Does a combination of self-reported signs related to central sensitization and pressure pain threshold allow for a more detailed classification of pain-related characteristics in patients with chronic musculoskeletal pain?: A cross-sectional study.

OBJECTIVES: The clinical utility of combining the central sensitization (CS) inventory (CSI) with the pressure pain threshold (PPT) in assessing the effect of central sensitization on pain is unknown. This study aimed to investigate the effects of CSI, PPT, and their interaction on pain and the characteristics of clinical symptoms in patients with chronic musculoskeletal pain grouped according to the CSI score and PPT value. METHOD: A total of 187 participants with chronic musculoskeletal pain were recruited. PPT, brief pain inventory, widespread pain index, pain catastrophizing scale, EuroQol-5 dimension, and CSI were assessed. Multiple regression analyses were performed using pain intensity and interference scores as dependent variables and the CSI score and PPT value as independent variables. Hierarchical cluster analysis was also performed to classify the participants into subgroups according to the CSI score and PPT value. Following the classification, pain-related characteristics and health-related QOL were compared among the subgroups. RESULTS: Multiple regression analyses demonstrated that only the CSI score significantly affected pain intensity and interference. As a result of the cluster analysis, three groups were identified: cluster 1 (n = 61, CSI low/PPT low group), cluster 2 (n = 78, CSI low/PPT high group), and cluster 3 (n = 48, CSI high/PPT low group). The CSI high/PPT low group had a higher incidence of pain-related symptoms than the CSI low group regardless of the PPT value. CONCLUSIONS: Combined CSI and PPT may not fully allow a detailed classification of pain-related characteristics. The CSI may be clinically more useful for assessing the effect of CS on pain-related symptoms.

Cutoff Value for Short Form of Central Sensitization Inventory.

OBJECTIVES: This study aimed to determine the optimal cutoff score of the 9-item short version of the CSI, the CSI-9, by comparing patients with central sensitivity syndrome (CSS) not only to healthy volunteers as with the original version, but also to patients with musculoskeletal (MSK) disorders. METHODS: All participants filled out the CSI, EuroQol 5-dimension, Brief Pain Inventory, and Pain Catastrophizing Scale questionnaires. To identify a clinically relevant cutoff score, receiver operating characteristic analyses were conducted. The area under the curve was used to examine the ability of the CSI-9 to distinguish patients with fibromyalgia (FM) from patients with MSK disorders and healthy individuals. RESULTS: Twenty-six participants with FM, 30 patients with MSK disorders, and 28 healthy individuals were included. We determined 2 cutoff scores: 20 for distinguishing patients with FM from patients with MSK disorders and 17 for distinguishing patients with FM from healthy individuals. These cutoff scores had good sensitivity (patients with MSK disorders, 92.3%; healthy individuals, 96.2%) and specificity (patients with MSK disorders, 93.3%; healthy individuals, 100%). In addition, the patients who scored above the cutoff of 20 points exhibited worse clinical symptoms (higher pain intensity, higher pain interference, higher Pain Catastrophizing Scale scores, and lower EuroQol 5-dimension scores) than those who scored below it. Furthermore, a significantly higher number of subjects who scored more than 20 on the CSI-9 had a history of 2 or more diagnoses of CSS. CONCLUSION: The optimal CSI-9 cutoff score of 20 is beneficial to clinicians in the evaluation of central sensitization-related symptoms. The cutoff score helps to identify patients who need additional treatments, such as pain neuroscience education and cognitive behavioral therapy.

Difference in the impact of central sensitization on pain-related symptoms between patients with chronic low back pain and knee osteoarthritis.

Purpose: The aims of the present study were to investigate whether the association between the Central Sensitization Inventory (CSI) score, pain-related symptoms, pain-related disability, and health-related quality of life differed by disease (chronic low back pain [CLBP] vs knee osteoarthritis [KOA]), and to determine optimal cutoff scores for the CSI reflecting disease-specific characteristics. Patients and methods: A total of 104 patients with CLBP and 50 patients with KOA were recruited. Central sensitization-related symptoms (CSI), EuroQol 5-dimension (EQ-5D), Brief Pain Inventory, widespread pain (Widespread Pain Index [WPI]), pressure pain threshold (PPT), and temporal summation (TS) were assessed and compared between the CLBP and KOA groups. Univariate correlation analysis was performed in each group. The receiver operating characteristic (ROC) curve analysis was performed to identify 1) presence/absence of central sensitization (CS), 2) presence/absence of central sensitivity syndromes (CSSs), and 3) pain intensity and pain interference in each group. Results: The CSI and WPI scores were significantly higher in the CLBP group than in the KOA group. EQ-5D and pain interference scores significantly correlated with the CSI score in both the CLBP and KOA groups. The WPI score, PPT, and TS did not correlate with the CSI score in either the CLBP or KOA group. The suggested cutoff scores were 28 in the CLBP group and 17 in the KOA group to identify presence or absence of CSSs, and 34 in the CLBP group and 18-19 in the KOA group to identify pain severity. Conclusion: The impact of CS on pain could differ between CLBP and KOA and that cutoff scores differ by each parameter we attempted to identify. Therefore, we should use the appropriate cutoff scores for the purposes and consider the difference in the impact of CS on pain by the patient group.

Validation of the Japanese version of the life satisfaction checklist (LiSat-11) in patients with low back pain: A cross-sectional study.

BACKGROUND: Previous studies suggest that life satisfaction assessment using the Life Satisfaction checklist (LiSat-11) is a meaningful outcome measure and may play an important role in setting rehabilitation goals in patients with chronic pain. Until now, there was no Japanese version of this questionnaire, and the psychometric properties of the original version of the LiSat-11 have only been investigated using classical test theory approaches. The objective of the present study was to evaluate the psychometric properties of the LiSat-11-J using Rasch analysis in a sample of Japanese people with low back pain (LBP). METHODS: One hundred and two participants with LBP completed the LiSat-11-J. Concurrent Validity of the LiSat-11-J was investigated by examining the relationships between the LiSat-11-J and clinical valuable. Rasch analysis was used to assess targeting, category ordering, unidimensionality, person fit, internal consistency, and differential item functioning. RESULTS: The LiSat-11-J was significantly correlated with disability, pain-related catastrophizing, fear of movement, anxiety, and depression. The LiSat-11-J targeted the participants with low life satisfaction and had unidimensionality, good internal consistency, and good test-retest reliability. Responses to category 1 ("very dissatisfying") and 2 ("dissatisfying") were disordered. After collapsing these two categories into a single new category, targeting function and category order showed a little improvement. CONCLUSION: The LiSat-11-J has unidimensionality, acceptable internal consistency, good test-retest reliability, and concurrent validity to the assessment of pain-related disability and psychological factors. However, targeting function and category order were not well. These two components showed improvement by rescoring category, but not sufficient. These results suggest that the LiSat-11-J is not well adequate to apply as an assessment tool of life satisfaction to the patients with LBP.

Development and psychometric properties of short form of central sensitization inventory in participants with musculoskeletal pain: A cross-sectional study.

BACKGROUND: The central sensitization inventory (CSI) comprises 25 items and is commonly used to measure somatic and emotional symptoms related to central sensitization symptoms. CSI was developed as an easy-to-administer screening instrument for patients at high risk of developing central sensitization in whom it was essential to quickly evaluate the condition. The purpose of the present study was to develop a short form of CSI and evaluate its psychometric properties using a contemporary approach called Rasch analysis. METHODS: A total of 505 patients with musculoskeletal disorders were recruited in this study. The CSI, pain intensity, pain interference, and the health-related quality of life (QOL) were evaluated for each participant. The original CSI items were consecutively analyzed using the Rasch model. Successive Rasch analyses were performed until a final set of items satisfied the model fit requirements. We also analyzed the psychometric properties of the original and short forms of CSI. RESULTS: Four consecutive Rasch analyses identified the removable items. Finally, the shortest questionnaire obtained that maintained the correct psychometric properties based on the Rasch model contained only 9 items (CSI-9). Rasch analysis showed that the CSI-9 had acceptable internal consistency, exhibited unidimensionality, had no notable differential item functioning, and was functional on the category rating scale. CONCLUSIONS: The nine-item short form of CSI has acceptable psychometric properties and is suitable for use for patients with musculoskeletal pain. Thus, the CSI-9 can be used as a brief instrument to evaluate central sensitization.

Validation of the Japanese version of the Central Sensitization Inventory in patients with musculoskeletal disorders.

BACKGROUND: Many musculoskeletal pain conditions are characterized by hypersensitivity, which is induced by central sensitization (CS). A questionnaire, the Central Sensitization Inventory (CSI), was recently developed to help clinicians identify patients whose presenting symptoms may be related to central sensitivity syndrome (CSS). The aims of the present study were to examine criterion validity and construct validity of the Japanese version of the CSI (CSI-J), and to investigate prevalence rates of CS severity levels in patients with musculoskeletal disorders. METHODS: Translation of the CSI into Japanese was conducted using a forward-backward method. Two hundred and ninety patients with musculoskeletal pain disorders completed the resultant CSI-J. A subset of the patients (n = 158) completed the CSI-J again one week later. The relationships between CSI and clinical symptoms, EuroQol 5-dimension (EQ-5D) and Brief Pain Inventory (BPI), were examined for criterion validity. EQ-5D assesses Health-related QOL and BPI measures pain intensity and pain interference. The psychometric properties were evaluated with analyses of construct validity, factor structure and internal consistency, and subsequently investigate the prevalence rates of CS severity levels. RESULTS: The CSI-J demonstrated high internal consistency (Cronbach's α = 0.89) and test-retest reliability was excellent value (ICC = 0.85). The CSI-J was significantly correlated with EQ-5D (r = -0.44), pain intensity (r = 0.42), and pain interference (r = 0.48) (p < 0.01 for all). Ten percent of the participants were above the cutoff "40". The exploratory factor analysis resulted in 5-factor model. CONCLUSIONS: This study reported that the CSI-J was a useful and psychometrically sound tool to assess CSS in Japanese patients with musculoskeletal disorders. The finding of the prevalence rates of CS severity levels in patients with musculoskeletal disorders may help clinicians to decide strategy of treatment.