Does past/current pain change pain experience? Comparing self-reports and pupillary responses.

Introduction: For decades, a substantial body of research has confirmed the subjective nature of pain. Subjectivity seems to be integrated into the concept of pain but is often confined to self-reported pain. Although it seems likely that past and current pain experiences would interact and influence subjective pain reports, the influence of these factors has not been investigated in the context of physiological pain. The current study focused on exploring the influence of past/current pain on self-reporting and pupillary responses to pain. Methods: Overall, 47 participants were divided into two groups, a 4°C-10°C group (experiencing major pain first) and a 10°C-4°C group (experiencing minor pain first), and performed cold pressor tasks (CPT) twice for 30 s each. During the two rounds of CPT, participants reported their pain intensity, and their pupillary responses were measured. Subsequently, they reappraised their pain ratings in the first CPT session. Results: Self-reported pain showed a significant difference (4°C-10°C: p = 0.045; 10°C-4°C: p < 0.001) in the rating of cold pain stimuli in both groups, and this gap was higher in the 10°C-4°C group than in the 4°C-10°C group. In terms of pupillary response, the 4°C-10°C group exhibited a significant difference in pupil diameter, whereas this was marginally significant in the 10°C-4°C group (4°C-10°C: p < 0.001; 10°C-4°C: p = 0.062). There were no significant changes in self-reported pain after reappraisal in either group. Discussion: The findings of the current study confirmed that subjective and physiological responses to pain can be altered by previous experiences of pain.

Characteristics of Diverse Verbal Pain Descriptors in South Korean Patients With Peripheral Neuropathic Pain: 'Jeorim' (Tingling) and 'Sirim' (Cold) as Key Neuropathic Pain Descriptors.

BACKGROUND AND PURPOSE: The description of pain is the most-important indicator leading to the adequate treatment of patients with neuropathic pain (NeP). The purpose of this study was to identify and characterize the unique features of Korean verbal descriptions in patients with peripheral NeP. METHODS: This study included 400 patients (167 males and 233 females) and their 1,387 pain-description responses. Patients with peripheral NeP freely described their symptoms in Korean. Collected verbal descriptions were grouped according to terminologies with similar meanings. Participants completed validated patient-reported outcome scales including the neuropathic pain symptom inventory (NPSI) and painDETECT questionnaire (PD-Q). The frequencies of each verbal pain descriptor were compared between the NPSI and PD-Q scores. RESULTS: 'Jeorim' (tingling) was the most common among 17 types of organized verbal pain descriptors, and the 'Sirim' (cold) symptom had a significantly higher rate of use in the 2 high-severity groups when participants were classified by their total scores on the NPSI and PD-Q. CONCLUSIONS: Korean verbal NeP descriptors were significantly diverse. The Jeorim (tingling) and Sirim (cold) descriptors can be utilized in evaluations of Korean patients with NeP.

Enhanced supportive care for advanced cancer patients: study protocol for a randomized controlled trial.

BACKGROUND: Early palliative care along with standard cancer treatments is recommended in current clinical guidelines to improve the quality of life and survival of cancer patients. This study protocol aims to evaluate the effect of "Enhanced Supportive Care", an early primary palliative care provided by nurses. METHODS: A randomized controlled trial (RCT) will be conducted including advanced cancer patients scheduled for first-line palliative chemotherapy (N=360) and their caregivers in South Korea. Participants will be randomly assigned to the intervention or control group in a 1:1 ratio. Participants in the intervention group will receive the "Enhanced Supportive Care", which provides five sessions of symptom management and coping enhancement counseling by nurses. The control group will receive symptom monitoring five times. The primary endpoints are symptoms, coping, and quality of life (QoL) at 3 months. Secondary endpoints are symptoms, coping, and QoL at 6 months, depression and self-efficacy for coping with cancer at 3 and 6 months, symptom and depression change from baseline to 3 months, survival at 6 and 12 months among patients, and depression among caregivers at 3 and 6 months. DISCUSSION: This RCT will evaluate the effects of "Enhanced Supportive Care" on symptoms, depression, coping, self-efficacy for coping with cancer, QoL and survival of patients, as well as depression of caregivers. It will provide evidence of a strategy to implement early primary palliative care provided by nurses, which may consequently improve cancer care for newly diagnosed patients with advanced stage cancer. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04407013. Registered on May 29, 2020, https://www. CLINICALTRIALS: gov/ct2/show/study/NCT04407013 . The protocol version is ESC 1.0.

Role of affective instability on suicidal risk in complex regional pain syndrome: a diary approach (preliminary report).

BACKGROUND: Many patients with complex regional pain syndrome (CRPS) have been known to be at risk of suicide, due to severe pain and its comorbid conditions. The risk of suicide may be associated with affective instability, which is an indicator of emotional dysregulation. Particularly, unstable shifts in negative emotions are difficult to cope with, which may result in individuals feeling uncontrollable, hopeless, and entrapped. This study aimed to examine the role of affective instability in the relationship between pain intensity and suicide risk (suicidal ideation and impulsivity) in patients with CRPS, by employing a daily diary. METHODS: Twenty-three patients registered at the CRPS Association in Korea were asked to complete a day-to-day routine for 15 days, followed by a diary composed of pain intensity, suicidal ideation, impulsivity, and positive and negative affects. RESULTS: Results showed that the interactions between negative affective instability and daily pain intensity were statistically significant on daily suicidal ideation (coefficient = 0.41, t (21) = 2.56, P < 0.050) and daily impulsiveness (coefficient = 1.20, t (19) = 3.35, P < 0.010). However, those between positive affective instability and daily pain intensity were not. CONCLUSIONS: This study is the first attempt to investigate the role of affective instability on the relationship between daily pain intensity and daily suicide risk in patients with CRPS. Our findings suggest that health professionals pay considerable attention to the instability of negative affects when assessing and managing patients with CRPS at risk of suicide.

Efficacy of Interpretation Bias Modification in Patients With Chronic Pain.

Patients with chronic pain demonstrate interpretational bias to pain, and models of pain suggest interpretational bias affects subsequent pain experience. This study developed an interpretation bias modification for pain (IBM-P) and examined its efficacy. A total of 48 patients with chronic pain were recruited and randomly assigned to either the training group (n = 24) or the control group (n = 24). Interpretational bias, negative emotions, and attentional bias to pain-related stimuli were assessed before and after conducting IBM-P. The main results indicated that the training group showed less interpretational bias and negative emotions after IBM-P than the control group. The training group also gazed at neutral words longer than at "new" affective pain words after IBM-P than they did prior to the intervention. Furthermore, significant mediating effects of postinterpretational bias were found in the relationship between the group type and postnegative emotions and postdwell time bias. These results suggest that IBM-P can modify interpretational bias which leads to changes in negative emotions and attentional bias. Future research is needed to confirm the effect of modifying interpretational bias and its clinical utility in the field of pain management. PERSPECTIVE: This article investigated the efficacy of IBM-P and suggested that modifying interpretational bias is followed by changes in negative emotions and attentional bias. These findings may help health professionals understand the role of interpretational bias in chronic pain and encourage the potential use of IBM in pain management.

Validation of the Korean version of the avoidance endurance behavior questionnaire in patients with chronic pain.

BACKGROUND: The avoidance-endurance model suggests both fear-avoidance responses and endurance-related responses could affect the chronicity of pain. Proper pain intervention requires measuring fear-avoidance responses and endurance-related responses but no Korean language questionnaire has yet been made to measure them. The purpose of this study was to evaluate the validity and reliability of the Korean version of the Avoidance-Endurance Behavior Questionnaire (K-AEQ-Behavior) by adapting the behavioral responses of Avoidance-Endurance Questionnaire into Korean language. METHODS: The K-AEQ-Behavior was forward and backward translated based on the standards for instrument translation. A total of 136 outpatients with chronic pain of a duration exceeding 3 months were recruited from a pain center at a university hospital in Seoul, Korea. Two weeks later, the K-AEQ-Behavior was re-administered to 36 patients for test-retest reliability. Exploratory factor analysis was performed using principle axis factoring. The internal consistency, test-retest reliability, and concurrent validity of the K-AEQ-Behavior were measured by Cronbach's ⍺, intraclass correlation coefficient, and Pearson correlation coefficient, respectively. RESULTS: Although the four-factor structure (23 items) was derived in the original study, the two-factor structure of avoidance behavior and endurance behavior (21 items) was derived in the exploratory factor analysis of the Korean version in this study. Other results indicated that K-AEQ-Behavior has good internal consistency, test-retest reliability and concurrent validity. CONCLUSION: This study suggests that the K-AEQ-Behavior is a reliable and valid instrument for assessing avoidance behavior and endurance behavior in patients with chronic pain.

Depressive symptoms following natural disaster in Korea: psychometric properties of the Center for Epidemiologic Studies Depression Scale.

BACKGROUND: Depressive symptoms have been recognized as one of the most frequent complaints among natural disaster survivors. One of the most frequently used self-report measures of depressive symptoms is the Center for Epidemiologic Studies Depression Scale (CES-D). To our knowledge, no study has yet examined the factor structure, reliability, and validity of the CES-D in a sample of natural disaster survivors. Thus, the present study investigated the factor structure, reliability, and validity of a Korean language version of the CES-D (KCES-D) for natural disaster survivors. METHODS: We utilized two archived datasets collected independently for two different periods in 2008 in the same region of Korea (n = 192 for sample 1; n = 148 for sample 2). Participants were survivors of torrential rains in the mid-eastern region of the Korean peninsula. For analysis, Samples 1 and 2 were merged (N = 340). Confirmatory factor analysis was performed to evaluate the one-factor model, the four-factor model, and the bi-factor models, as well as the second-order factor model. Composite reliability was computed to examine the internal consistency of the KCES-D total and subscale scores. Finally, Pearson's r was computed to examine the relationship between the KCES-D and the trauma-related measures. RESULTS: The four-factor model provided the best fit to the data among the alternatives. The KCES-D showed adequate internal consistency, except for the 'interpersonal difficulties' subscale. Also regarding concurrent validity, weak to moderate positive correlations were observed between the KCES-D and the trauma-related measures. CONCLUSIONS: The results support the four-factor model and indicate that the KCES-D has adequate psychometric properties for natural disaster survivors. If these findings are further confirmed, the KCES-D can be used as a useful, rapid, and inexpensive screening tool for assessing depressive symptoms in natural disaster survivors.

Assessing psychological flexibility in patients with chronic pain: the Korean adaptation of the Brief Pain Response Inventory.

PURPOSE: This study investigated the psychometric properties of the Korean version of the Brief Pain Response Inventory (K-BPRI) regarding patients with chronic pain. METHODS: This study employed a retrospective survey design. One hundred sixty-four Korean patients with chronic pain participated in the study. Construct validity was assessed using confirmatory factor analysis and Pearson correlation. Internal consistency reliability, test-retest reliability, and measurement error were examined using Cronbach's α, the inter-item correlation coefficients, and the item-total correlation coefficients; the intra-class correlation coefficient; and the standard error of measurements, respectively. RESULTS: Confirmatory factory analysis showed the best fit to the data for the adjusted two-factor structure of the K-BPRI. The K-BPRI demonstrated good internal consistency and test-retest reliability. Measurement errors for the K-BPRI and subscale scores were standard error of measurements = 5.74, 5.63, and 10.26, respectively, and minimum detectable change = 15.86, 15.56, and 28.35, respectively. Weak-to-moderate negative correlations were observed between the K-BPRI and the numerical rating scale for pain intensity and the Hospital Anxiety Depression Scale, and moderately positive correlations were observed between the K-BPRI and Short Form-12. CONCLUSION: This study provided evidence for the psychometric properties of the K-BPRI, suggesting that it can be a brief and efficient instrument for measuring psychological flexibility in coping with chronic pain.

Acceptance and patient functioning in chronic pain: the mediating role of physical activity.

PURPOSE: Activity engagement, which refers to pursuing activities despite pain, is conceptually related to pain acceptance. A recent diary study suggested that pain acceptance precedes and directly influences physical activity, and thus, pain acceptance appears to be an important aspect of eliciting better functioning by allowing patients with chronic pain (PCPs) to participate in physical activity despite the pain. This retrospective, cross-sectional cohort study was conducted to investigate the mediating effect of physical activity on the association between pain acceptance and functioning and the association between physical activity level and functioning in PCPs. METHODS: The study participants were 176 patients seeking treatment for chronic pain at a tertiary pain center in Korea. The Chronic Pain Acceptance Questionnaire, International Physical Activity Questionnaire-Short Form, and Short Form-36 were used to assess pain acceptance, physical activity, and patient functioning. The mediating effects of physical activity were tested using procedures described by Baron and Kenny. Also, three hierarchical multiple linear regression analyses were conducted to identify levels of physical activity that predict measures of patient functioning. RESULTS: Physical activity partially mediated the association between pain acceptance and patient functioning except for pain intensity. Furthermore, walking and moderate activity were found to be associated with improvements in all areas of patient functioning except for pain intensity. CONCLUSION: To improve the functioning of PCPs, health professionals may need to help patients accept private experiences related to pain and plan activity pacing programs that focus on value-based activities.

The Effects of Long-Term Ketamine Treatment on Cognitive Function in Complex Regional Pain Syndrome: A Preliminary Study.

OBJECTIVE: This preliminary study aimed to investigate the effects of long-term frequent ketamine treatment on cognitive function in [AQ-A] CRPS patients. DESIGN: A total of 30 CRPS patients were divided into two groups based on both the duration and frequency of ketamine treatment; the long-term frequent ketamine treatment (LF) group (N = 14) and the Non-LF group (N = 16). Participants were asked to complete a questionnaire packet including demographic and clinical characteristics and potential variables affecting cognitive function. Then, they performed the neuropsychological test. RESULTS: Results indicated that the LF group performed significantly poorer than the Non-LF group on the digit span, digit symbol, Controlled Oral Word Association Test, and Trail Making Test, but not the Stroop task. CONCLUSIONS: Patients with CRPS receiving long-term frequent ketamine treatment showed impairment in cognitive function (specifically executive function) compared with those who do not. These findings may have implications for clinical assessment and rehabilitation of cognitive function in CRPS patients.

Confirmatory factor analysis of the Korean version of the short-form McGill pain questionnaire with chronic pain patients: a comparison of alternative models.

BACKGROUND: The Short Form of the McGill Pain Questionnaire (SF-MPQ) is the most widely used assessment of the quality and intensity of pain. In previous validation studies, the factor structure of the SF-MPQ varied widely from various two-factor structures to a five-factor structure, although research on the SF-MPQ quite consistently supports its two-factor structure (i.e., sensory and affective) across different countries and languages. In Korea, the results of exploratory factor analysis of a Korea version of SF-MPQ (KSF-MPQ) showed 2-factor structure consisting of 'sensory' and 'affective' excluding two items such as splitting and heavy. As an attempt to further validate the KSF-MPQ, the purpose of this study was to confirm whether the KSF-MPQ model is an appropriate model for chronic pain patients in Korea by comparing several alternative models of the SF-MPQ. FINDINGS: A total of 150 chronic pain patients seeking treatment in Seoul, Korea, participated and completed the KSF-MPQ. Confirmatory factor analysis was conducted to evaluate the adequacy of the KSF-MPQ model and several alternative models. The results indicated that the adjusted KSF-MPQ model showed the best fit to the data among the models in chronic pain patients in Korea. CONCLUSIONS: The results showed the KSF-MPQ is cross-culturally equivalent to the original questionnaire. Thus, the KSF-MPQ is valid measurement for assessing the quality and intensity of pain to chronic pain patients and may be helpful in clinical and research settings in Korea.

Assessment of factors affecting the difficulty of caudal epidural injections in adults using ultrasound.

BACKGROUND: In unaided caudal epidural block (CEB), incorrect needle insertion has been reported to occur in 15% to 38% of attempts. OBJECTIVE: To statistically analyze the anatomical variables affecting difficult CEB using ultrasonographic measurement. METHODS: Preprocedural ultrasonography was performed and the following measurements were obtained in 146 patients: the distance from the skin to the apex of the sacral hiatus; the depth of the sacral canal at the apex of the sacral hiatus; the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base; the distance from the skin to the apex of the sacral cornu; and the distance between the apexes of bilateral cornua. One clinician, unaware of the ultrasonographic findings, performed the injections using the landmark technique. The procedures were videotaped and were subsequently reviewed by an independent investigator. RESULTS: The means (± SDs) of the abovementioned measurements were 12.1±3.7 mm, 6.1±2.1 mm, 25.9±7.4 mm, 10.0±4.0 mm and 16.4±3.2 mm, respectively. Injections failed in 16 (11%) patients and were defined as difficult in 21 (14.4%) patients. The depth of the sacral canal at the apex of sacral hiatus (P<0.001) and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base (P=0.001) were significant predictors of difficult CEB. Of all patients, 85.7% and 75.2% were correctly classified as difficult or not difficult, respectively. The cutoff values of the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and the sacral base to predict a difficult CEB were 3.7 mm and 17.6 mm, respectively. CONCLUSIONS: Both the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base are significant variables affecting the difficulty of the CEB.

Application of virtual body swapping to patients with complex regional pain syndrome: a pilot study.

This study aimed to apply virtual body swapping through mental rehearsal for patients with complex regional pain syndrome (CRPS) and to investigate whether it is applicable to them. Ten patients who met the diagnostic criterion for CRPS type 1 were randomly assigned to either the treatment or control group. All participants were asked to watch the virtual body swapping training video clip with a head mounted display. The treatment group was additionally asked to assume a posture similar to the body on the screen and rehearse the movements mentally, as if the body presented on the screen was their body. No difference between the groups was found for pain intensity, however, the treatment group showed significantly more improvement in body perception disturbance (BPD) after the treatment than the control group. Even if the presented study is a preliminary one, the above results suggest that virtual body swapping through mental rehearsal is applicable for patients with CRPS and may be useful for improving BPD. The limitations of the study and the future investigations needed to provide clearer clinical suggestions are presented and discussed.

The effect of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance in complex regional pain syndrome.

The present study investigated the effects of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance (BPD) in patients with complex regional pain syndrome. Patients with complex regional pain syndrome were assigned randomly to three experimental groups: the 'virtual body swapping with mental rehearsal' (VBS) group (n=13), the 'watching movement only' group (n=13), and the 'mental rehearsal only' (n=13) group. Then, pretreatment pain intensity and BPD were compared with post-treatment perceptions. The results showed that pain intensity did not decrease significantly after treatment in all of the groups. However, BPD improved significantly after treatment in the VBS group, but not in the other groups. Therefore, this study is the first to show the effects of a single session of VBS on BPD. Further studies should apply an elevated degree of immersion and create a more realistic virtual body.

Approach-avoidance pattern of visual attention in hazardous drinkers with ambivalence.

Ambivalence toward alcohol often develops when hazardous drinkers try to quit or to control their drinking. The purpose of this study was to investigate the differences between hazardous drinkers with and without ambivalence toward alcohol in terms of their visual attention to alcohol-related pictures over time using an eye-tracker. The study included 20 hazardous drinkers with ambivalence and 21 hazardous drinkers without ambivalence. The eye movements of the participants were monitored while the participants conducted a free-viewing task in which 20 pairs of alcohol-related pictures and matched control pictures were presented. The results showed that the hazardous drinkers with ambivalence were more attentive to the alcohol-related pictures at first and were more attentive to the control pictures toward the end of the task. On the other hand, the hazardous drinkers without ambivalence were more attentive to the alcohol-related pictures from beginning to end. The findings of this study indicated that ambivalence toward alcohol resulted in the inclination to approach and then avoid alcohol in a consecutive sequence. The present results could be helpful in distinguishing hazardous drinkers who may have ambivalence toward alcohol and identifying the pattern of ambivalence more concretely. Additionally, further studies need to consider the time that is important to measure ambivalence toward alcohol.

Psychometric evaluation of the sleep hygiene index: a sample of patients with chronic pain.

BACKGROUND: Sleep Hygiene Index (SHI) was designed to assess sleep hygiene. Although the SHI has shown adequate psychometric properties in a nonclinical sample, it has not been validated in a sample with chronic pain. Also, its factor structure, measurement error, and incremental validity over and above other factors affecting sleep quality have not been investigated in a nonclinical sample. Thus, this present study aimed to extend prior psychometric investigation of the SHI. Specifically, we evaluated the factor structure, measurement error, and incremental validity as well as the reliabilities and concurrent validity of the SHI in a sample with chronic pain. METHODS: A total of 161 patients seeking treatment in a tertiary pain center located in Seoul, Korea participated. To explore the factor structure of the SHI, we performed an exploratory factor analysis using principal component with varimax. Cronbach's alphas and intraclass correlation coefficients were computed to investigate internal consistency and 2-week test-retest stability of the SHI, respectively. Measurement error was estimated using standard error of measurement and minimum detectable change (MDC) of the SHI. For concurrent validity, Pearson correlations were calculated to examine the relations between the SHI and outcome measures including background variables. Also for incremental validity, a hierarchical multiple regression was performed in relation to sleep quality. RESULTS: Results indicated that two-factor solution is most appropriate; sleep disturbing behavior and environment (B/E) and irregular sleep-wake schedule. Results also showed that the internal consistencies and test-retest stability estimates of the SHI were deemed acceptable. At the 95% confidence level, the MDCs were 5.75 for 'sleep disturbing B/E,' 3.65 for 'irregular sleep-wake schedule,' and 7.49 points for total. The SHI was significantly correlated with age, depression, pain-related anxiety, and sleep quality. Also, sleep quality was significantly predicted by the irregular sleep-wake schedule subscale of the SHI, over and above background variables, pain intensity, depression, pain-related anxiety. CONCLUSIONS: The SHI has the reliability, measurement error, and concurrent and incremental validity support for assessing sleep hygiene in a sample with chronic pain.

Effects of the combination of P3-based GKT and reality monitoring on deceptive classification.

The study aimed to investigate whether a combination of the P3-based Guilty Knowledge Test (GKT) and reality monitoring (RM) distinguished between individuals who are guilty, witnesses, or informed, and using both tests provided more accurate information than did the use of either measure alone. Participants consisted of 45 males that were randomly and evenly assigned to three groups (i.e., guilty, witness, and informed). The guilty group conducted a mock crime where they intentionally crashed their vehicle into another vehicle in a virtual environment (VE). As those in the witness group drove their own vehicles, they observed the guilty groups' vehicle crash into another vehicle. The informed group read an account and saw screenshots of the accident. All participants were instructed to insist that they were innocent. Subsequently, they performed the P3-based GKT and wrote an account of the accident for the RM analysis. A higher P3 amplitude corresponded to how well the participants recognized the presented stimulus, and a higher RM score corresponded to how well the participants reported vivid sensory information and how much less they reported uncertain information. Findings for the P3-based GKT indicated that the informed group showed lower P3 amplitude when presented with the probe stimulus than did the guilty and witness groups. Regarding the RM analysis, the informed group obtained higher RM scores on visual, temporal, and spatial details and lower scores on cognitive operations than the guilty and witness groups. Finally, discriminant analysis revealed that the combination of the P3-based GKT and RM more accurately distinguished between the three groups than the use of either measure alone. The findings suggest that RM may build upon a weakness of the P3-based GKT's. More specifically, it may build upon its susceptibility to the leakage of information about the crime, therefore helping protect innocent individuals who have information about a crime from being perceived as guilty.

Pain acceptance-based coping in complex regional pain syndrome Type I: daily relations with pain intensity, activity, and mood.

This study aimed to examine the temporal patterning of pain acceptance-based coping, activity, and mood in patients with complex regional pain syndrome Type I (CRPS-I), by using a daily diary method. A total of 30 patients with CRPS-I seeking treatment in a tertiary pain management center located in Seoul, Korea participated in the study. Multilevel random effects analyses indicated that (a) engagement in pain acceptance-based coping was significantly associated with lower same-day pain and negative mood and greater same-day activity and positive mood; (b) pain acceptance-based coping predicted increases in activity on the following day; (c) greater pain intensity was significantly associated with lower same-day pain acceptance-based coping and activity and greater same-day negative mood; and (d) pain intensity did not predict pain acceptance-based coping, activity, or mood on the following day. These findings suggest that patients with CRPS-I may benefit from responding to pain with acceptance. Further study and eventual application of this process in CRPS-I may improve upon the success of current approaches to this problem.

Validation of the Korean version of the Pain Catastrophizing Scale in patients with chronic non-cancer pain.

PURPOSE: Pain catastrophizing often has been measured using the Pain Catastrophizing Scale (PCS). Studies of the PCS nearly consistently support its three-factor structure (i.e., helplessness, magnification, and rumination) and satisfactory psychometric properties across different countries and languages. This study aimed to assess the generalizability of the three-factor structure of the PCS to Korean patients with chronic non-cancer pain and to investigate reliability, measurement error, and construct validity of a Korean version of the PCS (K-PCS). METHODS: A total of 182 patients with chronic pain seeking treatment in a tertiary pain center located in Seoul, Korea, participated. RESULTS: Confirmatory factor analysis demonstrated the adequacy of the three-factor structure of the K-PCS; 'helplessness,' 'magnification,' and 'rumination.' The internal consistency for 'helplessness,' 'magnification,' 'rumination,' and total scale of the K-PCS were Cronbach's α = .90, .71, .86, and .93, respectively; test-retest stability, ICC = .77, .73, .65, and .79, respectively; the standard estimation of measurement, 1.93, 1.34, 2.13, and 3.72, respectively; the minimum detectable change, 5.33, 3.70, 5.89, and 10.28, respectively; and the limits of agreement, -7.66 to 9.20, -5.07 to 5.01, -7.30 to 6.86, and -15.26 to 16.46, respectively. At least moderate positive correlations were observed between the K-PCS and pain intensity, depression, and pain-related anxiety, and moderate negative correlations between the K-PCS and physical and psychological functioning. CONCLUSION: The K-PCS has the reliability, measurement error, and construct validity support for assessing pain catastrophizing in a Korean patient sample with chronic non-cancer pain.

Effects of pain controllability and discrepancy in social support on depressed mood among patients with chronic pain.

BACKGROUND: Preference of types of social support may vary across recipients, and social support that is less than the amount preferred may be associated with depressed mood. PURPOSE: This study aimed to investigate the interaction effects between pain controllability and discrepancy in social support and the additive utility of discrepancy in social support over perceived social support in predicting depressed mood among patients with chronic pain. METHOD: A total of 173 patients seeking treatment at two outpatient pain management clinics in Hawaii participated. RESULTS: The results indicated that (1) patients with low pain controllability preferred significantly more social support than those with high pain controllability, for all types of social support; (2) patients preferred significantly more informational and emotional support than instrumental support for both pain controllability levels; (3) discrepancy in informational or instrumental support was not associated with depressed mood, whereas discrepancy in emotional support was significantly associated with more depressed mood for low pain controllability, but not for high pain controllability; and (4) discrepancy in emotional support added a significant increment of variance in predicting depressed mood over and above perceived emotional support, whereas discrepancy in informational or instrumental support did not. CONCLUSION: Findings suggest the relative importance of discrepancy in emotional support from a significant other, especially for patients with low pain controllability.