|Year : 2020 | Volume
| Issue : 2 | Page : 98-107
Cross-cultural adaptation, reliability, and validity of the Gujarati fear-avoidance components scale
Dibyendunarayan Dhrubaprasad Bid1, Randy Neblett2, Thangamani Ramalingam Alagappan1, Charmy J Patel1, Karishma N Patel1, Rinkal L Patel1, Shama J Narola1, Vyoma V Sailor1
1 Department of Musculoskeletal, Physiotherapy, Sarvajanik College of Physiotherapy, Surat, Gujarat, India
2 Research Coordinator, PRIDE Research Foundation, Dallas, Texas, USA
|Date of Submission||29-Dec-2019|
|Date of Decision||17-Jun-2020|
|Date of Acceptance||25-Jun-2020|
|Date of Web Publication||31-Dec-2020|
Dr. Dibyendunarayan Dhrubaprasad Bid
Sarvajanik College of Physiotherapy, Rampura, Surat - 395 003, Gujarat
Source of Support: None, Conflict of Interest: None
BACKGROUND: The Fear-Avoidance Components Scale (FACS) is a relatively new patient-reported outcome measure to measure pain-related fear avoidance (FA).
OBJECTIVES: The aim of this study was to translate and culturally adapt the FACS into the Gujarati language and to determine the test–retest reliability and cross-cultural validity of the FACS-G in Gujarati-speaking Indian patients.
METHODS: Translation and cross-cultural adaptation of the original English version of the FACS were performed according to published guidelines. Test-item comprehension was verified in a group of 20 patients with chronic musculoskeletal pain disorders (CMPDs) with a written survey and cognitive debriefing interview. The content validity of the final version of the FACS-G was then ascertained from a survey of 30 health-care professionals. A cohort of 150 CMPD patients completed the FACS-G and other FA-related patient-reported outcome measures to determine internal consistency, test–retest reliability, agreement, minimal detectable change (MDC), and construct validity.
RESULTS: In the opinion of the health-care professional panel, the content validity was very good. The internal consistency (Cronbach's α = 0.827) and test–retest reliability (intraclass correlation coefficient = 0.923 [95% confidence interval = 0.837–0.963]) were both excellent. The MDC was found to be 13.27 points (scale range = 0–100). The FACS-G correlated most strongly with the FA Beliefs Questionnaire-G (r = 0.705), which supports the concept of convergent validity. It showed a weaker association with the depressive symptom subset of the Patient Health Questionnaire (r = 0.461), which supports the concept of divergent validity. It correlated moderately with the Roland-Morris Disability Questionnaire-G (r = 0.615) and Numerical Pain Rating Scale score (r = 0.521; P < 0.01).
CONCLUSION: The FACS-G showed strong psychometric properties, providing evidence of the conceptual equivalence with the original English version. The FACS-G appears to be a reliable instrument for measuring FA in Gujarati patients with CMPD.
Keywords: Chronic musculoskeletal pain disorders, fear avoidance, Fear-Avoidance Components Scale-Gujarati, reliability, validity
|How to cite this article:|
Bid DD, Neblett R, Alagappan TR, Patel CJ, Patel KN, Patel RL, Narola SJ, Sailor VV. Cross-cultural adaptation, reliability, and validity of the Gujarati fear-avoidance components scale. Physiother - J Indian Assoc Physiother 2020;14:98-107
|How to cite this URL:|
Bid DD, Neblett R, Alagappan TR, Patel CJ, Patel KN, Patel RL, Narola SJ, Sailor VV. Cross-cultural adaptation, reliability, and validity of the Gujarati fear-avoidance components scale. Physiother - J Indian Assoc Physiother [serial online] 2020 [cited 2021 Jul 28];14:98-107. Available from: https://www.pjiap.org/text.asp?2020/14/2/98/305841
| Introduction|| |
To cope with a painful medical condition or injury, patients can use adaptive strategies, such as utilizing social support and confronting the situation, or adopt maladaptive strategies, such as fear-avoidance (FA) behaviors, when patients avoid physical and/or social activities of daily living because they are afraid of pain and/or re-injury. Although FA may be considered adaptive on a short term basis, as it may prevent further tissue damage or exacerbation of injury, chronic FA is associated with many negative consequences, such as altered cognitive processing of pain, increased depressive symptoms, catastrophizing, increased pain intensity, somatization, decreased physical activity, functional impairment, and disability from activities of daily living.,
Several different FA-related patient-reported measures exist, including the Pain Catastrophizing Scale (PCS),, the Tampa Scale for Kinesiophobia (TSK), the FA Beliefs Questionnaire (FABQ), and the Pain Anxiety Symptoms Scale (PASS), but they have been criticized for psychometric flaws.,, In addition, although each of these measures assesses specific components of FA, all of them were introduced before the well-accepted FA model of chronic pain was fully developed, so they do not provide a comprehensive evaluation of all important cognitive, behavioral, and emotional components of the model. There are no available cutoff scores for the PCS and FABQ to help with clinical interpretation, and it was only relatively recently that severity ranges were proposed for the PASS and TSK., A lack of cutoff scores or severity ranges makes self-report measures less desirable in clinical settings. In contrast, the FA Components Scale (FACS) provides a comprehensive measure of FA based on the well-established FA model of chronic pain, with solid psychometric properties, and five severity ranges (from subclinical to extreme) for clinical interpretation. In previous studies, the FACS has demonstrated strong reliability, internal consistency, and criterion and discriminant validity. Exploratory factor analyses in three separate studies have confirmed two factors, representing “general FA” (items 1–14) and “types of activities that are avoided”(items 15–20).,, When evaluating treatment responsiveness in a functional restoration treatment program, it has shown the ability to predict physical performance and relevant posttreatment work outcomes in patients with chronic musculoskeletal pain disorders (CMPDs).
The availability of non-English versions of the FACS questionnaire offers an additional clinical tool for evaluating FA in non-English-speaking CMPD populations. It can provide a standard measure for use in international studies and clinical practice and can allow clinicians and researchers to share information and clinical outcomes. Furthermore, it can allow direct comparisons across countries as well as simplifying the process of a meta-analysis of clinical studies. To date, the original English version of FACS has been successfully translated and validated in two non-English-speaking languages, including European-style Spanish (FACS-Sp) and Serbian (FACS-Serb). A Gujarati version of the FACS has not yet been available. The Gujarati language is used by over 50 million people, primarily in the Indian state of Gujarat. As with other large populations, chronic pain is a common problem for Gujarati-speaking people. A psychometrically validated Gujarati version of the FACS will provide Gujarati-speaking health-care providers with useful tool for evaluating FA.
The objectives of the present study were to translate and cross-culturally adapt the FACS into the Gujarati language and then determine the psychometric properties of the FACS-G in Gujarati-speaking Indian patients. To help assess construct validity, associations were determined between the FACS-G and other FA-related variables. We hypothesized that the FACS-G would correlate highly with the FABQ-G, as they both measure aspects of FA. We anticipated moderate-to-high correlations with subjective pain intensity ratings and perceived level of pain-related disability, which have previously been found to be associated with FA., We anticipated lower correlations with self-reported symptoms of depression, a related but different construct than FA.
| Methods|| |
This study was done in three phases. First, the original English version of the FACS was translated into the Gujarati language (resulting in the FACS-G), following standard guidelines., Second, a panel of experts evaluated the content validity of the FACS-G items. Third, the psychometric properties of the FACS-G were evaluated in a group of CMPD patients, including measures of test–retest reliability, internal consistency, and convergent and divergent validity.
A sample of 150 CMPD patients were recruited through a prospective convenience sampling. All patients had been referred for outpatient physiotherapy treatment at various clinics in Surat. A written consent was obtained from each of them. The protocol was approved by the Institutional Ethics Committee of Hajee A. M. Lockhat and Dr. A. M. Moolla Sarvajanik Hospital, Rampura, Surat, India, on May 7, 2017.
CMPD was defined as duration of musculoskeletal pain for >6 months. Patients were excluded if they had previous back, neck, shoulder, knee, or brain surgery within 6 months, whiplash injury, cardiovascular or respiratory problems, pregnancy, presence of any systemic disease, cognitive impairment, or communication difficulties. Patients were also excluded if their CMPD was due to other secondary causes such as cancer. The intention was to study patients with only common CMPDs without major traumatic background, either naturally or clinically, as it may influence the FA component. Data were collected from CMPD patients consecutively at their admission for treatment from November 2017 to March 2018.
Phase I: Cross-cultural adaptation process
A five-step guideline suggested by Beaton and Guillemin was followed [Figure 1]. Step 1: Forward translation (English to Gujarati): Two bilingual translators whose mother tongue was Gujarati, one aware of the concepts of the measure and one uninformed with no medical background, translated the FACS from English to Gujarati. This stage involved two forward translations: T1 and T2. Step 2: Synthesis: A synthesized version (T-12) was produced by combining both T1 and T2 after a conciliation meeting between the two translators and one of the authors (BDD). Step 3: Back translation (Gujarati to English): The synthesized version (T-12) was translated back into English by two independent qualified translators to identify inconsistencies in the words and concepts of the synthesized version. This was referred to as BT1 and BT2. The translators were unfamiliar with the original version of FACS. The back translation was checked and compared against the original FACS for possible disparities by a native English speaker and one of the authors (author RN). Step 4: Expert committee review: An expert committee made up of the investigators and all four translators met to discuss problems of cultural adaptations and linguistic equivalence with the original English version of the FACS. The outcome of this stage resulted in the prefinal version of the FACS-G. Step 5: Pretesting: Pilot testing of the target language version was done to check the layout, wording, and ease of understanding of the questionnaire. It was given to 20 Gujarati-speaking patients (12 females and 8 males with mean age 51 ± 14 years) with CMPD. On completion of the questionnaire, an individual interview was done to probe how each patient interpreted each questionnaire item and how responses were chosen (cognitive debriefing). Each respondent's understanding of items was probed to evaluate whether the adapted version retained equivalence to the items of the English version. This stage was important for evaluating comprehensibility of the content. Only one patient had difficulty answering one item (7: “It is unfair that I have to live with my painful medical condition”…….). Therefore, it was decided that no additional modifications of the items were necessary. The FACS-G can be found in [Appendix 1].
Phase II: Evaluation of content validity
Content validity was assessed by an expert panel of 30 health-care professionals comprising physicians, orthopedic surgeons, neurologists, psychiatrists, nurses, and physiotherapists who were fluent in both Gujarati and English languages. They each assessed the FACS-G and then completed a questionnaire about content equivalence to the English version and content relevance and representativeness of FA in CMPD patients.
Content equivalence was assessed under two headings: (1) Are the words in the translated Gujarati version presented fluently and correctly as in the original version? (2) Do the words and phrases in the translated Gujarati version have the same semantic meaning compared with the original version?
Content relevance was assessed by asking this question: Is the Gujarati statement relevant for assessing musculoskeletal pain and FA behavior in CMPD patients?
Content representativeness was assessed by asking “How well does the content (Item no. 1–20) of the FACS-G assess the entire domain of musculoskeletal pain and FA behavior in CMPD patients?”
Part III: Psychometric evaluation process
A sample of 150 CMPD patients (mentioned previously in the Subjects section) completed a demographic information form and a series of self-report measures, including the FACS. For the evaluation of test–retest reliability, a subsample of 30 patients completed the FACS, a second time approximately 48 h later, in an attempt to minimize possible changes in the clinical status.
Fear-Avoidance Components Scale
Each item is scored on a 6-point Likert scale, from 0 “completely disagree” to 5 “completely agree.” Total scores, which range from 0 to 100, indicate a clinical level: subclinical (0–20), mild (21–40), moderate (41–60), severe (61–80), and extreme (81–100).
Fear-Avoidance Beliefs Questionnaire Gujarati version
The FABQ was developed by Waddell et al. to measure FA beliefs in LBP patients. It is a 16-item, self-reporting questionnaire, in which each item is graded on a 7-point Likert scale from strongly disagree to strongly agree. The FABQ score is calculated by adding up individual item scores. A higher total score indicates a higher level of FA beliefs. The FABQ English version has demonstrated high levels of internal consistency (Cronbach's alpha = 0.88) and test–retest reliability (r = 0.95). The original FABQ has recently been translated and found to be reliable and valid for Gujarati-speaking patients with CLBP.
Roland-Morris Disability Questionnaire Gujarati version
The RMDQ is a disability measure in which greater levels of disability are reflected by a higher score on a 24-point YES/NO scale. Patients were asked to place a check mark beside each statement if it applies to them. Disability scores for each patient were determined by the total of items checked. Three score ranges, indicating disability severity, have been recommended for clinical interpretation: 0–8 for minimal disability, 9–16 for moderate disability, and 17–24 for significant disability. The RMDQ-G has been shown to have good internal and external validity, as well as adequate internal consistency.,
Numerical Pain Rating Scale
The intensity of musculoskeletal pain was assessed with an 11-point Numerical Pain Rating Scale (NPRS). Participants were asked the following question: “On a scale of 0–10, where 0 means no pain and 10 means the worst imaginable pain, select the single number that best represents your pain intensity.” The scale has been shown to have adequate reliability, validity, and responsiveness in patients with CLBP.
Patient Health Questionnaire-9 Gujarati
The PHQ-9  is a subset of the Pain Health Questionnaire that assesses depressive symptoms. Each of the 9 items is scored “0” (not at all) to “3” (nearly every day). PHQ-9 cutoff scores of 5, 10, 15, and 20 represented mild, moderate, moderately severe, and severe depression, respectively. A psychometric validation of the Gujarati version of PHQ-9 has not yet been published.
Reliability is a generic term used to indicate both the homogeneity (internal consistency) of a scale and the reproducibility (test–retest reliability) of scores. Internal consistency was calculated by the Cronbach's alpha, which was based on the average correlation of items within a test. Internal consistency is treated as acceptable when Cronbach's alpha exceeds 0.70. The intraclass correlation coefficient (ICC) was used for assessment of test–retest reliability between the FACS-G scores obtained at baseline and a second visit 48 h later.
The ICC values range from 0 to1: 1 = perfect reliability, 0.90–0.99 = very high correlation, 0.70–0.89 = high correlation, 0.50–0.69 = moderate correlation, 0.26–0.49 = low correlation, and 0.00–0.25 = little, if any, reliability.
The Bland–Altman plot is a measure of within-subject variation. It was used to assess the agreement between the FACS-G test and retest scores, by plotting the mean difference in the FACS-G scores for the two occasions against the baseline FACS-G scores. 95% confidence interval around the mean difference was calculated, and the limits of agreement were plotted.
The standard error of measurement (SEM) was used to determine the measurement error. The SEM is derived from the square root of the within-subject variance obtained from the analysis of variance. The variance was computed with analysis of variance for random effects. The SEM was then converted into the minimal detectable change (MDC), which expresses the minimal magnitude of change that likely reflects true change rather than measurement error. The MDC of 95% was estimated from the SEM and calculated as 1.96 √ 2× SEM or 2.77 × SEM. The agreement was also determined by the Bland–Altman method.
Construct validity was assessed by calculating Pearson's correlation coefficients (r) between the FACS-G and four other FA-related self-report measures (FABQ-G, NPRS, RMDQ-G, and PHQ-9) and then comparing the extent to which expected relationships between these various constructs were fulfilled. The r values yield the degree of correlation between two measures where 0 = no correlation between two scores and 1 or –1 = the absolute correlation between two scores.
Pearson's correlation coefficients are interpreted as follows: 0.00–0.19 = very weak correlation, 0.20–0.39 = weak correlation, 0.40–0.69 = moderate correlation, 0.70–0.89 = strong correlation, and 0.90–1 = very strong correlation.,
All statistical analyses were performed with SPSS software version 20.0 and Microsoft Office Excel 2007. The level of statistical significance was set at P < 0.05.
| Results|| |
Phase I: Cross-cultural adaptation process
The research team determined that the cross-cultural adaptation process was successful, and the results of the cognitive debriefing stage indicated that the perceived meaning of the questions was uniformly consistent with the intended meaning of the questionnaire. Since the prefinal version performed fine in the pilot test, it was acknowledged as the final version of the questionnaire.
Phase II: Evaluation of content validity
The panel of 30 bilingual experts “mostly agreed” to “strongly agreed” about the content equivalence of items between the FACS-G and the original English version. Content relevance fell between “mostly agree” to “strongly agree,” and content representativeness fell between “good” to “very good.”
Part III: Psychometric evaluation process
Characteristics of the study sample
The 150 patient samples included 47 males and 103 females, with an age range of 30–60 years. A variety of occupations were represented, including homemakers – 103 (68.7%), businessmen – 15 (10%), diamond workers – 3 (2%), office workers – 18 (12%), and teachers – 11 (7.3%). The additional characteristics of the participants are given in [Table 1].
|Table 1: Characteristics of chronic musculoskeletal pain disorder patients (n=150)|
Click here to view
The total scores were normally distributed, with a range of 3–85, mean of 41.21, and standard deviation (SD) of 17.29. The percentage of missing items was < 5%. Floor/ceiling effects were negligible. The percentage of patients who scored within each severity range is represented in [Figure 2].
|Figure 2: Graphical presentation of Fear-Avoidance Components Scale-G severity levels|
Click here to view
Reliability, internal consistency, and agreement
The test–retest analysis yielded an excellent result with very narrow confidence interval (CI) (ICC = 0.923 [95% CI = 0.837–0.963]) [Table 2]. The FACS-G exhibited excellent internal consistency shown by a Cronbach's alpha value of 0.834 (0.793–0.871). The item-wise Cronbach's alpha ranged between 0.818 and 0.835 [Table 3]. The Bland and Altman plot indicated that the measure of within-subject variation (i.e., the bias) was very minimal, as the mean difference was close to zero (mean difference [d] = −0.03), and the limits of agreement were excellent (+21.53 to − 21.59), with very few outliers [Table 2] and [Figure 3]. The Bland–Altman analysis showed that the mean difference was − 0.03 ± 11.0 for the FACS-G, respectively [Table 2] and [Figure 3]. The SEM for the FACS-G was 4.786. Calculations revealed an MDC of 13.27 points for FACS-G (scale range = 0–100).
|Figure 3: Bland and Altman plot for measuring the limits of agreement of Fear-Avoidance Components Scale-G scores|
Click here to view
All the correlations were significant (P ≤ 0.001) and followed expected constructed relationships hypothesized a priori [Table 4]. The FACS-G scores correlated strongly with the FABQ-G scores (r = 0.705). The FACS-G scores correlated moderately with both RMDQ-G (r = 0.615) and NPRS scores (r = 0.521; P < 0.01). The FACS-G scores had a lower correlation with the PHQ-9 scores (r = 0.461).
| Discussion|| |
This study aimed to translate the original English version of the FACS questionnaire into Gujarati and then to test the psychometric properties of the FACS-G. The translation procedure was conducted according to standard guidelines for cross-cultural adaptation., A cognitive debriefing interview with 20 patients indicated that they understood the meaning of each translated item without any difficulty. In the opinion of 30 bilingual experts who were surveyed, the content validity between the English and Gujarati FACS versions was determined to be good.
The total scores of the FACS-G in a sample of 150 patients ranged from 3 to 85, with a mean of 41 and a SD of 17.29. A variety of mean FACS values have been reported in other studies. Neblett et al. reported a mean of 67.9 (SD = 19.4) in an English-speaking sample of 419 CMPD patients. Knezevic et al. reported a mean of 54.93 (SD = 22.71) in a Serbian-speaking sample of 322 general chronic pain patients. Cuesta-Vargas et al. reported a mean of 30.49 (SD = 17.18) in a Spanish-speaking sample of 330 CMPD patients. The variation in these mean values is likely due to differences in culture, study population, pain chronicity, and sample size.
The high internal consistency value of the FACS-G (α = 0.835; Factor 1α = 0.800 and Factor 2α = 0.670) was consistent with the original English version (α = 0.92), Serbian version (Factor 1α = 0.904 and Factor 2α = 0.880), and Spanish version (Factor 1α = 0.904 and Factor 2α = 0.880). The fact that the Cronbach's alpha was less than 0.95 supports the current format of FACS-G, as a very high Cronbach's alpha would indicate redundancy of items.
The high test–retest reliability value (ICC = 0.923) was comparable to the ICC reported for the original English version (0.90) and the Serbian version (ICC2,1 = 0.928) (ICC for the Spanish version has not been reported). This evidently supports the repeatability of the results of the FACS-G, which is one of the important measurement properties required for any instrument. The narrow CIs that were obtained for the ICCs clearly indicate that this questionnaire can produce reliable results when administered on multiple occasions. The Bland and Altman analysis determined that all measurements fell within the 95% CI around the mean indicating a very strong agreement between the scores obtained at the two occasions with very minimal within-subject variation, strongly backing up the ICCs found.
The SEM and MDC provide clinicians and researchers with some guidance for true changes in a measurement in response to a treatment intervention, which are not attributed to random measurement error. The results revealed an MDC of 13.27 points for the FACS-G, suggesting that scores at or above this MDC values are likely due to patient improvement rather than measurement error. MDC values in the original English study, Serbian study, and Spanish study were not reported.
The lack of established clinically relevant severity cutoff values has been identified as a major weakness of other popular FA-related patient-reported outcome measures., Therefore, Neblett et al. proposed severity levels to help guide clinical interpretation of the FACS, with the goals of equal score ranges between each severity cutoff, providing ease of interpretation and assuring face validity. These severity levels (0–20, subclinical; 21–40, mild; 41–60, moderate; 61–80, severe; and 81–100, extreme) corresponded well with the score distribution in our study sample, with the majority of scoring within the mild (37.3%) to moderate (33.0%) ranges.
To help assess construct validity, correlations were determined between the FACS-G and a similar measure of FA (the FABQ-G), two symptom variables directly related to FA (pain severity ratings and perceived disability), and the related but separate variable of depressive symptoms. As expected, the FACS-G correlated highest with the FABQ-G and lowest with depressive symptoms (measured with the PHQ-9). The FACS-G correlated moderately with perceived disability (measured with the Roland-Morris Disability Questionnaire [RMDQ]) and pain severity (measured with a Numerical Pain Rating Scale). In a similar study by Knezevic et al., positive correlations were found between the FACS-Serb and the PCS, Beck Depression Inventory (BDI), State-Trait Anxiety Inventory, Oswestry Disability Index (ODI), and pain intensity scores. As with the present study, the highest correlation was found between the FACS-Serb and the PCS, which also measures components of FA. After dividing their study sample into severity groups, Neblett et al., found that higher FACS scores were associated with higher scores on the TSK, ODI, BDI, Insomnia Severity Index, and the Pain Disability Questionnaire, a measure of perceived disability. Cuesta-Vargas et al. reported a correlation between the FACS-Sp and the Central Sensitization Inventory, a measure of symptoms related to central sensitization, which have previously been found to be associated with FA. All four of these studies have now demonstrated evidence of convergent validity of the FACS by its associations with other FA-related symptoms.
As with other studies of this kind, there were some limitations. Since only CMPD patients were used to validate the FACS-G, there is a potential issue of generalizability of the findings. Other FA-related patient-reported outcome measures have been used in a wide variety of other patient populations, such as those with osteoarthritis, whiplash, burn pain, or sports injuries. Because FACS score distributions are unknown in these other populations at present, score interpretations should be made with caution. Patients with CMPDs often differ from many other chronic pain populations in that they are associated with moderate to high rates of disability, central sensitivity syndromes, and psychosocial overlay (e.g., depression and anxiety).,,,,
| Conclusion|| |
This study demonstrates that the FACS-G was effectively translated and cross-culturally adapted from English to Gujarati. The results of the present study indicate that the FACS-G is a psychometrically strong and highly reliable measure for Gujarati-speaking CMPD patients. Its psychometric properties were similar to the English, Spanish, and Serbian versions. It is hoped that both total FACS-G scores, suggesting one's general level of FA, and responses to individual FACS-G items can provide clinically relevant information to help health-care providers identify FA-related barriers to recovery and to measure treatment responsiveness of FA-related symptoms. Future studies should validate the FACS-G in other clinical populations who are likely to demonstrate the FA phenomena. Factor analysis, discriminant power, and treatment responsiveness of the FACS-G should also be evaluated in further studies.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Neblett R, Mayer TG, Williams MJ, Asih S, Cuesta-Vargas AI, Hartzell MM, et al
. The fear-avoidance components scale (FACS): Responsiveness to functional restoration treatment in a chronic musculoskeletal pain disorder (CMPD) population. Clin J Pain 2017;33:1088-99.
Neblett R, Mayer TG, Hartzell MM, Williams MJ, Gatchel RJ. The fear-avoidance components scale (FACS): Development and psychometric evaluation of a new measure of pain-related fear avoidance. Pain Pract 2016;16:435-50.
Lundberg M, Grimby-Ekman A, Verbunt J, Simmonds MJ. Pain-related fear: A critical review of the related measures. Pain Res Treat 2011;2011:494196.
Miller R, Kori S, Todd D. The Tampa scale: A measure of Kinesiophobia. Clin J Pain 1991;7:51-2.
Waddell G, Newton M, Henderson I, Somerville D, Main CJ. A fear-avoidance beliefs questionnaire (FABQ) and the role of fear-avoidance beliefs in chronic low back pain and disability. Pain 1993;52:157-68.
McCracken LM, Zayfert C, Gross RT. The pain anxiety symptoms scale: Development and validation of a scale to measure fear of pain. Pain 1992;50:67-73.
Vlaeyen JW, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: A state of the art. Pain 2000;85:317-32.
Brede E, Mayer TG, Neblett R, Williams M, Gatchel RJ. The Pain Anxiety Symptoms Scale fails to discriminate pain or anxiety in a chronic disabling occupational musculoskeletal disorder population. Pain Pract 2011;11:430-8.
Neblett R, Hartzell MM, Mayer TG, Bradford EM, Gatchel RJ. Establishing clinically meaningful severity levels for the Tampa Scale for Kinesiophobia (TSK-13). Eur J Pain 2016;20:701-10.
Knezevic A, Neblett R, Gatchel RJ, Jeremic-Knezevic M, Bugarski-Ignjatovic V, Tomasevic-Todorovic S, et al
. Psychometric validation of the Serbian version of the Fear Avoidance Component Scale (FACS). PLoS One 2018;13:e0204311.
Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health-related quality of life measures: Literature review and proposed guidelines. J Clin Epidemiol 1993;46:1417-32.
Cuesta-Vargas AI, Neblett R, Gatchel RJ, Roldán-Jiménez C. Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care. BMC Fam Pract 2020;21:44.
Bid D, Ramalingam A, Sinha S, Rathi P, Patel V, Rajwani J, et al
. Cross-cultural adaptation, reliability, validity, and factor analysis of the Gujarati version of the Tampa scale of kinesiophobia in chronic low back pain. Physiother J Indian Assoc Physiother 2018;12:79-86.
Bid DD, Soni NC, Rathod PV, Ramalingam AT, Sinha RK. Cross cultural adaptation, reliability and validity of gujarati version of fear avoidance belief questionnaire in chronic low back pain. NJIRM 2016;7:1-8.
Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine (Phila Pa 1976) 2000;25:3186-91.
Nambi SG. Reliability, validity, sensitivity and specificity of Guajarati version of the Roland-Morris Disability Questionnaire. J Back Musculoskelet Rehabil 2013;26:149-53.
Roland M, Fairbank J. The roland-morris disability questionnaire and the oswestry disability questionnaire. Spine (Phila Pa 1976) 2000;25:3115-24.
Childs JD, Piva SR, Fritz JM. Responsiveness of the numeric pain rating scale in patients with low back pain. Spine (Phila Pa 1976) 2005;30:1331-4.
Kroenke K, Spitzer RL, Williams JB. The PHQ-9: Validity of a brief depression severity measure. J Gen Intern Med 2001;16:606-13.
Deyo RA, Diehr P, Patrick DL. Reproducibility and responsiveness of health status measures. Statistics and strategies for evaluation. Control Clin Trials 1991;12:142S-158S.
Streiner D, Norman G. Health Measurement Scales: A Practical Guide to Their Development and Use. 4th
ed.. Oxford: Oxford University Press; 2008.
Portney L, Watkins M. Foundation of Clinical Research: Applications to Practice. Upper Saddle River, NJ: Prentice-Hall; 2000.
Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1:307-10.
Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res 1999;8:135-60.
Terwee CB, Bot SD, de Boer MR, van der Windt DA, Knol DL, Dekker J, et al
. Quality criteria were proposed for measurement properties of health status questionnaires. J Clin Epidemiol 2007;60:34-42.
Hopkins WG. Measures of reliability in sports medicine and science. Sports Med 2000;30:1-5.
Fowler J, Chevannes M, Jarvis P. Practical Statistics for Nursing and Health Care. New York, Chichester: Wiley; 2002.
Neblett R. The central sensitization inventory: A user's manual. J Appl Biobehav Res 2018;23:e12123.
Heuts PH, Vlaeyen JW, Roelofs J, de Bie RA, Aretz K, van Weel C, et al
. Pain-related fear and daily functioning in patients with osteoarthritis. Pain 2004;110:228-35.
Bunketorp L, Lindh M, Carlsson J, Stener-Victorin E. The effectiveness of a supervised physical training model tailored to the individual needs of patients with whiplash-associated disorders-a randomized controlled trial. Clin Rehabil 2006;20:201-17.
Willebrand M, Andersson G, Kildal M, Gerdin B, Ekselius L. Injury-related fear-avoidance, neuroticism and burn-specific health. Burns 2006;32:408-15.
Kvist J, Ek A, Sporrstedt K, Good L. Fear of re-injury: A hindrance for returning to sports after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2005;13:393-7.
Matre D, Knardahl S. 'Central sensitization' in chronic neck/shoulder pain. Scand J Pain 2012;3:230-5.
Bid D, Soni N, Rathod P. Central sensitization in chronic low back pain: A narrative review. Natl J Integ Res Med 2016;7:114-23.
Sanzarello I, Merlini L, Rosa MA, Perrone M, Frugiuele J, Borghi R, et al
. Central sensitization in chronic low back pain: A narrative review. J Back Musculoskelet Rehabil 2016;29:625-33.
Shigetoh H, Tanaka Y, Koga M, Osumi M, Morioka S. The mediating effect of central sensitization on the relation between pain intensity and psychological factors: A cross-sectional study with mediation analysis. Pain Res Manag 2019;2019:1-6.
Tanaka K, Murata S, Nishigami T, Mibu A, Manfuku M, Shinohara Y, et al
. The central sensitization inventory predict pain-related disability for musculoskeletal disorders in the primary care setting. Eur J Pain 2019;23:1640-8.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]