Does smoking status affect multidisciplinary pain facility treatment outcome?

OBJECTIVES: Smoking may be a major problem in chronic low back pain (LBP) patients. The goal of this study was to determine whether smoking status affected multidisciplinary pain facility treatment outcome. DESIGN: As part of a grant study, chronic LBP patients identified themselves as either current smokers (N = 81) or current nonsmokers (N = 140), and were compared by chi-square for employment status at 1, 6, 12, and 24 months after multidisciplinary pain facility treatment. Smokers who were unemployed at each time interval were then compared with employed smokers for a large number of assessment scales and clinical variables of interest by chi-square or Student's t-test. The significant independent variables from these analyses were then utilized in a logistic regression to determine predictors for smoker nonemployment. SETTING: Pain facility. RESULTS: Current smokers were less likely to be employed at each follow-up time point. Pain levels over the previous 24 hours predicted employment status for current smokers at 1-, 12-, and 24-month follow-up, while worker compensation status predicted employment status at 6 months. CONCLUSIONS: Current smoking status appears to be associated with poorer treatment outcome after multidisciplinary pain facility treatment. Return to work within smokers is predicted by pain and worker compensation status. Pain facilities should target current smokers with significant perceived pain for close treatment monitoring in an attempt to improve treatment outcome.

What percentage of chronic nonmalignant pain patients exposed to chronic opioid analgesic therapy develop abuse/addiction and/or aberrant drug-related behaviors? A structured evidence-based review.

DESIGN: This is a structured evidence-based review of all available studies on the development of abuse/addiction and aberrant drug-related behaviors (ADRBs) in chronic pain patients (CPPs) with nonmalignant pain on exposure to chronic opioid analgesic therapy (COAT). OBJECTIVES: To determine what percentage of CPPs develop abuse/addiction and/or ADRBs on COAT exposure. METHOD: Computer and manual literature searches yielded 79 references that addressed this area of study. Twelve of the studies were excluded from detailed review based on exclusion criteria important to this area. Sixty-seven studies were reviewed in detail and sorted according to whether they reported percentages of CPPs developing abuse/addiction or developing ADRBs, or percentages diagnosed with alcohol/illicit drug use as determined by urine toxicology. Study characteristics were abstracted into tabular form, and each report was characterized according to the type of study it represented based on the Agency for Health Care Policy and Research Guidelines. Each study was independently evaluated by two raters according to 12 quality criteria and a quality score calculated. Studies were not utilized in the calculations unless their quality score (utilizing both raters) was greater than 65%. Within each of the above study groupings, the total number of CPPs exposed to opioids on COAT treatment was calculated. Similarly, the total number of CPPs in each grouping demonstrating abuse/addiction, ADRBs, or alcohol/illicit drug use was also calculated. Finally, a percentage for each of these behaviors was calculated in each grouping, utilizing the total number of CPPs exposed to opioids in each grouping. RESULTS: All 67 reports had quality scores greater than 65%. For the abuse/addiction grouping there were 24 studies with 2,507 CPPs exposed for a calculated abuse/addiction rate of 3.27%. Within this grouping for those studies that had preselected CPPs for COAT exposure for no previous or current history of abuse/addiction, the percentage of abuse/addiction was calculated at 0.19%. For the ADRB grouping, there were 17 studies with 2,466 CPPs exposed and a calculated ADRB rate of 11.5%. Within this grouping for preselected CPPs (as above), the percentage of ADRBs was calculated at 0.59%. In the urine toxicology grouping, there were five studies (15,442 CPPs exposed). Here, 20.4% of the CPPs had no prescribed opioid in urine and/or a nonprescribed opioid in urine. For five studies (1,965 CPPs exposed), illicit drugs were found in 14.5%. CONCLUSION: The results of this evidence-based structured review indicate that COAT exposure will lead to abuse/addiction in a small percentage of CPPs, but a larger percentage will demonstrate ADRBs and illicit drug use. These percentages appear to be much less if CPPs are preselected for the absence of a current or past history of alcohol/illicit drug use or abuse/addiction.

Can the neuropathic pain scale discriminate between non-neuropathic and neuropathic pain?

OBJECTIVES: 1) To determine if the neuropathic pain scale (NPS) can be used to classify chronic pain patients (CPPs) as having primarily neuropathic vs non-neuropathic pain, and furthermore; 2) to determine what, if any, cut-off score can be used to reliably make this determination. DESIGN: A total of 305 CPPs consecutive admissions to The Rosomoff Pain Center were administered the NPS and were assigned a diagnosis according to the physical examination and all available test results. CPPs with a diagnosis of chronic radiculopathy and spondylolysis/degenerative arthritis were segregated into two groups for the purposes of having a group representative of neuropathic pain (chronic radiculopathy) and non-neuropathic pain (spondylolysis/degenerative arthritis). Applying neuropathic pain criteria to each "of these two groups": a neuropathic pain "subtype" was identified within the chronic radiculopathy group; and, a non-neuropathic pain "subtype" was identified within the spondylolysis/degenerative arthritis group. This step was performed in order to assure that the CPPs selected for further analysis were truly representative of neuropathic and non-neuropathic pain. Discriminant function analysis was then employed to determine if NPS scoring could differentiate between these two "subtypes." Results from the discriminant function analysis model were utilized to derive an NPS cut-off score above which CPPs would be classified as having neuropathic pain. For the diagnoses of myofascial pain syndromes, spinal stenosis, epidural fibrosis, fibromyalgia, complex regional pain syndromes 1 and 2, and failed back surgery syndrome, a predicted NPS score was calculated and compared with the cut-off score. SETTING: Multidisciplinary pain facility. PATIENTS: Chronic pain patients. RESULTS: The NPS appeared to be able to separate CPPs into neuropathic pain vs non-neuropathic pain subtypes. The derived cut-off score from the model was 5.53. Myofascial pain syndrome and spinal stenosis had predictive scores lower than this cut-off score at 3.81 and 4.26, respectively. Epidural fibrosis, fibromyalgia, complex regional pain syndromes 1 and 2, and failed back surgery syndrome had predictive scores higher than the cut-off score at 6.15, 6.35, 6.87, 9.34, and 7.19, respectively. CONCLUSIONS: The NPS appears to be able to discriminate between neuropathic and non-neuropathic pain. A debate is currently raging as to whether diagnoses, such as fibromyalgia and complex regional pain syndrome 1, can be classified as neuropathic. Our NPS cut-off score results suggest that these diagnoses may have a neuropathic pain component. The reliability and validity of our NPS method will need to be tested further in other neuropathic pain models, such as diabetic peripheral neuropathic pain.

Variables associated with current smoking status in chronic pain patients.

OBJECTIVES: Smokers may report more pain and may be at greater risk for psychiatric comorbidity. Smoking may be a major problem in chronic pain patients (CPPs). The goal of this study was to determine if pain and psychiatric comorbidity are associated with smoking status in CPPs. DESIGN: As part of a return-to-work grant study CPPs who could potentially return to work identified themselves as either current smokers (N=81) or nonsmokers (N=140). These two groups were compared on a large number of demographic, function, pain, disability, behavior, and psychiatric diagnoses variables gathered at admission into the grant study. The incidence of smoking was tested with either the student's t-test or chi-square to detect differences in continuous and categorical variables, respectively. Logistic regression was utilized to determine the predictive variables for smoking status by inputting significant independent variables (P<0.01) from the prior analyses. SETTING: Pain facility. RESULTS: Five variables were found to explain 38.8% of the variance for smoking status. These were education; race (Caucasian); cups of coffee per day; a diagnosis of current alcohol abuse/dependence; and personality disorder. CONCLUSIONS: Smoking status in CPPs is associated with some variables that are similar for smoking in the general and psychiatric populations (education, race, alcoholism). However, a number of variables expected to be relevant (e.g., mood disorders) were not associated with smoking status in CPPs. These results may not be generalizable to all CPPs as they are derived from CPPs who are return-to-work candidates.

Medicolegal rounds: medicolegal issues and alleged breaches of standards of medical care in a patient motor vehicle accident allegedly related to chronic opioid analgesic therapy.

The objective of this medicolegal case report is to present the details of the case of a chronic pain patient (CPP) who was placed on chronic opioid analgesic therapy (COAT) and was involved in a motor vehicle accident, alleged in litigation to be related to COAT. COAT standards are in a process of evolution, and this process is influenced by recent literature developments. We aim to present both the plaintiffs and defendant's expert witnesses' opinions on whether the defendant physician fell below the "standard" in allowing the CPP to drive. Both the methadone and the driving literature are utilized to explain the defendant's and plaintiffs experts' opinions and the differences between them. Based on these opinions, we have attempted to develop some recommendations on how pain physicians should approach the problem of deciding whether patients should be allowed to drive when on COAT.

Chronic pain and the measurement of personality: do states influence traits?

STUDY DESIGN: This is a structured evidence-based review of all available studies on the effect of pain, (a state phenomenon) on the measurement of personality characteristics (a trait phenomenon). OBJECTIVES: To determine whether pain treatment changes trait scores. SUMMARY OF BACKGROUND DATA: Recent evidence from the psychiatric literature indicates that the measurement of personality characteristics (traits) can be affected or changed by the presence of state psychiatric disorders, for example, depression. At issue then is whether the measurement of chronic pain patients' (CPPs') trait characteristics is affected by the presence of pain, a state problem. METHODS: Computer and manual literature searches for pain studies that reported a prepain treatment and postpain treatment (test-retest) personality test or inventory score produced 35 such reports. These references were reviewed in detail and information relating to the above problem was abstracted and placed into tabular form. Each report was also categorized as to the type of study it represented according to the guidelines developed by the Agency of Health Care Policy and Research (AHCPR). In addition, a list of 15 quality criteria was utilized to measure the quality of each study. Each study was independently categorized for each criterion as positive (criterion filled), negative (criterion not filled), or not applicable, by two of the authors. Only studies having a quality score of 65% or greater were utilized to formulate the conclusions of this review. The strength and consistency of the evidence represented by the remaining studies were then categorized according to the AHCPR guidelines. Conclusions of this review were based on these results. RESULTS: Of the 35 reports, 32 had quality scores of 65% or greater. According to the AHCPR guidelines, there was a consistent finding that the Minnesota Multiphasic Personality Inventory (MMPI) scores changed (improved) with treatment. In reference to the Millon Behavioral Health Inventory, Locus of Control, the Symptom Checklist-90-Revised (SCL-90-R), trait anxiety, and personality disorders, there were not enough studies to draw conclusions about consistency. In reference to coping/self-efficacy inventories, somatization/illness behavior inventories, and personality questionnaire studies, there was a generally consistent finding that these tests changed (improved) with pain treatment. Overall, of the 32 reports, 92.3% demonstrated a change in trait scores (improvement) with pain treatment. This evidence was categorized as consistent. Finally, 100% of a subgroup of reports (N = 12) that had controlled for pain indicated that there was a relationship between a change in pain scores and a change in trait scores. CONCLUSIONS: Based on the above results, it was concluded that some trait tests and inventories may not be pain state independent. Therefore, caution is warranted in interpreting postpain development personality profiles as being indicative of the true prepain personality structure, if measured by these tests. Why trait scores may change with treatment, confounding test-retest issues, and whether trait tests actually measure what they allegedly measure are discussed.

Lidocaine 5% patch: an open-label naturalistic chronic pain treatment trial and prediction of response.

OBJECTIVE: There have been a few open-label nonplacebo reports on the successful use of lidocaine 5% patch (L5P) for other types of pain besides postherpetic neuralgia, such as chronic low back pain. With the these reports, we began to utilize L5P routinely for chronic pain patients (CPPs) with various pain diagnoses. The purpose of this report was to describe the results of a retrospective review of this open-label naturalistic L5P chronic pain treatment trial and to attempt to delineate predictors of perceived clinical response. DESIGN: Consecutive CPPs were selected for this clinical trial according to the following inclusion criteria: the CPPs with pain greater than 6-month duration and either a hyperalgesic pain area or trigger point, which could be covered by one L5P, were offered a 3-day L5P naturalistic treatment trial. The purpose of this trial was to determine which CPPs would perceive improvement and continue using L5P. CPPs entering the trial completed the neuropathic pain scale (NPS) at entrance and completion of the trial. The senior author also completed a baseline information tool on each CPP entering this naturalistic trial. At the completion of the 3-day trial, the CPPs were asked if they perceived pain improvement with the use of L5P. In the retrospective review, the CPPs were thus segregated into two groups, those with and without perceived clinical improvement, and were statistically compared for available clinical variables. Logistic regression was then utilized to determine which significant independent variables contributed to the correct prediction of perceived improvement. SETTING: Multidisciplinary pain facility. PATIENTS: Patients with chronic pain. RESULTS: Of 362 consecutive CPPs, 114 or 31.5% were deemed candidates for this naturalistic trial. None of the CPPs refused or fulfilled exclusion criteria eliminating them from the trial. The total sample (N = 114) showed statistical improvement on all 10 NPS scales (except scales 4 and 6) plus the NPS 4, NPS nonallodynic 8, and NPS 10. The perceived clinically improved group (N = 87, 76.3% of those entering the trial), also showed perceived improvement on all preceding scales except 4 and 6. The perceived clinically nonimproved group (N = 27, 23.7% of those entering the trial) showed statistical improvement on scales B and NPS 10. Perceived improvement was predicted by the following variables: pain wakes patient up, patch placement not low back, and not in litigation. These variables explained 9.8%, 20%, and 14% of the variance, respectively. Overall, 44.5% of the variance was explained. CONCLUSIONS: A significant percentage of CPPs exposed to an L5P 3-day naturalistic trial perceived clinical improvement. However, this can only be concluded as an initial effect, and whether or not this effect is attributable to L5P cannot be derived from our data as the effect could have been nonspecific. The apparent CPP perceived clinical improvement was not associated with any particular useful clinical indicator. As such, at present, no variable can be recommended for use in selecting CPPs for such a naturalistic L5P clinical treatment trial. However, this study indicates that such a trial can be useful in selecting CPPs who may perceive benefit from L5P.

Relationships between functional capacity measures and baseline psychological measures in chronic pain patients.

The extent to which baseline psychological measures, pain, and compensation status are related to admission and posttreatment functional capacity and employment outcome was investigated. Four pass/fail functional capacity tests based on the DOT (Dictionary of Occupational Titles) classification system and previously shown to be predictive of treatment outcome in chronic pain patients were analyzed in relation to baseline measures of depression, state and trait anxiety, and perceived stress. Statistical tests of all measures with employment level at admission to treatment, 1 month follow-up and at long-term follow-up were also performed. The results showed that pain level and/or compensation status were the primary predictors of functional capacity and employment status at follow-up. Admission functional capacity measures were also predictors of employment outcome. Depression scores at admission predicted some admission functional capacity results, however, psychological scores were not as significantly related to discharge functional capacity tests. One functional capacity test, the crouching test, was an independent predictor of short- and long-term employment outcome. Trait anxiety was the only psychological factor that was independently predictive of long-term employment outcome. In conclusion, these results suggest that psychological variables are related to measures of functional capacity measured at admission. However, psychological measures at admission are not good predictors of later functional capacity measures. Functional capacity measures are important predictors of follow-up employment outcome, but return to work cannot be predicted without taking pain into account.

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.

Does the conscious exaggeration scale detect deception within patients with chronic pain alleged to have secondary gain?

OBJECTIVES: The illness behavior questionnaire (IBQ) is a test battery developed by Pilowsky to detect what he has termed abnormal illness behavior, which includes malingering. The IBQ has been widely utilized in patients with chronic pain (PWCP). Clayer developed a 21-item scale out of the IBQ, which he termed the conscious exaggeration (CE) scale. He proposed that the CE scale could detect conscious deception, i.e., malingering. The purpose of the present study is to test the CE scale in PWCP alleged to have secondary gain and thereby at greater risk for poor pain treatment outcome. It was postulated that the CE scale should generate scores in these groups significantly different from a comparison group and should predict treatment outcome in the secondary gain groups. DESIGN: A total of 96 PWCP completed the CE scale at admission and after completion of a 1-month pain facility treatment regimen. Other relevant pain variables, such as pain, depression, and anxiety, were measured and the data collected at admission and treatment completion. Work status was determined at 1, 3, 6, 12, 18, 24, and 30 months posttreatment. PWCP secondary gain subgroups (Workers' Compensation patients, patients in litigation, patients having a lawyer) were compared to the comparison group (no secondary gain factors) for treatment CE scale change scores. In order to control for the effects of pain, an analysis of covariance with pain level statistically removed was performed on admission and discharge CE scores utilizing the above patient subgroups. Pearson product correlations were utilized to determine the relationships between CE scores and psychological variables. Stepwise regression analyses were utilized to predict return to work with the CE scale score as a potential predictor. SETTING: Pain facility. PATIENTS: PWCP treated for 1 month in a pain facility. RESULTS: Overall, the analyses did not support the main hypothesis. For example, CE scale scores did not predict return to work. There was a significant degree of correlation between the variables of pain, depression, anxiety, and CE scale scores. CONCLUSIONS: PWCP characterized by the alleged secondary gain variables of Workers' compensation status, litigation, and having a lawyer did not differentially respond to the CE scale versus the comparison group. The CE scale, therefore, does not appear to be a valid instrument for identifying exaggeration in PWCP.

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

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.

Münchausen syndrome presenting with chronic pain: case report.

A factitious disorder is one that has been fabricated or simulated by the patient. Münchausen syndrome is a subtype of factitious disorder. This syndrome has not previously been described in relationship to chronic pain/chronic pain treatment units. Such a patient is presented, and the clues to the identification of this syndrome within chronic pain patients are presented.