The Fear-Avoidance Components Scale (FACS): Responsiveness to Functional Restoration Treatment in a Chronic Musculoskeletal Pain Disorder (CMPD) Population

Cultural Adaptation and Psychometric Validation of the Simplified Chinese Version of the Fear Avoidance Component Scale (FACS)

Background: Strong associations have been demonstrated between chronic musculoskeletal pain, pain-related fear-avoidance (FA) of activities of daily living, and functional disability. The Fear Avoidance Components Scale (FACS) is a patient-reported outcome (PRO) measure, which was designed to evaluate cognitive, emotional, and behavioural dimensions of FA. Objective: The study aims were to translate the English version of the FACS into Simplified Chinese and then to examine its psychometric properties. Methods: The translation and cross-cultural adaptation of the FACS from English to Chinese was performed with standard methodology. A group of 330 subjects with chronic musculoskeletal pain completed the FACS-Chi and additional FA-related PRO measures. The FACS-Chi was then completed a second time, 1 week later. Results: The FACS-Chi showed excellent internal consistency (Cronbach's alpha = 0.920) and test-retest reliability (ICC = 0.918). A confirmatory factor analysis of the 2-factor model determined in the original English version of FACS revealed an acceptable fit. Strong correlations were found between FACS-Chi scores and other PRO measures of perceived level of disability, pain catastrophizing, and pain-related anxiety (p < 0.001 for all analyses). Conclusions: The FACS-Chi demonstrated good psychometric properties, including excellent test-retest reliability and internal consistency and satisfactory construct validity. The FACS-Chi may be a useful measure of pain-related FA in Chinese-speaking patients with chronic musculoskeletal pain.

Measurement Properties of Two Questionnaires Assessing Fear-Avoidance in Patients With Chronic Low Back Pain

The Fear-Avoidance Components Scale (FACS) and the Fear of Daily Activities Questionnaire (FDAQ) assess fear-avoidance model components. However, the questionnaires are not available in Brazilian Portuguese. This study aimed to translate the original English FACS and FDAQ into Brazilian (Br) Portuguese and assess their measurement properties in patients with Chronic Low Back Pain (CLBP). One hundred thirty volunteers with CLBP participated in this study. Structural validity, internal consistency, test-retest reliability, and hypothesis testing for construct validity were analyzed. Results indicated a 2-factor solution for the FACS-Br, while the FDAQ-Br had a one-factor solution. Internal consistency showed acceptable Cronbach's alpha (alpha >.8). Suitable reliability was found for the FDAQ-Br (Intraclass Correlation Coefficient [ICC] = .98). For both FACS-Br factors, suitable reliability was found as well (ICC = .95 and .94). Hypothesis testing for construct validity confirmed more than 75% of the hypotheses proposed a priori for the FACS maladaptive pain/movement-related beliefs domain and the FDAQ-Br. In conclusion, the FACS-Br and FDAQ-Br demonstrated acceptable reliability, internal consistency, and structural validity measurement properties and their correlation (r < .50) suggests that the tools are not interchangeable measures.

Acceptance and Fear-Avoidance Mediate Outcomes of Interdisciplinary Pain Rehabilitation Programs at 12-Month Follow-Up: A Clinical Registry-Based Longitudinal Cohort Study from the Swedish Quality Registry for Pain Rehabilitation (SQRP)

Background

Factors that influence outcomes of interdisciplinary pain rehabilitation programs (IPRP) are poorly known. It is unclear how outcomes are influenced by pain intensity, psychological distress, and coping strategies.

Aim

This clinical registry-based longitudinal cohort study has three aims: 1) to determine the relative importance of pain intensity, psychological distress, acceptance, and fear-avoidance for changes in three outcomes of IPRP at 12-month follow-up; 2) to investigate whether the effects of pain intensity and psychological distress on the three outcomes are mediated via acceptance and fear-avoidance; and 3) to determine whether sex is a moderator.

Methods

This study uses Patient-Reported Outcome Measures (PROMs) from specialist units reporting data (2008-2016) to the Swedish Quality Registry for Pain Rehabilitation (SQRP). Adult chronic pain patients (N = 1991) answered the PROMs (background, pain, psychological distress, coping, participation, and health-related quality of life (HRQoL)). Partial Least Squares Structural Equation Modelling (PLS-SEM) was used to explore the aims.

Results

Changes in acceptance (β:0.424-0.553; all P<0.001) were the strongest predictor of the three outcomes (changes in life control, interference, and HRQoL) at 12-month follow-up. The next strongest predictor was baseline acceptance (β: 0.177-0.233; all P<0.001) and changes in fear-avoidance (β: -0.152- -0.186; all P<0.001). Baseline pain intensity and psychological distress showed weak positive associations. Their effects on the three outcomes were mediated via acceptance aspects. Sex was not a moderator.

Discussion and Conclusion

Acceptance aspects (baseline and changes) were important predictors of IPRP outcomes. Changes in fear-avoidance were also important although to a lesser degree. Some of the effects of pain intensity and psychological distress on outcomes were mediated via acceptance at baseline. Future PLS-SEM analysis of real-world IPRP should include more potential mediators (eg, catastrophizing and more facets of psychological flexibility and fear-avoidance) and the components of IPRP.

Catastrophizing and acceptance are mediators between insomnia and pain intensity-an SQRP study of more than 6,400 patients with non-malignant chronic pain conditions

Background

Sleep problems (insomnia) and chronic pain are associated. Chronic pain and insomnia/insufficient sleep quality share similar symptoms and features. Although they have a bidirectional relationship, more research is needed to understand how they interact via mediators and how moderators influence this relationship.

Aims

In this large clinical registry-based cohort study (N = 6,497), we investigate important mediators between insomnia and pain intensity in a cross-sectional sample of chronic pain patients using advanced path analysis. In addition, we investigate whether some background variables were moderators of the identified important paths or not and the correlation patterns between insomnia and pain intensity in relation to the mediators.

Methods

This study includes a cohort of adult patients with chronic non-cancer pain from the Swedish Quality Registry for Pain Rehabilitation (SQRP) with data on patient-reported outcome measures (PROMs) (2008-2016). The PROMs cover the background, pain aspects, psychological distress, pain-related cognitions, activity/participation, and health-related quality of life variables of the patients. Partial least squares structural equation modeling was used to explore the direct and indirect (via mediators) relationships between insomnia and pain intensity at baseline.

Results

In this cohort study, insomnia was prevalent at 62.3%, and both direct and indirect mediating paths were present for the insomnia-pain intensity relationship. All of the mediating effects combined were weaker than the direct effect between insomnia and pain intensity. The mediating effects via catastrophizing and acceptance showed the strongest and equal mediating paths, and mediating effects via fear avoidance were the second strongest. Insomnia showed stronger direct significant correlations with psychological distress, catastrophizing, and acceptance compared with those of pain intensity. Sex, age, education level, spatial extent of pain, or body mass index did not moderate the mediating paths.

Discussion and conclusion

This study confirms the existence of significant direct and mediating paths between reported insomnia and pain intensity. Future studies should focus on illuminating how sleep interventions influence pain intensity and other important key factors that contribute to the distress of chronic pain patients.

Patients with neuropathic pain from lumbosacral radiculopathy demonstrate similar pressure pain thresholds and conditioned pain modulation to those with fibromyalgia

OBJECTIVE

The purpose of the study was to evaluate pain thresholds, impairment of the endogenous pain modulatory system, and self-reported cognitive-emotional and central sensitization-related symptoms among three subject groups: a rarely studied patient cohort with neuropathic pain from lumbosacral radiculopathy (NPLSR), patients with fibromyalgia (FM) and healthy controls (HC).

METHODS

Patient-reported pain-related symptomology was evaluated with psychometricallyvalidated questionnaires. Pressure pain threshold (PPT), heat pain threshold (HPT), and cold pain threshold (CPT) were assessed in the low back and contralateral forearm. Conditioned pain modulation (CPM) was evaluated with a recently introduced methodology that accounts for a standard error of measurement.

RESULTS

Compared to the HC subjects, the FM and NPLSR subjects had significantly lower pain thresholds and more CPM impairment. No significant differences in PPT and CPM were observed between the FM and NPLSR groups. Significant group differences were found in self-reported symptoms of depression, anxiety, stress, and central sensitization. Self-reported symptom severity increased in a stair-step fashion, with the HC group scoring lowest and FM group scoring highest.

CONCLUSION

The NPLSR group manifested CPM dysfunction and pressure hyperalgesia at similar levels to the FM group, indicating that these two chronic pain syndromes, likely based on different pathophysiological mechanisms, in fact share some common pain processing features. However, though both patient groups demonstrated similarities in pain processing, self-reported cognitive-emotional and central sensitization-related symptom severity was significantly higher in the FM cohort, which distinguished them from the chronic NPLSR cohort.

The development and measurement properties of the Dutch version of the fear-avoidance components scale (FACS-D) in persons with chronic musculoskeletal pain

OBJECTIVES

The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument assessing different constructs related to the fear-avoidance model of pain. The aim was to translate the original English FACS into Dutch (FACS-D) and assess its measurement properties in persons with chronic musculoskeletal pain.

METHODS

The original English FACS (20 item-scale, range: 0-100) was translated in Dutch through standard forward-backward translation methodology. The FACS-D's measurement properties were evaluated in 224 persons with chronic musculoskeletal pain. Internal consistency, test-retest reliability and measurement error were assessed with the Cronbach's alpha coefficient (α), intraclass correlation coefficient (ICC), and standard error of measurement (SEM). Construct validity was assessed through inter-item correlation analyses, exploratory factor analysis, association with other fear-avoidance-related constructs, and hypothesis testing.

RESULTS

Internal consistency, test-retest reliability and hypotheses testing were good (α=0.92; ICC=0.92, CI 0.80-0.96; 7/8 hypotheses confirmed). Similar to the original FACS and other translated versions, a two-factor model best fit the data. However, the item distribution differed from other versions. One factor represented "pain-related cognitions and emotions" and a second factor represented "avoidance behaviour." In contrast to the original FACS, low inter-item correlations for item 12 were found. The FACS-D was more strongly associated with fear-avoidance-related constructs of pain severity, perceived disability, feelings of injustice, and depressive/anxiety symptoms than the other fear-avoidance-related scales studied here.

CONCLUSIONS

The FACS-D demonstrated good reliability and construct validity, suggesting that it may be a useful measure for Dutch-speaking healthcare providers. Two clinically relevant factors, with a different item distribution than the original FACS, were identified: one covering items on pain-related cognitions and emotions, and one covering items on avoidance behaviour. The stronger association between FACS-D and fear-avoidance related constructs suggests that the FACS-D may be more effective in evaluating the cognitive, emotional and behavioural constructs of pain-related fear-avoidance than other similar measures.

Development and validation of a military fear avoidance questionnaire

Chronic pain due to musculoskeletal injury is one of the leading causes of disability and reduced combat readiness in the U.S. Army. Unidimensional pain management systems are not effective in addressing the complex phenomenon of pain-related disability. Growing evidence has supported use of the Fear Avoidance Model (FAM) as a suitable model to address pain-related disability and chronicity from a multidimensional pain neuroscience approach. While several fear avoidance measurement tools exist, one that addresses the complexity of the Army environment encouraged the authors to develop and test the reliability and validity of a military specific questionnaire. This study developed and validated an Army specific fear avoidance screening, the Return to Duty Readiness Questionnaire (RDRQ), which subsequently demonstrated good psychometric properties. Reliability coefficients demonstrate high internal consistency values both during pilot study (α = 0.96) and validation study (α = 0.94, ωt = 0.94). A Correlation Coefficient of 0.74 when compared with the Fear Avoidance Components Scale (FACS) suggests good concurrent validity. Future study should include replication in a new army population, investigation of responsiveness, test-retest reliability, structural validity and establishing severity scores with minimal clinically important differences to enhance utility.

Health screening questionnaires used in the management of mental distress acquired during an injured worker’s return to work: A scoping review

BACKGROUND: Mental distress is often endured by injured workers participating in the rehabilitation or return to work process following a physical injury. Delays in detecting the onset and treating mental distress can lead to a diverse range of cognitive and behavioural changes that may precipitate psychological distress such as anxiety, depression, and posttraumatic stress. OBJECTIVE: The objective of this scoping review was to provide an overview of existing health questionnaires utilised by health care providers and affiliated researchers. It reviewed their effectiveness and suitability to detect mental distress endured by injured workers engaged in the return to work process. METHODS: A scoping review methodology was conducted using the Arksey and O’Malley framework which examined peer-reviewed articles published between 2000 and March 2020 comprising health questionnaires. Database searches included Medline, CINAHL, EMBASE and PsycINFO combining specific MeSH terms and key words. RESULTS: The full search identified 3168 articles. Following full screening a total of 164 articles reviewed the use of health questionnaires and specific criteria to determine their suitability. Most of the health questionnaires reviewed were used as screening measures for identifying both work and non-work-related psychological hazards. However, they were found to be limited in their application when considering all potential predictors of delayed return to work such as poor or stressful interactions with stakeholders, financial stress and the injured workers experience of the RTW process. CONCLUSION: Earlier identification of mental distress using an optimal MHSQ followed by appropriate intervention will reduce the risk of psychological injury becoming cumulative on a physical workplace injury. Without such complications, early return to work can be achieved with significant cost saving to the economy.

Psychological risk factors for the occurrence of frozen shoulder after rotator cuff repair

INTRODUCTION

Frozen shoulder is a dreaded complication after rotator cuff repair.

HYPOTHESIS

There are psychological determinants for this complication.

MATERIALS AND METHODS

We prospectively included 77 consecutive patients who underwent arthroscopic rotator cuff repair between May 2018 and April 2019. Along with a functional evaluation, we determined the Constant score, anxiety and depression levels based on the HADS, and kinesiophobia based on the Tampa Scale preoperatively and 6months after the surgery.

RESULTS

At the 6-month follow-up, 8 patients had been diagnosed with frozen shoulder (group A), 65 patients had satisfactory joint range of motion (group B) and 4 were lost to follow-up. In the frozen shoulder group, the preoperative anxiety rate was significantly higher than in group B (50% versus 17%, p=0.04). Furthermore, there were significantly more women (p=0.028) and more patients with an occupational disease in group A (75% versus 18%, p=0.027). At 6months postoperative, the Constant score was 55 in the group with a frozen shoulder versus 72 in group B (p=0.004). Neither depression nor kinesiophobia were risk factors for the development of frozen shoulder after rotator cuff repair.

CONCLUSION

Preoperative anxiety, the female sex and occupational disease are all risk factors for the occurrence of frozen shoulder after rotator cuff repair. Knowing these predisposing factors will help us better manage at-risk patients.

LEVEL OF EVIDENCE

III, prospective study.

The Benefits of a Therapeutic Exercise and Educational Intervention Program on Central Sensitization Symptoms and Pain-Related Fear Avoidance in Breast Cancer Survivors

BACKGROUND

Central sensitization symptoms and pain-related fear avoidance are two common problems in breast cancer survivors. Non-pharmacologic interventions such as therapeutic exercise and patient education can be effective in this population.

AIMS

This study aimed to: (1) analyze the benefits of a therapeutic exercise and educational program on central sensitization symptoms and pain-related fear avoidance in breast cancer survivors, and (2) explore the association between pain-related fear avoidance and central sensitization symptoms.

DESIGN

A single group pre-post intervention study was conducted.

METHODS

Patients were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). The intervention consisted of a therapeutic exercise and educational program that lasted 12 weeks, twice a week, for 1 hour. Two instruments were used: the Spanish version of the Central Sensitization Inventory and the Spanish Fear Avoidance Components Scale.

RESULTS

A total of 82 breast cancer survivors participated in the study. Pre-post change on Central Sensitization Inventory was statistically significant (p = .007). There was a trend towards a significant difference for the Spanish Fear Avoidance Components Scale (p = .062). There was a statistically significant correlation between pain-related fear avoidance and central sensitization symptoms (r = 0.536, p < .001).

CONCLUSIONS

The current study has provided preliminary evidence on the benefits of this intervention in pain-related fear avoidance and central sensitization symptoms in breast cancer survivors. The Spanish version of the Central Sensitization Inventory and the Spanish Fear Avoidance Components Scale demonstrated responsiveness to change.

Validity and reliability of the Spanish fear-avoidance components scale in breast cancer survivors

OBJECTIVE

The aim of this study was to carry out a psychometric analysis of the Fear-Avoidance Components Scale (FACS-Sp) in Spanish breast cancer survivors (BCS).

METHODS

A validation study was carried out in 154 BCS. Participants were recruited from the service of Medical Oncology of the University Clinical Hospital Virgen de la Victoria, in Málaga (Spain). A psychometric analysis of internal consistency, internal structure and convergent validity of the FACS-Sp was performed. Cronbach's alpha was calculated for internal consistency. Exploratory Factor Analysis was used to determine the internal structure of the FACS-Sp. Convergent validity with the Tampa Scale of Kinesiophobia (TSK) and the Pain Catastrophizing Scale (PCS) was determined using the Pearson correlation coefficient.

RESULTS

The internal consistency was high (McDonald's ω = 0.91). The Exploratory Factor Analysis yielded one factor explaining the 40.80% of total variance. Convergent validity with the TSK and the PCS was demonstrated.

CONCLUSIONS

The FACS-Sp has demonstrated to be a valid and reliable measure for assessing pain-related fear avoidance in BCS based on internal consistency, structural validity and convergent validity. Further studies that analyse other measurement properties in different Spanish cancer populations are needed.

Convergent and Discriminant Validity of the Serbian Version of the Central Sensitization Inventory

OBJECTIVES

The goal of the present study was to explore additional evidence of validity of the Serbian version of the Central Sensitization Inventory (CSI), a patient-reported outcome measure of symptoms that have been found to be associated with central sensitization (CS). The CSI has been found to be psychometrically sound, and has demonstrated evidence of convergent and discriminant validity in numerous published studies and in multiple languages.

METHODS

CSI data were collected from 399 patients with chronic pain who had various diagnoses and from 146 pain-free controls. In addition, the patient sample completed a battery of validated patient-reported outcome measures of sleep problems, cognitive problems, pain catastrophizing, pain-related fear-avoidance, decreased quality of life, and decreased perception of social support. Six patient subgroups were formed, with presumably different levels of CS (including those with fibromyalgia, multiple pain sites, and localized pain sites).

RESULTS

Significant differences were found in total CSI scores among the controls and patient subgroups. Those with fibromyalgia and multiple pathologies scored highest and the control subjects scored lowest. Other patient-reported CS-related symptom dimensions were significantly correlated with total CSI scores. When the patients were divided into CSI severity subgroups (from subclinical to extreme), the severity of these other symptom dimensions increased with the severity of CSI scores.

CONCLUSIONS

The current study successfully demonstrated additional evidence of the convergent and discriminant validity of the Serbian version of the CSI.

Pain Neuroscience Education and Physical Therapeutic Exercise for Patients with Chronic Spinal Pain in Spanish Physiotherapy Primary Care: A Pragmatic Randomized Controlled Trial

Chronic musculoskeletal pain affects more than 20% of the population, leading to high health care overload and huge spending. The prevalence is increasing and negatively affects both physical and mental health, being one of the leading causes of disability. The most common location is the spine. Most treatments used in the Public Health Services are passive (pharmacological and invasive) and do not comply with current clinical guidelines, which recommend treating pain in primary care (PC) with education and exercise as the first-line treatments. A randomized multicentre clinical trial has been carried out in 12 PC centres. The experimental group (EG) conducted a program of pain neuroscience education (6 sessions, 10 h) and group physical exercise with playful, dual-tasking, and socialization-promoting components (18 sessions in 6 weeks, 18 h), and the control group performed the usual physiotherapy care performed in PC. The experimental treatment improved quality of life (d = 1.8 in physical component summary), catastrophism (d = 1.7), kinesiophobia (d = 1.8), central sensitization (d = 1.4), disability (d = 1.4), pain intensity (d = 3.3), and pressure pain thresholds (d = 2). Differences between the groups (p < 0.001) were clinically relevant in favour of the EG. Improvements post-intervention (week 11) were maintained at six months. The experimental treatment generates high levels of satisfaction.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Psychometric validation of the Serbian version of the Fear Avoidance Component Scale (FACS)

OBJECTIVE

The Fear Avoidance Components Scale (FACS) is a new patient-reported outcome (PRO) questionnaire designed to comprehensively evaluate fear avoidance (FA) beliefs and attitudes in persons with painful medical conditions. The original English version has demonstrated acceptable psychometric properties, including concurrent and predictive validity. Two factors have been identified: 1. general fear avoidance; and 2. types of activities that are avoided.

METHODS

The FACS was first translated into Serbian, and then psychometrically validated. A cohort of 322 chronic musculoskeletal pain subjects completed the FACS-Serb and additional FA-related patient-reported outcome (PRO) measures. Their FACS-Serb scores were then compared to a cohort of 68 acute pain subjects.

RESULTS

Test-retest reliability (ICC2,1 = 0.928) and internal consistency for both Factors (Cronbach α 0.904 and 0,880 respectively) were very good. An acceptable fit was found with a confirmatory factor analysis of the 2-factor model found with the original English version of the FACS. Strong associations were found among FACS-Serb scores and other PRO measures of pain catastrophizing, depressive/anxiety symptoms, perceived disability, and pain intensity (p<0.001 for all analyses). FACS-Serb total scores, separate Factor scores, and subjective pain ratings were significantly higher in the chronic vs. acute pain cohorts (p<0.001 for all analyses).

CONCLUSIONS

The FACS-Serb demonstrated strong psychometric properties, including strong reliability and internal consistency, criterion validity (through associations with other FA-related PRO measures), and discriminant validity (through comparisons with a separate acute pain cohort). The FACS-Serb appears to be a potentially useful pain-related assessment tool.