Psychometric Properties of the PCS and the PCS-4 in Individuals With Musculoskeletal Pain.

BACKGROUND: The factor structure of the Pain Catastrophizing Scale (PCS) has rarely been adequately analyzed (e.g., performing principal component analyses rather than factorial approximations). We aimed to evaluate the psychometric properties of the PCS through a variety of exploratory and confirmatory factorial approaches. METHOD: Three hundred ninety-four Chilean patients with musculoskeletal pain were included (age, M = 49.61, SD = 18.00; 71.57% women). Eight factorial models were proposed to analyze the structure of the data. In addition, validity evidence of the PCS based on relationships with other variables were analyzed considering pain intensity and kinesiophobia. RESULTS: The results suggest a unidimensional structure. Models with more than one dimension exhibited undesirable factor loadings or inadequate indices of fit. Based on these results, a short version of the scale composed of 4 items is proposed (PCS-4). The PCS-4 scores demonstrated high levels of invariance between sex, chronicity, and education groups and also were associated with pain and kinesiophobia. CONCLUSIONS: The results of the PCS-4 Spanish version showed evidence of reliability and validity for adequately measuring pain catastrophizing in Chileans who suffer from musculoskeletal pain. The PCS-4 is a short form that should be explored in future studies (e.g., in other Spanish-speaking populations).

Psychometric Properties of the PCS and the PCS-4 in Individuals With Musculoskeletal Pain / Propiedades Psicométricas de la PCS y PCS-4 en Individuos con DolorMusculoesquelético

Background: The factor structure of the Pain Catastrophizing Scale (PCS)has rarely been adequately analyzed (e.g., performing principal componentanalyses rather than factorial approximations). We aimed to evaluate thepsychometric properties of the PCS through a variety of exploratory andconfirmatory factorial approaches. Method: Three hundred ninety-fourChilean patients with musculoskeletal pain were included (age, M = 49.61,SD = 18.00; 71.57% women). Eight factorial models were proposed toanalyze the structure of the data. In addition, validity evidence of the PCSbased on relationships with other variables were analyzed considering painintensity and kinesiophobia. Results: The results suggest a unidimensionalstructure. Models with more than one dimension exhibited undesirablefactor loadings or inadequate indices of fit. Based on these results, a shortversion of the scale composed of 4 items is proposed (PCS-4). The PCS-4scores demonstrated high levels of invariance between sex, chronicity, andeducation groups and also were associated with pain and kinesiophobia.Conclusions: The results of the PCS-4 Spanish version showed evidenceof reliability and validity for adequately measuring pain catastrophizing inChileans who suffer from musculoskeletal pain. The PCS-4 is a short formthat should be explored in future studies (e.g., in other Spanish-speakingpopulations).

Antecedentes: la estructura factorial de la Escala deCatastrofización del Dolor (PCS) rara vez se ha analizado adecuadamente. Elobjetivo de este estudio fue evaluar las propiedades psicométricas del PCSa través de diferentes enfoques factoriales exploratorios y confirmatorios.Método: se incluyeron trescientos noventa y cuatro pacientes chilenos condolor musculoesquelético (edad, M=49,61; DE=18,00; 71,57% mujeres). Sepropusieron ocho modelos factoriales. Asimismo, se analizó la evidencia devalidez de la PCS basada en relaciones con otras variables considerando laintensidad del dolor y la kinesiofobia. Resultados: los resultados sugierenuna estructura unidimensional. Los modelos con más de una dimensiónmostraron cargas factoriales o índices de ajuste inadecuados. A partir deestos resultados se propone una versión corta de la escala compuesta por4 ítems (PCS-4). Las puntuaciones de PCS-4 mostraron altos niveles deinvarianza entre sexos, cronicidad del dolor y niveles educativos. La PCS-4también se asoció con otras medias de dolor y kinesiofobia. Conclusiones:los resultados de la PCS-4 versión en español mostraron evidencia defiabilidad y validez para medir adecuadamente el catastrofismo del dolor enchilenos con dolor musculoesquelético. El PCS-4 es una forma corta quedebería explorarse en estudios futuros (por ejemplo, en otras poblacioneshispanoparlantes).

The Effect of Sleep Quality on Pain in Chilean Individuals with Musculoskeletal Disorders.

Poor sleep quality (SQ) negatively affects pain associated with musculoskeletal disorders (MSD). As the level of economic development of a country determines its sanitary conditions, these can influence the sleep-pain relationship; therefore, it is relevant to generate evidence in the population with MSD in developing countries. This cross-sectional study sought to determine the effect of poor SQ on pain in Chilean individuals with MSD, controlling for sex and duration of pain (in months). METHOD: A total of 228 individuals were included. SQ was measured with the Pittsburg Sleep Quality Index (PSQI), pain (intensity, interference and distress relative to pain) was measured with visual analog scales. Structural equation modeling (SEM) was performed to analyze the effect of SQ on pain. RESULTS: A high frequency of poor SQ was present in the studied group, and was more prevalent in women. The SEM model evidenced that poor SQ predicts greater pain. Sex influences sleep quality and pain, but not pain duration. CONCLUSIONS: These findings indicate that poor SQ predicts higher pain in MSD and that women exhibit worse SQ and more significant pain than men. Our findings support that SQ should be considered in the comprehensive approach to pain in individuals with MSD.