of effort exaggeration. Overall, 75% of these reports reported no association between Waddell signs and the 4 possible methods of identifying patients with secondary gain and/or malingering. Based on the above results, it was concluded that there was little evidence for the claims of an association between Waddell signs and secondary gain and malingering. The preponderance of the evidence points to the opposite: no association.

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.

Validity of the dictionary of occupational titles residual functional capacity battery.

BACKGROUND DATA: The Dictionary of Occupational Titles (DOT) is a U.S. government publication that defines each job in the United States according to 20 job factors. Fishbain et al. (Spine 1994;19:872-80) developed a DOT residual functional capacity (RFC) battery whose predictive validity for employment/unemployment had not been tested previously. OBJECTIVES: The purposes of this study were as follows: (a) to determine whether results of a DOT-RFC battery performed at completion of pain facility treatment predicted employment status at 30 months' follow-up and (b) to determine whether the DOT-RFC battery predicted employment capacity as determined by the DOT employment levels of the chronic pain patients' (CPPs) jobs. STUDY DESIGN: This is a prospective low back pain CPP pain facility treatment study using employment status and the DOT occupational levels as outcome measures. METHODS: One hundred eighty-five consecutive CPPs who fitted the selection criteria completed a DOT-RFC battery at the completion of pain facility treatment and were contacted at 1, 3, 6, 12, 18, 24, and 30 months for determination of their employment status and DOT employment level. Eight DOT job factors plus pain and worker compensation status were found to be significantly different between employed and unemployed CPPs and between those employed in different DOT employment levels. For the 10 variables, stepwise discriminant analysis was used to select final predictor variables. Sensitivity and specificity were calculated along with pain level cutpoints that separated the groups. RESULTS: The eight DOT job factors found to be statistically significant between groups were the following: stooping, climbing, balancing, crouching, feeling shapes, handling left and right, lifting, carrying, and pain and worker compensation status. In the discriminant analysis, these variables could discriminate between the employed and unemployed categories, with a sensitivity and specificity of approximately 75%. The pain level cutpoint between employed and unemployed was 5.4 on a 10-point scale. CONCLUSIONS: We cannot as yet predict DOT-RFC employment levels. However, if a CPP can pass the above eight DOT job factors and has a pain level less than the 5.4 cutpoint, that CPP will have a 75% chance of being employed at 30 months after treatment at the pain facility. Therefore, some DOT-RFC battery job factors demonstrate a predictive validity in the "real work world."

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.

International Headache Society headache diagnostic patterns in pain facility patients.

OBJECTIVE: Previous studies have indicated that many patients with chronic pain (PWCP) referred to pain facilities for the treatment of neck and/or low back pain complain of associated headaches. The purpose of this study was to characterize the nature of these headaches according to International Headache Society (IHS) headache diagnostic criteria. DESIGN: In preparation for this study, a questionnaire that reflected IHS headache diagnostic criteria was developed. All consecutive patients admitted to our pain facility complaining of headache completed this questionnaire and received a physical and neurologic examination focused on key aspects of headache. A headache interview was also conducted, using the questionnaire as a question guide. All questionnaires were entered in a computerized database, and IHS diagnoses were arrived at for each patient. As many IHS diagnoses as possible were assigned to each PWCP as long as IHS criteria were fulfilled. In addition, a frequency distribution for headache precipitants and neck-associated symptoms was developed and evaluated by discriminant analysis to determine the diagnostic value of these factors in relation to each IHS diagnostic group. SETTING: Pain facility (multidisciplinary pain center). PATIENTS: Consecutive PWCP. RESULTS: Of 1,466 PWCP, 154 (10.5%) were identified as suffering from severe headache interfering with function. Of these, 55.8% indicated that their headaches were related to an injury for which they were seeking treatment and 83.7% had neck pain. Migraine headache represented the most common diagnostic group (90.3%), with cervicogenic headache representing the second most common (33.8%). Of the total group, 44.2% had more than one headache diagnosis, that is, there was overlap. Cervicogenic headache patients had the greatest percentage of overlap (94.2%), with migraine patients being second (68.3%). The most frequent headache precipitant was mental stress, followed by neck position and activity/exercise. The migraine and cervicogenic headache groups had a statistically significant greater number of neck-associated symptoms when compared with the remaining patients. Of the total headache group, 74.6% complained that they had a tender point at the back of their neck. Cervicogenic, migraine, and tension PWCP had the greatest frequency of head or neck tender points. The discriminant analysis for neck-associated symptoms yielded the following symptoms as the most common predictors of headache across IHS diagnostic groups: clues to onset were severe headache beginning at the neck or tender point and numbness in arms and legs; headache brought on by neck position and arms overhead; and neck symptoms consisting of a tender point in the neck and feeling severe headache in the neck. CONCLUSIONS: Headache can and should be considered a frequent comorbid condition in PWCP. Because of the overlap data, more precise diagnostic criteria may be required to separate cervicogenic headache from migraine headache. Neck-associated symptoms seem to be important even to those PWCP diagnosed with migraine headache.

I. Do chronic pain patients' perceptions about their preinjury jobs determine their intent to return to the same type of job post-pain facility treatment?

OBJECTIVE: To demonstrate that chronic pain patients' (CPPs') perceptions about their preinjury jobs determine their intent to return to the same type of job post pain facility treatment. DESIGN: A total of 225 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. The CPPs were broken down into subgroups (males, females, college males, noncollege males, college females, noncollege females), and within each subgroup those not intending to return to the same type of pre-injury job were compared to those intending to return on the preinjury job perception questions. In addition for the whole group, stepwise discriminant analysis was used to predict who planned to return to the preinjury job utilizing the job perceptions questions. SETTING: Multidisciplinary Pain Center. PATIENTS: Consecutive chronic pain patients. RESULTS: For the whole group, CPPs not intending to return were more likely to complain of job excessive physical demands, job satisfaction, and job dislike. Job perception complaints that were significantly different between the intending and not intending to return groups differed between the subgroups. For example, noncollege males not intending to return were more likely to complain of excessive physical demands only versus satisfaction and liking as significant items for college males who did not intend to return. Within the discriminant analysis, the combination of job satisfaction, excessive physical demands, employee conflicts, job liking, job dangerousness, supervisory conflicts, job stress, and age classified 73.46% of the CPPs correctly as to intent to return to the same type of preinjury job. CONCLUSIONS: There appears to be a relationship between preinjury job perceptions and intent to return to the same type of job post pain treatment. However, subgroups of CPPs will differ by which job perceptions are important towards making that decision.

II. Do chronic pain patients' perceptions about their preinjury jobs differ as a function of worker compensation and non-worker compensation status?

OBJECTIVES: (1) To demonstrate a relationship between intent to return to preinjury job and preinjury job perceptions about that job; and (2) to demonstrate that worker compensation chronic pain patients (WC CPPs) would be more likely than non-worker compensation chronic pain patients (NWC CPPs) not to intend to return to a preinjury type of job because of preinjury job perceptions. STUDY DESIGN: The relationship between preinjury job perceptions and intent to return to the preinjury job was investigated and compared between worker compensation (WC) and nonworker compensation (NWC) chronic pain patients (CPPs). Within the WC and NWC groups CPPs not intending to return to their preinjury type of work were compared to those CPPs intending to return on preinjury job perception. BACKGROUND DATA: Compensation status, being a WC CPPs or being a non-WC CPPs, has been claimed to be predictive or not predictive of return to work post pain treatment. These studies have, however, ignored the preinjury job stress perception variable as an area of research. METHODS: WC CPPs were age- and sex-matched to NWC CPPs and statistically compared on their responses to rating scale and yes/no questionnaires for intent to return to work and perceived preinjury job stress. In a second analysis, both the WC and NWC groups were divided according to their intent to return to work and statistically compared on their responses to these questionnaires. RESULTS: Both male and female WC CPPs were less likely than their counterparts to intend to return to their preinjury job. Both WC and NWC were found to complain of preinjury job complaints, and these complaints were found to differ between WC and NWC CPPs. An association between intent not to return to work and the perceptions of preinjury job dissatisfaction and job dislike was found for male and female WC CPPs and for male and female NWC CPPs. CONCLUSIONS: There may be a relationship between some preinjury job perceptions and intent to return to the preinjury type of work in some groups of CPPs. However, a specific relationship between WC status, intent not to return to the preinjury type of work, and preinjury job perceptions in comparison to NWC CPPs could not be demonstrated.