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This study examined the effects of interstimulus interval (ISI) on heat-evoked temporal summation of second pain (TSSP) and tested whether greatest maintenance of TSSP would occur at longer ISIs in older adults. Several lines of evidence support that TSSP is associated with central sensitization and is centrally mediated. The participants were 198 community-dwelling adults divided into 3 age cohorts (18-39, 40-59, and 60-78 years of age). Six TSSP trials used a train of 10 contacts with a preheated probe that made repetitive contact with the volar forearm. Participants completed 2 trials at each ISI of 2.5, 3.5, and 4.5 seconds. The intraclass correlations for each pair of trials support the reliability of the current methodology. Temporal summation of second pain scores declined in a time-dependent manner across ISI. In addition, greater maintenance of TSSP at longer ISIs was observed in middle-aged and older age groups compared with the younger cohort. Significant associations were found between TSSP and measures of recent pain. Greater summation at longer ISIs in older adults would suggest slower decay of excitability in spinal neurons and infer increased risk for central sensitization with advancing age.

Protocols of temporal summation (TS) of pain typically involve the delivery of brief repetitive noxious pulses of a constant intensity while measuring the perceived intensity of pain after each pulse. The size percept of noxious repetitive stimulation has been poorly characterized. Furthermore, no studies have investigated age differences in TS of cold pain. The current study examined TS of pain intensity and the perceived size of the painful area during repetitive noxious heat and cold pulses in healthy younger (n = 104) and older adults (n = 40). Trials of 10 brief repetitive noxious heat or cold pulses were delivered to the upper extremities. Participants rated the perceived size of the painful area or intensity of pain after each pulse. The magnitude of change for the size percept and intensity for pain were calculated for each trial. The results indicated that older adults experienced greater TS of the size percept of cold stimuli compared with younger adults. Additionally, older women experienced greater TS of the size percept of heat stimuli compared with older men and all younger participants. No overall age or sex differences were found in the TS of pain intensity for cold or heat trials. These results suggest dysfunctional modulation of the spatial percept of the painful stimuli by older adults, and in particular older women, during repetitive noxious thermal pulses.

The prevalence estimates of chronic pain among adults in the United States may be as high as 40%, affecting approximately 100 million adults (15). Pain increases physical disability (32), reduces quality of life, and is costly to both the individual experiencing pain and the nation (15). Alarmingly, a recent study reported that the national cost of pain exceeds the cost of the nation’s priority health conditions (e.g., cardiovascular disease, neoplasms, endocrine, nutritional and metabolic diseases), with costs ranging from $560 to $635 billion annually (15). Clearly, a need exists for effective methods to prevent and treat chronic pain. A rapidly growing body of evidence suggests that exercise may be a viable means to aid in the prevention of chronic pain and reduce ongoing pain symptoms in chronic pain populations. Indeed, data from observational studies (23), randomized controlled trials (19), and laboratory studies suggest a relationship between levels of physical activity and chronic pain (12, 26). For example, RCTs demonstrate that systematic aerobic exercise reduces pain symptoms and improves physical function in multiple chronic widespread (19) and regional pain conditions (17). Additionally, recent laboratory studies have showed that subjective and objective measures of physical activity are negatively related to suprathreshold pain sensitivity of painful heat stimuli in FMS patients (13, 26). A few studies have examined the relationship between pain sensitivity and physical activity in healthy adults. Most recently, Ellingson and colleagues found that greater vigorous physical activity as measured by accelerometers was significantly related to reduced pain intensity and unpleasantness ratings to noxious thermal stimuli in healthy, younger women (12). Similarly, Adrzejewski et al. revealed that pressure pain thresholds at a variety of skeletal muscles sites were higher in younger adults who reported engaging in vigorous physical activity compared to those who reported participation in only moderate physical activity (3). Anshel and Russel demonstrated that an aerobic training intervention increased pressure pain tolerance compared to a control group with no exercise training (4). While these studies suggest a link between physical activity and pain sensitivity, it is not known whether levels of physical activity are related to the functionality of pain modulatory processes. Importantly, several studies have shown that regular physical exercise exerts beneficial effects on several biological mediators (e.g., serotonin, endogenous opioids) of pain inhibition and facilitation (1,14,34). Pain is modulated by complex endogenous systems that both facilitate and inhibit pain. Alterations in the function of these systems have been implicated in multiple chronic pain conditions (24) and in older adults (31). Several sophisticated tests of pain modulatory mechanisms exist in the pain literature. Dysfunction of pain facilitation has often been assessed by the method of temporal summation. This procedure consists of the administration of short-duration repeated noxious stimuli of a constant intensity and measuring the consequent increase in pain as an indirect method of evaluating sensitization of the central nervous system (11). Endogenous pain inhibition has typically been assessed by a “pain inhibits pain” model termed conditioned pain modulation (CPM) or a model called offset analgesia (offset). CPM is the central inhibition of pain in a local area by a second pain that can be experienced anywhere in the body (38). Offset is an inhibitory temporal sharpening mechanism characterized by a pronounced reduction in perceived pain intensity evoked by slight decreases in noxious temperatures compared to those of equal magnitude increases (16). To date, no studies have investigated whether individuals who are more physically active exhibit enhanced descending pain modulatory function using the tests of temporal summation of pain, CPM, or offset analgesia. The purpose of this study was threefold. We sought to determine whether self-reported levels of physical activity in healthy adults predicted 1) pain sensitivity to heat and cold stimuli, 2) pain facilitory function as tested by temporal summation of pain, and 3) pain inhibitory function as tested by CPM and offset analgesia. We hypothesized that participants who reported relatively greater levels of physical activity would exhibit less pain sensitivity to thermal stimuli, reduced temporal summation of pain, and greater inhibition of pain via CPM and offset analgesia.

OBJECTIVES To describe and understand varieties and characteristics of sensitization contributing to hyperalgesia in participants with chronic pain conditions. METHODS Thermal stimulation was delivered to the face, forearm, and calf of pain-free participants and individuals with irritable bowel syndrome, temporomandibular pain disorder (TMD), and fibromyalgia syndrome (FM). Three-second contacts by a preheated thermode occurred at 30-second intervals in ascending and then in descending series (0.7°C steps). RESULTS Thermal pain ratings during ascending series were greater at each site in individuals diagnosed with chronic pain. Intense pain at the time of testing further enhanced the ratings at all sites, but mild or moderate clinical pain did not have this effect. Thermal pain in all participants was greater during descending series compared with the ascending series of arm and leg stimulation. The hypersensitivity during the descending series was comparable in pain-free, FM and TMD participants but was increased in duration for arm or leg stimulation of FM participants. DISCUSSION The widespread sensitization for irritable bowel syndrome and TMD participants does not rely on mechanisms of spatial and temporal summation often invoked to explain widespread hyperalgesia associated with chronic pain. Increased sensitivity during descending series of stimulation of an arm or leg but not the face indicates a propensity for sensitization of nociceptive input to the spinal cord. Abnormally prolonged sensitization for FM participants reveals a unique influence of widespread chronic pain referred to deep somatic tissues.

Movement-evoked pain: transforming the way we understand and measure pain Duane Corbett;Corey Simon;Todd Manini;Steven George;Joseph Riley;Roger Fillingim; PAIN

Robust inter-individual variation in pain sensitivity has been observed and recent evidence suggests that some of the variability may be genetically-mediated. Our previous data revealed significantly higher pressure pain thresholds among individuals possessing the minor G allele of the A118G SNP of the mu-opioid receptor gene (OPRM1) compared to those with two consensus alleles. Moreover, ethnic differences in pain sensitivity have been widely reported. Yet, little is known about the potential interactive associations of ethnicity and genotype with pain perception. This study aimed to identify ethnic differences in OPRM1 allelic associations with experimental pain responses. Two-hundred and forty-seven healthy young adults from three ethnic groups (81 African Americans; 79 non-white Hispanics; and 87 non-Hispanic whites) underwent multiple experimental pain modalities (thermal, pressure, ischemic, cold pressor). Few African Americans (7.4%) expressed the rare allele of OPRM1 compared to non-Hispanic-whites and Hispanics (28.7% vs. 27.8%, respectively). Across the entire sample, OPRM1 genotype did not significantly affect pain sensitivity. However, analysis in each ethnic group separately revealed significant genotype effects for most pain modalities among non-Hispanic-whites (ps

Affect is neurobiologically based, influences emotions, contributes to temperamental characteristics, and can be evaluated from both state and trait perspectives. Associations between state-related positive affect (PA), negative affect (NA), and chronic pain have been investigated. However, little is known about the relationship between trait affect patterns and pain-related experiences. Affect balance style (ABS) provides a framework to assess the combined contribution of trait PA and NA. Psychological factors and experimental pain sensitivity are indicated as predictors of chronic pain onset. The current study investigated the relationship between ABS, pain sensitivity, and pain-related measures in healthy adults.Participants (n=372) completed quantitative sensory testing, pain-related questionnaires, and the Positive and Negative Affect Scale. ABS groups were categorized as Healthy (high PA, low NA), Low (low PA, low NA), Depressive (low PA, high NA), and Reactive (high PA, high NA). Z-scores were computed for 3 experimental pain measures: ischemic, pressure, and heat.ABS groups significantly differed on ischemic pain sensitivity and pain-related measures. Specifically, the Healthy group demonstrated lower ischemic pain sensitivity compared with the Reactive group (P=0.02); the Depressive and Reactive groups endorsed higher somatic symptoms compared with the Healthy group (P0.02); the Low and Depressive groups reported more physical stimuli sensitivity than the Healthy group (P0.02); and the Reactive group indicated more passive coping strategies then the Low and Healthy groups (P=0.001).Findings from the study suggest that among healthy adults, trait affect patterns are associated with ischemic experimental pain sensitivity and other pain-related measures.

Studies have demonstrated menstrual cycle influences on basal pain perception, but direct evidence of menstrual cycle influences on analgesic responses has not been reported in humans. Our aim was to determine whether the magnitude of morphine and pentazocine analgesia varied across the menstrual cycle. Sixty-five healthy women, 35 taking oral contraceptives (OC) and 30 normally cycling (NOC), underwent experimental pain assessment both before and after intravenous administration morphine (0.08mg/kg) or pentazocine (0.5mg/kg) compared to saline placebo. Both active drug and placebo were administered once during the follicular phase and once during the luteal phase. Measures of heat, ischemic, and pressure pain sensitivity were obtained before and after drug administration. Change scores in pain responses were computed to determine morphine and pentazocine analgesic responses, and medication side effects were recorded. The data were analyzed using mixed-model analyses of variance. NOC women showed slightly greater heat pain sensitivity in the follicular vs luteal phase, while the reverse pattern emerged for OC women (P=0.046). Also, OC women showed lower pressure pain thresholds compared to NOC women (P

Previous investigations of somatic hypersensitivity in IBS patients have typically involved only a single stimulus modality, and little information exists regarding whether patterns of somatic pain perception vary across stimulus modalities within a group of patients with IBS. Therefore, the current study was designed to characterize differences in perceptual responses to a battery of noxious somatic stimuli in IBS patients compared to controls. A total of 78 diarrhea-predominant and 57 controls participated in the study. We evaluated pain threshold and tolerance and sensory and affective ratings of contact thermal, mechanical pressure, ischemic stimuli, and cold pressor stimuli. In addition to assessing perceptual responses, we also evaluated differences in neuroendocrine and cardiovascular responses to these experimental somatic pain stimuli. A subset of IBS patients demonstrated the presence of somatic hypersensitivity to thermal, ischemic, and cold pressor nociceptive stimuli. The somatic hypersensitivity in IBS patients was somatotopically organized in that the lower extremities that share viscerosomatic convergence with the colon demonstrate the greatest hypersensitivity. There were also changes in ACTH, cortisol, and systolic blood pressure in response to the ischemic pain testing in IBS patients when compared to controls. The results of this study suggest that a more widespread alteration in central pain processing in a subset of IBS patients may be present as they display hypersensitivity to heat, ischemic, and cold pressor stimuli.

Females with Irritable Bowel Syndrome (IBS) and Temporomandibular Disorder (TMD) are characterized by enhanced sensitivity to experimental pain. One possible explanation for this observation is deficiencies in pain modulation systems such as Diffuse Noxious Inhibitory Control (DNIC). In a few studies that used brief stimuli, chronic pain patients demonstrate reduced DNIC. The purpose of this study was to compare sensitivity to prolonged heat pain and the efficacy of DNIC in controls to IBS and TMD patients. Heat pain (experimental stimulus; 44.0-49.0 degrees C), which was applied to left palm, was continuously rated during three 30-s trials across three separate testing sessions under the following conditions: without a conditioning stimulus; during concurrent immersion of the right foot in a 23.0 degrees C (control); and during noxious cold immersion in a (DNIC; 8.0-16.0 degrees C) water bath. Compared to controls, IBS and TMD patients reported an increased sensitivity to heat pain and failed to demonstrate pain inhibition due to DNIC. Controls showed a significant reduction in pain during the DNIC session. These findings support the idea that chronic pain patients are not only more pain sensitive but also demonstrate reduced pain inhibition by pain, possibly because of dysfunction of endogenous pain inhibition systems.

Objective: Over a decade ago, Jamison noted the lack of studies that identify patient profiles or specific groups that might be best suited for opioid treatment of chronic noncancer pain. Methods: This paper reviews the studies that provide evidence for individual differences in opioid analgesia for chronic noncancer pain. Results: What we have found is that few investigations have addressed these important aspects of pain treatment. The most consistent finding is that depression and anxiety are associated with increased risk for drug abuse and decreased opioid efficacy. Discussion: The question remains whether the psychologic disorders antedated the pain condition or whether the experience of chronic pain exerts psychologic pressures that cause changes in behavior and psychologic processes. Additionally, the overall pattern suggests that younger age is predictive of opioid abuse and greater opioid efficacy. We also present a brief review of biologic mechanisms that support individual differences on opioid analgesia.

A previous meta-analysis of clinical analgesic trial studies showed generally low magnitudes of placebo analgesia (N. Engl. J. Med. 344 (2001) 1594). However, as studies included in their analysis used only placebo as a control condition, we conducted two meta-analyses, one in which 23 studies used only placebo as a control condition, and one in which 14 studies investigated placebo analgesic mechanisms. Magnitudes of placebo analgesic effects were much higher in the latter (mean effect size=0.95) as compared to the former (mean effect size=0.15) and were significantly different (P=0.003). This difference as well as differences in effect sizes within studies of placebo mechanisms may be parsimoniously explained by differences in expected pain levels produced by placebo suggestions and by conditioning. Furthermore, some of the studies of placebo analgesic mechanisms indicate that the magnitude of placebo analgesia is higher when the placebo analgesic effect is induced via suggestion combined with conditioning than via suggestion alone or conditioning alone. Based on these findings, we suggest that placebo analgesic effects are most optimally conceptualized in terms of perception of the placebo agent, and therefore a new definition of placebo response is proposed.

This study investigated sex and age cohort differences in the subjective report of orofacial pain symptoms in a stratified sample of community dwelling adults. The subjects were 724 participants in the Florida Dental Care Study, a longitudinal study of oral health among dentate adults, age 45 and older at baseline. Pain prevalence and subjective ratings were assessed for a range of orofacial pain sites using a standardized telephone interview. The results suggest that the 6-month prevalence of jaw joint pain (8.3%), face pain (3.1%), toothache pain (12.0%), painful oral sores (15.6%), and burning mouth (1.6%) found in the FDCS sample are similar to United States population estimates. In addition, prevalence for pain when chewing and temperature sensitivity were also reported as 23% and 24% respectively, suggesting that these two seldom documented painful experiences are common. Female respondents reported higher 6-month prevalence for multiple symptoms and painful oral sores, with trends also observed for female sex as a risk factor for jaw joint pain and face pain, whereas males were more likely to report temperature sensitivity. A higher percentage of females rated their pain as severe enough to impact behavior for jaw joint pain, toothache pain, and painful oral sores. Few overall age effects were found, with the exception of higher prevalence of temperature sensitivity and pain when chewing in the 45--64-year-old group, compared to respondents in the 65+ age cohort. However, the most interesting finding was that when sex by age cohort comparisons were made, with the exception of painful oral sores, all significant differences in pain ratings were found within the 45--64-year-old cohort and not the 65+ group. This finding clarified inconsistencies found in earlier studies in the orofacial pain literature where sex differences in pain ratings were found in several adult samples of a wide range of ages but not in a sample of older adults.

Objective: The goal of this study was to examine the relative importance of global affective distress, self-report of depressive symptoms, and presence or absence of major depression to the experience of chronic pain. Setting: A multidisciplinary pain program at a university medical center was the setting for this study. Patients: Subjects in this study were 211 consecutive patients with chronic pain. Outcome Measures: Pain duration, compensation, and litigation status were controlled for in the statistical analyses, as each correlated significantly with at least one of the measures of affect. Global affective distress was assessed using the Global Severity Index (GSI) from the Brief Symptom Inventory. The Beck Depression Inventory and the Center for Epidemiological Studies Depression Scale were used as measures of self-report of depressive symptoms. Presence or absence of major depression was based on DSM-IV criteria. Results and Conclusions: The GSI, Beck Depression Inventory, and Center for Epidemiological Studies Depression Scale were significantly correlated with each measure of the experience of pain, although clinical depression was only significantly related to self-reported disability and negative thoughts about pain. The self-report measures of depression maintained their relation to the dependent measures when the somatic items from the scales were removed, suggesting that the relations were not spuriously due to the influence of pain symptoms on the scales. When examining the unique contribution of each variable to the experience of pain (by simultaneously controlling for the other measures of affect), the GSI was uniquely related to the sensory and affective components of pain. Self-report of depressive symptoms was more highly related to a measure of the evaluative component of pain and uniquely related to self-reported disability and negative thoughts about pain. The results are discussed within the context of theoretical models of the relation between pain and affect, and suggestions for future research are presented.

The purpose of this study was to determine which specific attributes of painful orofacial symptoms serve as predictors of health care utilization in a population based sample of elderly subjects. Furthermore, we documented patterns of health care utilization selection by type of health care provider. To our knowledge, these specific utilization patterns have never before been reported in the pain literature. Telephone interviews were conducted with a stratified random sample of 1636 community dwelling older (65+) north Floridians. A total of 5860 households were contacted and screened, with 75.3% participating to the point where their eligibility for the study could be determined. The percentage of subjects reporting health care utilization for a specific symptom ranged from 62 to 32%. One or more health care visits were reported by at least 50% of those reporting symptoms of toothache pain, facial pain, jaw joint pain and burning mouth in the past 12 months. These rates suggest that elderly individuals are willing and able to seek health care for painful orofacial symptoms. We found that pain intensity was the best predictor of whether an elderly individual utilized health care or not, which suggests that some pain intensity threshold may exist at which health care seeking behavior is initiated. The overall number of visits was not predicted by pain intensity but by other qualities more associated with time or level of dysfunction caused by the symptom. We also found that elderly adults, typically seek care for toothache from a dentist and from physicians for painful orofacial symptoms not associated with the teeth or mouth. These decisions regarding the selection of a health care professional may, in part, be a function of financial and insurance considerations, anatomical site and perception of the role of dentistry in orofacial care.

Objective: To show clinical utility and empirical validity of Minnesota Multiphasic Personality Inventory-2 (MMPI-2) chronic pain patient subgroups by identification of differential multivariate relationships across groups. Method: This study used structural equation modeling to test cognitive coping strategies and somatization as mediator variables in path models with pain severity and depression used as exogenous (independent) variables and patient's activity level as the final endogenous (dependent variable, across MMPI-2 profiles. Results: Hierarchical cluster analysis, performed on a sample of 569 chronic low back patients, resulted in four cluster profiles identifiable as those found in previous work with the MMPI-2 (within normal limits, V-type, neurotic triad, and depressed-pathologica ) Somatization mediated the relationship between depression and activity level for the neurotic triad group but not the other three groups. A positive linear relationship was found between somatization and depression for the within normal limits, neurotic triad, and depressed-pathological groups, whereas their linear association was negative for the Vtype group. Cognitive coping strategies mediated the relationship between depression and activity level for the within normal limits group. In addition, cognitive coping was predictive of activity level for the within normal limits, V-type, and neurotic triad groups hut not for the depressed-pathologica group. Conclusion : Consistent with previous cluster analytic studies, this study replicated four MMPI-2 cluster profile groups in chronic pain patients. These results have also shown that several multivariate relationships between variables are different across MMPI-2 groups, providing evidence for the validity for these MMPI-2 subgroups.

The existing literature on experimentally induced pain indicates that there are sex differences, with females displaying greater sensitivity. In epidemiological studies, sex differences are also noted in the prevalence of a number of pain syndromes, with females reporting more severe pain, more frequent pain, and pain of longer duration. Complicating the interpretation of pain differences between men and women in clinical samples are reports of sex differences in response to pain-reducing medications. Studies in human subjects suggest that women respond better to certain opioid analgesics than men following third molar extraction, but few studies have assessed sex effects in effectiveness of topical anesthetics. The purpose of this study was to test for sex differences in response to a topical anesthetic, Lidocaine, using double blind, placebo controlled experimental methodology, in combination with a magnitude matching psychophysical protocol using a pressure algometer. The subjects were 21 female and 23 male adult volunteers. Twenty-four subjects (12 males and 12 females) were randomly assigned to the Lidocaine condition and 20 subjects were randomly assigned to the placebo control condition (9 males and 11 females). The effect size across sex for subjects in the Lidocaine treatment condition on the response bias variable was large indicating the males rated the stimuli as less painful than the females. Sex differences were not observed for discriminability in the Lidocaine treatment condition. This study did not show sex differences in the placebo condition. These results are particularly interesting in light of previous work that has shown similar pain stimuli (pressure pain) to be the stimulation most sensitive to sex differences. Results of this study suggest that the protocol employed (pressure pain stimulus with magnitude matching task) is sensitive to both anesthetic treatment and sex differences and represents an improvement in pain assessment methodology for use in experimental studies and in the clinic.

This study investigated sex differences in orofacial pain symptoms in a sample of elderly adults. Furthermore, differences across sex were tested on symptom continuity, overall duration, pain severity, activity reduction, and health care utilization, related to each specific symptom. Telephone interviews were conducted with a stratified random sample of community dwelling older (65+) north Floridians. A total of 5860 households were contacted and screened, with 75.3% participating to the point where their eligibility for the study could be determined. Of the remaining households, 1636 completed the interview. Of the total sample, 17.4% reported experiencing at least one of the four target orofacial pain symptoms (jaw joint pain, face pain, oral sores, burning mouth) during the past year, suggesting that orofacial pain symptoms are common in older adults. Our findings for prevalence of each specific symptom (jaw joint pain, 7.7%; face pain, 6.9%; oral sores, 6.4%; toothache, 12.0%; burning mouth, 1.7%) are similar to those estimated by the 1989 National Health Interview Survey, for the US adult population. Consistent with other epidemiological and clinical studies, we found that females were more likely to report jaw joint pain and face pain than males. In contrast to clinical studies, no differences were found on subjective ratings of pain severity, for any symptom. Differences across sex were most likely to be reported for jaw joint pain related variables, suggesting undetermined sex-uniqueness for these symptoms. In contrast to previous studies, older females tended to report lower levels of health care utilization than older males. This is the first study to our knowledge that reports orofacial symptom-specific sex differences among the elderly.

Fillingim and Maixner (Fillingim, R.B. and Maixner, W., Pain Forum, 4(4) (1995) 209-221) recently reviewed the body of literature examining possible sex differences in responses to experimentally induced noxious stimulation. Using a 'box score' methodology, they concluded the literature supports sex differences in response to noxious stimuli, with females displaying greater sensitivity. However, Berkley (Berkley, K.J., Pain Forum, 4(4) (1995) 225-227) suggested the failure of a number of studies to reach statistical significance suggests the effect may be small and of little practical significance. This study used meta-analytic methodology to provide quantitative evidence to address the question of the magnitude of these sex differences in response to experimentally induced pain. We found the effect size to range from large to moderate, depending on whether threshold or tolerance were measured and which method of stimulus administration was used. The values for pressure pain and electrical stimulation, for both threshold and tolerance measures, were the largest. For studies employing a threshold measure, the effect for thermal pain was smaller and more variable. The failures to reject the null hypothesis in a number of these studies appear to have been a function of lack of power from an insufficient number of subjects. Given the estimated effect size of 0.55 threshold or 0.57 for tolerance, 41 subjects per group are necessary to provide adequate power (0.70) to test for this difference. Of the 34 studies reviewed by Fillingim and Maixner, only seven were conducted with groups of this magnitude. The results of this study compels to caution authors to obtain adequate sample sizes and hope that this meta-analytic review can aid in the determination of sample size for future studies.

Objective: Past research has shown response biases to influence the accuracy of results from self-report measures. In pain assessment, where a percentage of patients have financial and other reasons to minimize or exaggerate psychological disturbance, it becomes especially important to identify the influence of response bias in self-report of adjustment. This study investigated the susceptibility of three commonly used self-report pain assessment measures to response bias. Design: This study used a within-subjects (asymptomatic subjects) design with two experimental conditions and nonequivalent control group (chronic pain patients). Subjects: Experimental group: 40 students enrolled in an occupational therapy program at a major southeastern United States university. Control group: 200 subjects referred to a multidisciplinary pain clinic at a major teaching hospital. Measures: Coping Strategies Questionnaire, Multidimensional Pain Inventory, and Pain Beliefs and Perceptions Inventory. Results: With few exceptions, asymptomatic subjects scored significantly differently on these measures while portraying themselves as either coping well or coping poorly. In addition, when using the "coping poorly" response set, asymptomatic subjects reproduced scores similar to those of symptomatic chronic pain patients. Conclusion: The susceptibility to manipulation appeared constant across the three measures, a finding that highlighted the difficulties clinicians and researchers encounter in accurate interpretation of results from these measures in the absence of validity indicators. This study also emphasizes the ease with which subjects with sufficient motivation can present themselves in an untruthful and manipulative manner and can generate scores that are, on their own, difficult to distinguish from those of a group of typical chronic pain patients.

The Coping Strategies Questionnaire (CSQ), a measure of coping in chronic pain patients, was subjected to item-level exploratory factor analysis.A sample of 965 chronic pain patients were used in the analysis.Principal components analysis using a varimax rotation procedure identified nine factors that accounted for 54.5% of the variance. Of these nine factors, the first five represent subscales of the original CSQ subscales. The catastrophizing subscale replicated with significant loadings for all six original items, and ignoring sensations replicated with five of six items. Factors representing reinterpreting pain sensations, coping self-statements, and diverting attention subscales also appeared. The items from the praying and hoping subscale split into separate praying and hoping factors (factors 6 and 8). When reliability coefficients were calculated, factors 7 through 9 had unacceptably low internal consistency and thus were not considered stable factors. Correlations between factors 1 through 6 and other measures of psychological and physical functioning were calculated in the construct validation portion of this study. Previously found relationships were replicated in that the correlations between CSQ factor scores and measures of pain, depression, and disability were in the same direction in this data set as those previously reported.