Does pain relief improve pain behavior and mood in chronic pain patients?

Profile of Mood States Factor Structure Does Not Accurately Account for Patients with Chronic Pain

OBJECTIVE

The need for measuring emotional functioning in patients with chronic pain was recognized decades ago. The Initiative on Methods, Measures, and Pain Assessment in Clinical Trials (IMMPACT) proposed the Profile of Mood States for this purpose. However, to date, its factor structure has not been confirmed in these patients.

METHODS

We set out to use confirmatory factor analysis to test the theoretical structure of seven factors: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Vigor-Activity, Fatigue-Inertia, Confusion-Bewilderment, and Friendliness.

PARTICIPANTS

The sample consisted of 588 Spanish adult patients with chronic pain.

RESULTS

The original structure could not be verified according to the obtained fit indices (e.g., root-mean-square error of approximation = 0.11). For this reason, we carried out a second study that relied on exploratory factor analysis to evaluate the structure in half of the cases and confirmatory factor analysis to validate it in the other half. The factor structure detected in the exploratory factor analysis was not satisfactory, nor could it be validated with confirmatory factor analysis (e.g., normed fit index between 0.54 and 0.56).

CONCLUSIONS

The factor structure of the Profile of Mood States could not be satisfactorily confirmed. Consequently, other mood measures and shorter, optimized versions of the POMS are discussed as possible alternatives.

Effect of Intensive Acupuncture on Pain-Related Social and Psychological Variables for Women with Chronic Neck and Shoulder Pain – An Rct with Six Month and Three Year Follow Up

Objectives

This study examines whether intensive acupuncture treatment can improve several social and psychological variables for women with chronic pain in the neck and shoulders, and whether possible effects are long-lasting. The effects on pain have been reported elsewhere.

Methods

Twenty-four female office workers (47±9 years old, mean ± SD) who had had neck and shoulder pain for 12±9 years, were randomly assigned to a test group or a control group. Acupuncture was applied 10 times during three to four weeks either at presumed acupuncture points for pain (test group) or at sham points (control group). In addition, acupressure was given to patients between treatments, at either real or sham points. Questionnaires for social and psychological variables were completed before each treatment, just after the course, and six months and three years later.

Results

The pain-related activity impairment at work was significantly less in the test group than the controls by the end of treatment (P<0.04). Also there were significant differences between the groups for quality of sleep, anxiety, depression and satisfaction with life (P<0.05). At six months and three years follow ups the acupuncture group showed further improvements in most variables and was again significantly different from the control group.

Conclusion

Intensive acupuncture treatment may improve activity at work and several relevant social and psychological variables for women with chronic pain in the neck and shoulders. The effect may last for at least three years.

Osteoarthritis patients with pain improvement are highly likely to also have improved quality of life and functioning. A post hoc analysis of a clinical trial

BACKGROUND

This analysis evaluated whether osteoarthritis patients achieving the greatest pain control and lowest pain states also have the greatest improvement in functioning and quality of life.

METHODS

Patients (n=419) who failed prior therapies and who were switched to etoricoxib 60mg were categorized as pain responders or non-responders at 4 weeks based on responder definitions established by the Initiative on Methods, Measurement, and Pain (IMMPACT) criteria, including changes from baseline of ≥15%, ≥30%, ≥50%, ≥70% and a final pain status of ≤3/10 (no worse than mild pain). Pain was assessed at baseline and 4 weeks using 4 questions from the Brief Pain Inventory (BPI) (worst pain, least pain, average pain, and pain right now), and also using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscale. We examined the relationship between pain responses with changes from baseline in two functional measures (the BPI Pain Interference questions and the WOMAC Function Subscale) as well as changes from baseline in quality of life (assessed on the SF-36 Physical and Mental Component Summaries). We also sought to understand whether these relationships were influenced by the choice of the pain instrument used to assess response. We contrast the mean difference in improvements in the functional and quality of life instruments based on pain responder status (responder versus non-responder) and the associated 95% confidence limits around this difference.

RESULTS

Patients with better pain responses were much more likely to have improved functional responses and improved quality of life, with higher mean changes in these outcomes versus pain non-responders, regardless of the choice of IMMPACT pain response definition (e.g., using any of 15%, 30%, 50%, 70% change from baseline) or the final pain state of ≤3/10. There was an evident gradient, where higher levels of pain response were associated with greater mean improvements in function and quality of life. The finding that greater pain responses led to greater functional improvements and quality of life gains was not dependent on the manner in which pain was evaluated. Five different pain instruments (e.g., the 4 questions on pain from the BPI pain questionnaire and the WOMAC pain subscale) consistently demonstrated that pain responders had statistically significantly greater improvements in function and quality of life compared to pain non-responders. This suggests these results are likely to be generalizable to any validated pain measure for osteoarthritis.

CONCLUSIONS

Pain is an efficient outcome measure for predicting broader patient response in osteoarthritis. Patients who do not achieve timely, acceptable pain states over 4 weeks were less likely to experience functional or quality of life improvements.

IMPLICATIONS

Good pain improvements in osteoarthritis with a valid pain instrument are a proxy for good improvements in both function and quality of life. Therefore proper osteoarthritis pain assessment can lead to efficient evaluations in the clinic.

Does pain interfere with antidepressant depression treatment response and remission in patients with depression and pain? An evidence-based structured review

OBJECTIVE

The objective of this evidence-based structured review was to determine if there is consistent evidence that pain interferes with achieving antidepressant treatment response/remission of depression in patients with depression and pain.

METHODS

After exclusion criteria were applied, of 2,801 studies/reports, 17 studies addressed this question. They were sorted into the four hypotheses outlined herein after. The percentage of studies supporting/not supporting each hypothesis was calculated. The strength and consistency of the evidence for each hypothesis were rated according to the Agency for Health Care Research and Quality (AHRQ) guidelines.

RESULTS

For the first hypothesis (pretreatment pain levels will predict antidepressant depression response), nine out of 10 (90%) studies supported it. For the second hypothesis (treatment decreases in pain will be associated with antidepressant depression response), two out of two (100%) studies supported it. For the third hypothesis (pretreatment pain levels will predict antidepressant depression remission), six out of six (100%) studies supported it. For the fourth hypothesis (treatment decreases in pain will be associated with antidepressant depression remission), five out of five (100%) supported it. Utilizing these percentages and AHRQ guidelines, hypotheses 1, 3, and 4 received an A rating for consistency of studies in supporting them. A consistency rating for hypothesis 2 could not be generated because of too few studies in that group.

CONCLUSIONS

Consistent evidence was found that antidepressant treatment of depression in patients with depression and pain can be negatively impacted by pain for achieving depression response/remission. However, the overall number of studies supporting each hypothesis was small. In addition, several potential confounders of the results of this study were identified.

Therapeutic effects of 15 Hz pulsed electromagnetic field on diabetic peripheral neuropathy in streptozotocin-treated rats

Although numerous clinical studies have reported that pulsed electromagnetic fields (PEMF) have a neuroprotective role in patients with diabetic peripheral neuropathy (DPN), the application of PEMF for clinic is still controversial. The present study was designed to investigate whether PEMF has therapeutic potential in relieving peripheral neuropathic symptoms in streptozotocin (STZ)-induced diabetic rats. Adult male Sprague-Dawley rats were randomly divided into three weight-matched groups (eight in each group): the non-diabetic control group (Control), diabetes mellitus with 15 Hz PEMF exposure group (DM+PEMF) which were subjected to daily 8-h PEMF exposure for 7 weeks and diabetes mellitus with sham PEMF exposure group (DM). Signs and symptoms of DPN in STZ-treated rats were investigated by using behavioral assays. Meanwhile, ultrastructural examination and immunohistochemical study for vascular endothelial growth factor (VEGF) of sciatic nerve were also performed. During a 7-week experimental observation, we found that PEMF stimulation did not alter hyperglycemia and weight loss in STZ-treated rats with DPN. However, PEMF stimulation attenuated the development of the abnormalities observed in STZ-treated rats with DPN, which were demonstrated by increased hind paw withdrawal threshold to mechanical and thermal stimuli, slighter demyelination and axon enlargement and less VEGF immunostaining of sciatic nerve compared to those of the DM group. The current study demonstrates that treatment with PEMF might prevent the development of abnormalities observed in animal models for DPN. It is suggested that PEMF might have direct corrective effects on injured nerves and would be a potentially promising non-invasive therapeutic tool for the treatment of DPN.

Antinociceptive effects of combination of tramadol and acetaminophen on painful diabetic neuropathy in streptozotocin-induced diabetic rats

OBJECTIVE

The purpose of this study was to establish the streptozotocin (STZ)-induced diabetic model with rats and investigate the antinociceptive effect of combination of Tramadol (TR) and Acetaminophen (NAPA) on the animal model for the first time.

METHODS

Diabetic model was induced by a single injection of STZ (60 mg/kg, intraperitoneal). Nociceptive thresholds were measured by means of electronic von Frey test, hot-plate test, and tail-flick test. On the 28th day of diabetes induction, diabetic rats with significant hyperalgesia were randomly divided into three groups: TR, NAPA, and TR-NAPA combination group. Each group was randomly divided into four subgroups. Three geometric series of drugs were given to each group respectively. Antinociceptive effects of the drugs were assessed at 15, 30, 60, 120, and 180 minutes after drug administration. 50% Maximum antinociceptive effect of each drug was determined by probit analysis, whereas interaction between TR and NAPA was evaluated by isobolographic analysis.

RESULTS

Hyperalgesia, along with hyperglycemia, developed 4 days after STZ injection and persisted at all tested time points until 28 days. TR, NAPA, and TR-NAPA combination administration all produced dose-dependent antinociceptive effects. Isobolographic analysis showed a significant deviation of TR/NAPA 50% maximum antinociceptive effect (in tail-flick test, but not in von Frey test) from the additive line.

CONCLUSIONS

Combination of the two drugs produces an additive antinociceptive effect in tail-flick test, whereas probable additive antinociceptive effect in von Frey test in painful diabetic neuropathy rats.

Fibromyalgia: Moderate and substantial pain intensity reduction predicts improvement in other outcomes and substantial quality of life gain

Chronic pain is associated with a range of other problems, including disturbed sleep, depression, anxiety, fatigue, reduced quality of life, and an inability to work or socialise. We investigated whether good symptom control of pain (using definitions of moderate and substantial benefit) is associated with improvement in other symptoms. Individual patient data from four randomised trials in fibromyalgia (2575 patients) lasting 8-14weeks were used to calculate percentage pain reduction for each completing patient (1858), divided into one of five groups according to pain reduction, irrespective of treatment: substantial benefit - 50% pain reduction; moderate - 30% to <50%; minimal - 15% to <30%; marginal - 0% to <15%; worse - <0% (increased pain intensity). We then calculated change from baseline to end of trial for measures of fatigue, function, sleep, depression, anxiety, ability to work, general health status, and quality-adjusted life year (QALY) gain over a 12-month period. Substantial and moderate pain intensity reductions were associated with statistically significant reduction from baseline by end of trial in all measures, with values by trial end at or approaching normative values. Substantial pain intensity reduction resulted in 0.11 QALYs gained, and moderate pain intensity reduction in 0.07 QALYs gained over a 12-month period. Substantial and moderate pain intensity reduction predicts broad beneficial outcomes and improved quality of life that do not occur without pain relief. Pain intensity reduction is a simple and effective predictor of which patients should continue treatment, and which should discontinue and try an alternative therapy.

Interpreting the clinical importance of treatment outcomes in chronic pain clinical trials: IMMPACT recommendations

A consensus meeting was convened by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to provide recommendations for interpreting clinical importance of treatment outcomes in clinical trials of the efficacy and effectiveness of chronic pain treatments. A group of 40 participants from universities, governmental agencies, a patient self-help organization, and the pharmaceutical industry considered methodologic issues and research results relevant to determining the clinical importance of changes in the specific outcome measures previously recommended by IMMPACT for 4 core chronic pain outcome domains: (1) Pain intensity, assessed by a 0 to 10 numerical rating scale; (2) physical functioning, assessed by the Multidimensional Pain Inventory and Brief Pain Inventory interference scales; (3) emotional functioning, assessed by the Beck Depression Inventory and Profile of Mood States; and (4) participant ratings of overall improvement, assessed by the Patient Global Impression of Change scale. It is recommended that 2 or more different methods be used to evaluate the clinical importance of improvement or worsening for chronic pain clinical trial outcome measures. Provisional benchmarks for identifying clinically important changes in specific outcome measures that can be used for outcome studies of treatments for chronic pain are proposed.

PERSPECTIVE

Systematically collecting and reporting the recommended information needed to evaluate the clinical importance of treatment outcomes of chronic pain clinical trials will allow additional validation of proposed benchmarks and provide more meaningful comparisons of chronic pain treatments.

Does a Combination of Intensive Cognitive-Behavioral Pain Management and a Spinal Implantable Device Confer any Advantage? A Preliminary Examination

Research suggests that a combination of a somatic and a psychosocial intervention for chronic noncancer pain should be associated with a better outcome than either alone. This study presents data on a series of 31 patients who underwent sequential treatment with an implantable device targeting pain relief and a cognitive-behavioral pain management program that targeted improved function. A combination of treatments was used as there was a suboptimal response to the initial treatment. There were improvements in a range of outcomes at a long-term follow-up. Significant improvements were found in disability, affective distress, self-efficacy, and catastrophizing, but not in average pain severity. Further analyses failed to demonstrate an order effect. These results support the view that combined somatic and psychosocial interventions can achieve better outcomes than either alone in selected chronic pain patients. This approach requires that psychological assessment is essential before the use of an implantable device. This may not only improve patient selection, but also identify psychosocial factors that may be modified to enhance the effectiveness of invasive interventions. In addition, consideration for an implantable device following a suboptimal response to treatment in a cognitive-behavioral pain management program should include a re-evaluation of the patients' beliefs and use of self-management (coping) strategies before deciding on further treatment options.

The Impact of Therapy on Quality of Life and Mood in Neuropathic Pain: What Is the Effect of Pain Reduction?

Mood and quality of life (QOL) outcomes vary widely in neuropathic pain trials. This may be a result of variable analgesia and other treatment effects. We evaluated the relationship between pain reduction and mood/QOL in neuropathic pain. Pain, side effects, QOL, and mood from a trial of morphine, gabapentin, and a morphine-gabapentin combination were examined. Baseline QOL was impaired according to Short Form Health Survey (SF-36) scores. Baseline mood, according to Profile of Mood States scores, was comparable to that of a nondepressed population. Pain reduction with all three active trial treatments correlated with improved QOL. Pain reduction with morphine and with gabapentin correlated with improved mood. Pain reduction with a morphine-gabapentin combination correlated with improvement in only one of several domains of the Profile of Mood States. Severity of sedation, constipation, and dry mouth during any treatment did not correlate with mood/QOL changes. These results can be interpreted to imply that larger analgesic treatment effect sizes lead to more substantial improvements in QOL and/or mood. However, other beneficial or adverse treatment-related side effects may also affect mood/QOL. Therefore, future studies are needed to also evaluate the impact of treatment-related side effects on mood/QOL in analgesic trials.

Using opioids with persisting noncancer pain: a biopsychosocial perspective

OBJECTIVE

Despite the growing use of opioids for persisting noncancer pain, evidence for their effectiveness is limited, especially in relation to functional outcomes. Guidelines have been developed for prescribers, but their utility is untested. This review examines the use of opioids in this population from a biopsychosocial perspective and makes a number of recommendations.

DATA SOURCES

Published comparison studies and reviews of oral opioids in chronic noncancer pain, as well as 5 published guidelines for the prescription of opioids and systematic reviews of cognitive-behavioral pain management programs.

METHODS

Outcomes of the opioid comparison studies were reviewed and compared to those achieved by pain management programs.

CONCLUSIONS

The available evidence indicates that by themselves, oral opioids generally achieve only modest reductions in pain levels in patients with chronic noncancer pain. Functional outcomes are inconsistent across studies. There are questions about the timing of their use and patient selection. There are risks in trials of opioids only after other conservative interventions have been tried unsuccessfully. Also, in some patients, ongoing use of opioids risks repeated over-doing of pain-generating activities and reinforcing escape/avoidance responses that promote disability. These risks may be lessened by assessment of current use of pain self-management strategies among potential candidates for opioids. This offers advantages in promoting collaborative management of persisting pain as well as better pain and functional outcomes. In this view, opioids may be considered as one possible element of a management plan rather than the primary treatment.

Sustained sleep restriction reduces emotional and physical well-being

BACKGROUND

Chronic insufficient sleep is a common finding in many pain-related and other medical diseases and is frequently experienced in the general population. Prolonged curtailment of nocturnal sleep has been studied for its adverse effect on cognitive functioning and subjective tiredness, but relatively little is known about its effect on mood and physical symptoms.

OBJECTIVE

In order to test whether sleep restriction to 50% of the habitual time over 12 days affects diurnal and day-to-day variation of subjective ratings of mood and physical symptoms, 108 adjectives and statements were self-rated using visual analog scales every 2h during the waking period.

DESIGN

Randomized, 16-day controlled in-laboratory study.

SETTING

General Clinical Research Center (GCRC).

PARTICIPANTS

Forty healthy subjects aged 21-40 years (14 females, 26 males).

INTERVENTION

Subjects were randomized to either 4h of sleep per night (11 pm-3 am, N=22) or 8h of sleep per night (11 pm-7 am, N=18) for 12 consecutive days.

MAIN OUTCOME MEASURE

Changes in the factor-derived variables optimism-sociability, tiredness-fatigue, anger-aggression, bodily discomfort, and items constituting bodily discomfort were compared between groups.

RESULTS

Optimism-sociability progressively declined over consecutive days of sleep restriction by 15%. Bodily discomfort showed a slight, but significant interindividual increase of 3% across days of sleep restriction due to significant increases of generalized body pain, back pain, and stomach pain. Optimism-sociability and tiredness-fatigue showed diurnal variations with a quadratic function period within each day in both conditions.

CONCLUSION

The data suggest that chronic insufficient sleep may contribute to the onset and amplification of pain and affect health by compromising optimistic outlook and psychosocial functioning.

Pain severity in diabetic peripheral neuropathy is associated with patient functioning, symptom levels of anxiety and depression, and sleep

Our goal was to evaluate pain severity, pain-related interference with function, sleep impairment, symptom levels of anxiety and depression, and quality of life among patients with painful diabetic peripheral neuropathy (DPN). Participants in a burden of illness survey (n = 255) completed the modified Brief Pain Inventory-DPN (BPI-DPN), MOS Sleep Scale, Hospital Anxiety and Depression Scale (HADS), Short Form Health Survey-12v2 (SF-12v2), and the EuroQoL (EQ-5D). Patients were 61 +/- 12.8 years old (51.4% female), had diabetes for 12 +/- 10.3 years and painful DPN for 6.4 +/- 6.4 years. Average and Worst Pain scores (BPI-DPN, 0-10 scales) were 5.0 +/- 2.5 and 5.6 +/- 2.8. Pain substantially interfered (>or=4 on 0-10 scales) with walking ability, normal work, sleep, enjoyment of life, mood, and general activity. Moderate to severe symptom levels of anxiety and depression (HADS-A and HADS-D scores >or=11 on 0-21 scales) occurred in 35% and 28% of patients, respectively. Patients reported greater sleep problems compared with the general U.S. population and significant impairment in both physical and mental functioning (SF-12v2) compared with subjects with diabetes. The mean EQ-5D utility score was 0.5 +/- 0.3. Greater pain levels in DPN (mild to moderate to severe) corresponded with higher symptom levels of anxiety and depression, more sleep problems, and lower utility ratings and physical and mental functioning, (all Ps < 0.01). Painful DPN is associated with decrements in many aspects of patients' lives: physical and emotional functioning, affective symptoms, and sleep problems. The negative impact is higher in patients with greater pain severity.