Psychometric properties of the 8-item Chronic Pain Acceptance Questionnaire (CPAQ-8) in a Swedish Chronic Pain Cohort

Background: Acceptance and Commitment Therapy for chronic pain has good empirical support. Pain acceptance is most often assessed with the Chronic Pain Acceptance Questionnaire (CPAQ). Recently a shorter 8-item version,the CPAQ-8, was developed.Objectives: To further validate the CPAQ-8 in a Swedish context and to test its sensitivity to treatment effects, an as-yet unknown property of the instrument.Methods: A total of 891 patients completed the CPAQ, along with scales for anxiety and depression (Hospital Anxiety and Depression scale), kinesiophobia (Tampa Scale for Kinesiophobia) and quality of life (Short Form-36). Confirmatoryfactor analyses were performed to examine the factor structure. Convergent validity was tested with Pearson’s correlations. Changes over time were evaluated with paired t-test.Results: The confirmatory factor analyses showed that the CPAQ 2-factor model had a better fit compared with the 1-factor model, both for the 8- and 20-item versions. All CPAQ-8 scales demonstrated good internal consistency (alpha≥ 0.80). They also correlated significantly with related constructs, supporting convergent validity. The CPAQ-8 explained a large share of the total variance in CPAQ-20 and was also able to track rehabilitation changes (large effectsize, d = 0.89).Conclusion: CPAQ-8 demonstrated good psychometric properties and sensitivity to rehabilitation changes. Further research that considers other cultural contexts may lead enhance the applications of this instrument

Psychometric properties of the 8-item Chronic Pain Acceptance Questionnaire (CPAQ-8) in a Swedish Chronic Pain Cohort

Background: Acceptance and Commitment Therapy for chronic pain has good empirical support. Pain acceptance is most often assessed with the Chronic Pain Acceptance Questionnaire (CPAQ). Recently a shorter 8-item version, the CPAQ-8, was developed. Objectives: To further validate the CPAQ-8 in a Swedish context and to test its sensitivity to treatment effects, an as-yet unknown property of the instrument. Methods: A total of 891 patients completed the CPAQ, along with scales for anxiety and depression (Hospital Anxiety and Depression scale), kinesiophobia (Tampa Scale for Kinesiophobia) and quality of life (Short Form-36). Confirmatory factor analyses were performed to examine the factor structure. Convergent validity was tested with Pearson's correlations. Changes over time were evaluated with paired t-test. Results: The confirmatory factor analyses showed that the CPAQ 2-factor model had a better fit compared with the 1-factor model, both for the 8- and 20-item versions. All CPAQ-8 scales demonstrated good internal consistency (alpha ≥ 0.80). They also correlated significantly with related constructs, supporting convergent validity. The CPAQ-8 explained a large share of the total variance in CPAQ-20 and was also able to track rehabilitation changes (large effect size, d = 0.89). Conclusion: CPAQ-8 demonstrated good psychometric properties and sensitivity to rehabilitation changes. Further research that considers other cultural contexts may lead enhance the applications of this instrument

Psychometric properties of Short Form-36 Health Survey, EuroQol 5-dimensions, and Hospital Anxiety and Depression Scale in patients with chronic pain

Recent research has highlighted a need for the psychometric evaluation of instruments targeting core domains of the pain experience in chronic pain populations. In this study, the measurement properties of Short Form-36 Health Survey (SF-36),EuroQol 5-dimensions (EQ-5D) and Hospital Anxiety and Depression Scale (HADS) were analyzed within the item response-theory framework based on data from 35,908 patients. To assess the structural validity of these instruments, the empirical representations of several conceptually substantiated latent structures were compared in a cross-validation procedure. The most structurally sound representations were selected from each questionnaire and their internal consistency reliability computed as a summary of their precision. Finally, questionnaire scores were correlated with each other to evaluate their convergent and discriminant validity. Our results supported that SF-36 is an acceptable measure of 2 independent constructs of physical and mental health. By contrast, although the approach to summarize the health-related quality of life construct of EQ-5D as a unidimensional score was valid, its low reliability rendered practical model implementation of doubtful utility. Finally, rather than being separated into 2 subscales of anxiety and depression, HADS was a valid and reliable measure of overall emotional distress. In support of convergent and discriminant validity, correlations between questionnaires showed that theoretically similar traits were highly associated, whereas unrelated traits were not. Our models can be applied to score SF-36 and HADS in chronic pain patients, but we recommend against using the EQ-5D model due to its low reliability. These results are useful for researchers and clinicians involved in chronic pain populations because questionnaires' properties determine their discriminating ability in patient status assessment

Sick Leave Before and After Diagnosis of Rheumatoid Arthritis - A Report from the Swedish TIRA Project

Objective. Our study describes sick leave during 3 years before and 3 years after diagnosis of rheumatoid arthritis (RA) in relation to referents and identifies predictors for sick leave during the third year after diagnosis of RA. Methods. One hundred twenty patients (76% women) from the Swedish early RA study TIRA were included. Disease activity and disability were registered regularly during 3 years in TIRA. Referents were matched for sex, age, and home town. Sick leave data were obtained for patients 3 years before and 3 years after diagnosis and for the referents for the corresponding 6 years. Results. No differences were seen between patients and referents regarding sick leave during the first 2 years, whereas sick leave increased in patients 6 months before diagnosis, from 30% to 53%. During the 3 years after diagnosis, sick leave among patients was rather stable, varying between 50% and 60%, even though disability pension increased and sickness benefit decreased. Sick leave before diagnosis, disability I year after diagnosis, and type of work were identified as predictors for sick leave during the third year after diagnosis. Conclusion. Not surprisingly, sick leave in patients increased the year before diagnosis. Although disease activity and disability diminished after diagnosis, the patients' sick leave remained essentially unchanged. Sick leave 3 years after diagnosis was foremost predicted by earlier sick leave, disability, and type of work. (First Release May 1 2009; J Rheumatol 2009:36:1170-9; doi:10.3899/jrheum.080523

Identification of Proteins from Interstitium of Trapezius Muscle in Women with Chronic Myalgia Using Microdialysis in Combination with Proteomics

Background: Microdialysis (MD) of the trapezius muscle has been an attractive technique to investigating small molecules and metabolites in chronic musculoskeletal pain in human. Large biomolecules such as proteins also cross the dialysis membrane of the catheters. In this study we have applied in vivo MD in combination with two dimensional gel electrophoresis (2-DE) and mass spectrometry to identify proteins in the extracellular fluid of the trapezius muscle. Materials and Methods: Dialysate from women with chronic trapezius myalgia (TM; n = 37), women with chronic wide spread pain (CWP; n = 18) and healthy controls (CON; n = 22) was collected from the trapezius muscle using a catheter with a cut-off point of 100 kDa. Proteins were separated by two-dimensional gel electrophoresis and visualized by silver staining. Detected proteins were identified by nano liquid chromatography in combination with tandem mass spectrometry. Results: Ninety-seven protein spots were identified from the interstitial fluid of the trapezius muscle; 48 proteins in TM and 30 proteins in CWP had concentrations at least two-fold higher or lower than in CON. The identified proteins pertain to several functional classes, e. g., proteins involved in inflammatory responses. Several of the identified proteins are known to be involved in processes of pain such as: creatine kinase, nerve growth factor, carbonic anhydrase, myoglobin, fatty acid binding protein and actin aortic smooth muscle. Conclusions: In this study, by using in vivo microdialysis in combination with proteomics a large number of proteins in muscle interstitium have been identified. Several of the identified proteins were at least two-fold higher or lower in chronic pain patients. The applied techniques open up for the possibility of investigating protein changes associated with nociceptive processes of chronic myalgia

The Effect of Microdialysis Catheter Insertion on Glutamate and Serotonin Levels in Masseter Muscle in Patients with Myofascial Temporomandibular Disorders and Healthy Controls

Myofascial temporomandibular disorders (TMD) are the most common cause of chronic pain in the orofacial region. Microdialysis has been used to study metabolic changes in the human masseter muscle. The insertion of the microdialysis probe causes acute tissue trauma that could affect the metabolic milieu and thereby influence the results when comparing healthy subjects to those with TMD. This study aimed to investigate the levels of serotonin and glutamate during the acute tissue trauma period in healthy subjects and in patients with TMD. Microdialysis was carried out in 15 patients with TMD and 15 controls, and samples were collected every 20 min during a period of 140 min. No significant alterations of serotonin or glutamate were observed over the 2 h period for the healthy subjects. For the TMD group, a significant decrease in serotonin was observed over time (p < 0.001), followed by a significant increase between 120 and 140 min (p < 0.001). For glutamate, a significant reduction was observed at 40 min compared to baseline. The results showed that there was a spontaneous increase of serotonin 2 h after the insertion of the catheter in patients with TMD. In conclusion, the results showed that there are differences in the masseter muscle levels of serotonin and glutamate during acute nociception in patients with myofascial TMD compared to healthy subjects

Ehlers-Danlos Syndrome and Hypermobility Syndrome Compared with Other Common Chronic Pain Diagnoses-A Study from the Swedish Quality Registry for Pain Rehabilitation

Although chronic pain is common in patients with Ehlers-Danlos syndrome (EDS) and hypermobility syndromes (HMS), little is known about the clinical characteristics of these groups. The main aim was to compare EDS/HMS with common local and generalized pain conditions with respect to Patient Reported Outcome Measures (PROMs). Data from the Swedish Quality Register for Chronic Pain (SQRP) from 2007 to 2016 (n= 40,518) were used, including patients with EDS/HMS (n= 795), fibromyalgia (n= 5791), spinal pain (n= 6693), and whiplash associated disorders (WAD) (n= 1229). No important differences in the PROMs were found between EDS and HMS. Women were represented in > 90% of EDS/HMS cases and fibromyalgia cases, and in about 64% of the other groups. The EDS/HMS group was significantly younger than the others but had a longer pain duration. The pain intensity in EDS/HMS was like those found in spinal pain and WAD; fibromyalgia had the highest pain intensity. Depressive and anxiety symptoms were very similar in the four groups. Vitality-a proxy for fatigue-was low both in EDS/HMS and fibromyalgia. The physical health was lower in EDS/HMS and fibromyalgia than in the two other groups. Patients with EDS/HMS were younger, more often female, and suffered from pain for the longest time compared with patients who had localized/regional pain conditions. Health-care clinicians must be aware of these issues related to EDS/HMS both when assessing the clinical presentations and planning treatment and rehabilitation interventions

http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-20186 BMC Musculoskeletal Disorders

Physiological responses to low-force work and psychosocial stress in women with chronic trapezius myalgi