Renee Steele Rosomoff

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

AbstractIt 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.

Does Nonsurgical Pain Center Treatment of Chronic Pain Return Patients to Work?: A Review and Meta-analysis of the Literature

Evidence in the literature relating to return to work as an outcome variable for nonsurgical treatment for chronic pain was examined. Study selection criteria were as follows: a detailed definition of patient work status, delineation of work status pre-treatment and at follow-up, and documentation of the proportion of patients employed at follow-up. Of 171 studies reviewed, 37 fulfilled these selection criteria. Because the data were objective in nature, they were abstracted by the senior author only. For the coded variables of time to follow-up, proportion of patients working pre-treatment and at follow-up and number of patients, descriptive statistics and correlations were calculated. Change in employment status at follow-up was significant (P < .005) for all groups examined. In addition, comparisons for work outcome between treated patients versus patients rejected due to lack of insurance, and between treated patients versus patients who dropped out of treatment were both significant (P < .001). The mean difference in employment at follow-up for treated patients versus those not treated was approximately 50%. The proportion of patients working increased from 20% to 54% post chronic pain nonsurgical treatment. Correlation analyses did not find a significant trend in percent employed with time to follow-up. These results indicate that (1) chronic pain nonsurgical treatment does return patients to work; (2) increased rates of return to work are due to treatment, and (3) benefits of treatment are not temporary.

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.

Are opioid-dependent/tolerant patients impaired in driving-related skills? A structured evidence-based review

Previous reviewers have concluded that opioids cause dose-related impairment in opioid-naive volunteers on psychomotor skills related to driving. Data relating to opioid-dependent/tolerant patients have not yet been reviewed. To determine what evidence, if any, exists for or against opioid-related driving skill impairment in opioid-dependent/tolerant patients, we performed a structured evidence-based review of all available studies addressing the issue of whether opioid-dependent/tolerant patients are impaired in driving-related skills. A computer and manual literature search for studies relating to opioid-dependent/tolerant patients and driving-related skills produced 48 relevant reports. These references were reviewed in detail, sorted, and placed into tabular form according to the following subject areas: (1) psychomotor abilities studies; (2) cognitive function studies; (3) effect of opioid dosing on psychomotor abilities studies; (4) motor vehicle driving violations and motor vehicle accident studies; and (5) driving impairment as measured in driving simulators and off/on road driving studies. For each topic area, each study was categorized for the type of study it represented according to guidelines developed by the Agency for Health Care Policy Research (AHCPR). The strength and consistency of the evidence in each subject area also then was categorized according to AHCPR guidelines and a quantitative method. This evidence-based review indicated the following: (1) There was moderate, generally consistent evidence for no impairment of psychomotor abilities of opioid-maintained patients; (2) There was inconclusive evidence on multiple studies for no impairment on cognitive function of opioid- maintained patients; (3) There was strong consistent evidence on multiple studies for no impairment of psychomotor abilities immediately after being given doses of opioids; (4) There was strong, consistent evidence for no greater incidence in motor vehicle violations/motor vehicle accidents versus comparable controls of opioid-maintained patients; and (5) There was consistent evidence for no impairment as measured in driving simulators off/on road driving of opioid-maintained patients. Based on the above results, it can be concluded that the majority of the reviewed studies appeared to indicate that opioids do not impair driving-related skills in opioid-dependent/tolerant patients. This evidence was consistent in four out of five research areas investigated, but inconclusive in one. As such, additional controlled studies are required. Until more data are available, however, physicians may wish to consider the approach to this problem recommended in this review.

The prediction of return to the workplace after Multidisciplinary Pain Center treatment.

The prediction of return to the workplace after Multidisciplinary Pain Center (MPC) treatment has become a major research area. To delineate the variables that predict this outcome, the authors reviewed 164 multidisciplinary outcome studies. Of these, 79 addressed work as an outcome variable. Twenty-six studies attempted to identify patient variables predicting return to the workplace. These latter studies were critically inspected for eight methodological criteria: pain location, follow-up time interval, response percentage and follow-up method, return to work subcategorization, vocational movement, univariate vs. multivariate statistics, multicolinearity and variance, and statistical treatment of dropouts. In addition, other disability studies besides those in the chronic pain area were reviewed for return to the workplace predictor variables. Of these 26 studies, only a few appeared to satisfy the criteria examined. In addition, many studies were in conflict with one another on whether a variable was predictive. The review of the nonchronic pain/disability prediction literature yielded a large number of potential predictors that related to the work area. It is unclear which variables or set of variables predict return to the workplace after MPC treatment. Chronic pain studies may be neglecting the work area as an important source of return to the workplace predictor variables.

Physical findings in patients with chronic intractable benign pain of the neck and/or back

&NA; Chronic intractable benign pain (CIBP) is defined as non‐neoplastic pain of greater than 6 months duration without objective physical findings and known nociceptive peripheral input. To test the CIBP concept, 283 consecutive chronic pain patients were examined independently by a neurosurgeon and physiatrist and only congruent physical findings were coded. Because they did not fit the CIBP definition, patients with the following primary treatment diagnoses were eliminated: degenerative disease of the spine and spinal stenosis; degenerative disease of the hips; radiculopathy; malignancy; deafferentation pain; and miscellaneous. Eliminated, also, were patients with any one finding indicative of a root compression syndrome, leaving 90 low back and 34 neck patients. These patients had abnormal physical findings in 7 categories: tender points/trigger points; decreased ranges of motion in back or neck; non‐anatomical sensory loss; rigid musculature; decreased range of hip motion; gait disturbance; and miscellaneous non‐neurologic signs. Low back CIBP patients had the following distribution among the 7 categories: 0% had findings of all 7; 1.1% had 6; 13.3% had 5; 24.4% had 4; 25.6% had 3; 26.7% had 2; 8.9% had 1; and 0% had none. Neck CIBP patients, in which only the first 4 categories of physical findings were applicable had the following distribution: 2.9% had 4; 41.2% had 3; 35.3% had 2; 20.6% had 1; and 0% had none. It was concluded that CIBP patients do have abnormal physical findings indicative of musculoskeletal disease: possibly fibrositis and/or specific myofascial syndromes, as sources of peripheral nociception. These findings question the validity of the CIBP concept and point to the need for a careful, all‐inclusive physical examination as a basic initial requirement in the classification of chronic pain patients.

Stretching in the rehabilitation of low-back pain patients

The major objective of this investigation was to study the effectiveness of the physical conditioning program used at the University of Miami Comprehensive Pain and Rehabilitation Center in restoring certain elements of the functional abilities of individuals suffering from chronic low-back pain and to evaluate the effectiveness of using a systematically applied, aggressive stretching maneuver as an add-on therapy in the treatment of chronic low-back pain patients. The effect(s) of the proposed stretching maneuver was evaluated. Twenty-eight chronic low-back pain patients were randomly assigned to one of two groups. The control group underwent a multimodal rehabilitation program, and the experimental group underwent the same rehabilitation program in addition to the systematic stretching maneuver under investigation. The results obtained showed that patients undergoing the multimodal rehabilitation program with and without the proposed systematic stretching maneuver showed a significant improvement in their functional abilities as seen from the significant increase in the static strength of the back extensors, with corresponding significant increase in back muscle myoelectric signals. Also, a significant decrease in their pain level was reported after 2 weeks of continuous treatment. The use of the systematic stretching maneuver enhanced the functional gains of chronic low-back pain patients compared to the control group.

Secondary gain concept: A review of the scientific evidence

The “secondary gain” concept originated in the psychoanalytic literature, where it was never vigorously examined. The purpose of this review is to determine if there are scientific studies that have explored the validity of this concept. DesignA computer and manual literature review yielded 166 references in which primary, secondary, and tertiary gain were mentioned. Twenty-four (14.5%) of these reports were “secondary gain” studies. Fourteen “reinforcement” studies were also found. These 38 studies were grouped according to topics and reviewed in detail. SettingAny medical treatment setting including pain treatment was utilized in the review procedure, i.e., no exclusion criteria. PatientsAny patient type, including those suffering from chronic pain, were utilized in the review procedure, i.e., no exclusion criteria. ResultsA significant but limited number of studies have investigated the “secondary gain” concept, and the results of some of these studies are in conflict. Results of some studies, however, are remarkably consistent in supporting the importance of “secondary gain” to behavior. Some studies have methodological flaws, usually relating to how the presence of secondary gain was established. ConclusionsOverall the results of the reviewed studies support the potential importance of the “secondary gain” concept to understanding illness behavior and underscore a need for future research in this area.

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.