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

Abstract

BackgroundThe 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.MethodsA 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.ResultsFour 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.ConclusionsThe 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.

Cutoff Value for Short Form of Central Sensitization Inventory

“…In the present study, the optimal cutoff points were selected using the ROC curve closest to the upper left corner of the unit square, which also optimized the prevalence-independent summary measures of sensitivity and specificity, according to the Youden Index. 35 In the previous study, 3 CSI-9 severity levels were determined-subclinical (0 to 9), mild (10 to 19), and moderate/severe (20 to 36) 15 -and the cutoff score of 20 indicated a boundary between mild and moderate/severe levels of severity. It was consistent with the original version of the CSI: 5 levels of severity were suggested-subclinical (0 to 29), mild (30 to 39), moderate (40 to 49), severe (50 to 59), and extreme (60+) 16 -and the cutoff score of 40 indicated a boundary between mild and moderate levels of severity.…”

“…The CSI‐9 answers were extracted from the full CSI. The CSI‐9 was developed using Rasch analysis and had good internal consistency (Cronbach's alpha = 0.80) and test‐retest reliability (intraclass correlation coefficient [ICC] 3,1 = 0.79) . Both CSIs consist of 2 parts: A and B.…”

“…The CSI-9 was developed using Rasch analysis and had good internal consistency (Cronbach's alpha = 0.80) and test-retest reliability (intraclass correlation coefficient [ICC] 3,1 = 0.79). 15 Both CSIs consist of 2 parts: A and B. Part A of the original CSI and the CSI-9 consists of 25 and 9 items, respectively.…”

“…Therefore, a short version of the questionnaire was needed. The 9‐item short version of the CSI (CSI‐9) was developed and the psychometric properties confirmed, allowing clinicians to identify the presence of a CSS more rapidly and easily using the CSI‐9 rather than the original CSI . In the original article about the CSI, the 40‐point cutoff score and the severity levels were determined by comparing individuals with CSS to healthy volunteers .…”

“…The 9item short version of the CSI (CSI-9) was developed and the psychometric properties confirmed, allowing clinicians to identify the presence of a CSS more rapidly and easily using the CSI-9 rather than the original CSI. 15 In the original article about the CSI, the 40-point cutoff score and the severity levels were determined by comparing individuals with CSS to healthy volunteers. 1,16 Although the severity levels of the CSI-9 were determined by comparing the scores depending on the number of CSSs in patients with musculoskeletal (MSK) disorders, 15 the cutoff scores of the CSI-9 have still not been clarified.…”