|Year : 2018 | Volume
| Issue : 2 | Page : 79-86
Cross-cultural adaptation, reliability, validity, and factor analysis of the Gujarati version of the Tampa scale of kinesiophobia in chronic low back pain
Dibyendunarayan Dhrubaprasad Bid1, A Thangamani Ramalingam1, Saumi R Sinha2, Payal B Rathi1, Vidhi N Patel1, Jainab M Rajwani1, Krutika N Patel1
1 Department of Musculoskeletal Physiotherapy, Sarvajanik College of Physiotherapy, Surat, Gujarat, India
2 Department of Cardiopulmonary Physiotherapy, Shri B. G. Patel College of Physiotherapy, Anand, Gujarat, India
|Date of Submission||11-Jan-2018|
|Date of Acceptance||18-Sep-2018|
|Date of Web Publication||17-Dec-2018|
Dr. Dibyendunarayan Dhrubaprasad Bid
Department of Musculoskeletal Physiotherapy, Sarvajanik College of Physiotherapy, Rampura, Surat - 395 003, Gujarat
Source of Support: None, Conflict of Interest: None
BACKGROUND: Nowadays more attention is being given to standardizing the outcome measures for improving treatment methods for chronic low back pain (CLBP). The Gujarati translation of the Tampa scale of kinesiophobia (TSK) in patients with CLBP has never been validated in the native Gujarati population.
PURPOSE: Translating, culturally adapting, and validating the Gujarati version of the TSK-Gujarati (TSK-G) to allow its use for Gujarati-speaking patients with CLBP.
MATERIALS AND METHODS: The development of the TSK-G questionnaire involved its translation and backtranslation, a final review by an expert committee, and testing of the pre final version in establishing its correspondence to the original English version. The psychometric testing included reliability by internal consistency (Cronbach's
α), test-retest reliability (intraclass coefficient correlation [ICC]), convergent and divergent validity (Pearson's correlation) by comparing TSK-G to a numerical pain rating scale, fear-avoidance beliefs questionnaire (FABQ), the Roland Morris disability questionnaire (RMDQ), and patient health questionnaire-9 (PHQ-9); and factor analysis.
RESULTS: Factor analysis indicated a 6-factor 17-item solution (64.07% of explained variance). The questionnaire showed satisfactory internal consistency (0.639) and moderate test-retest reliability (ICC 0.696). Divergent validity showed low correlations with numerical pain rating scale (r = 0.044), the RMDQ-G (r = 0.06), and PHQ-9-G (r = 0.269); but convergent validity showed highly significant correlation with FABQ-G (r = 0.407, P = 0.001).
CONCLUSION: The successful translation of TSK questionnaire into the Gujarati language shows good psychometric properties and factorial structure and approximates the results of the current English version of the TSK questionnaire.
Keywords: Chronic low back pain, factor analysis, psychometric properties, reliability, Tampa scale of kinesiophobia, validity
|How to cite this article:|
Bid DD, Ramalingam A T, Sinha SR, Rathi PB, Patel VN, Rajwani JM, Patel KN. 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
|How to cite this URL:|
Bid DD, Ramalingam A T, Sinha SR, Rathi PB, Patel VN, Rajwani JM, Patel KN. 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 [serial online] 2018 [cited 2019 May 22];12:79-86. Available from: http://www.pjiap.org/text.asp?2018/12/2/79/247606
| Introduction|| |
In 1990 Miller, Kori and Todd introduced the term kinesiophobia to describe a situation where “a patient has an excessive, irrational, and debilitating fear of physical movement and activity resulting from a feeling of vulnerability to painful injury or re-injury.”,
The Tampa scale of kinesiophobia (TSK) was at first developed in American English and then validated across a number of English speaking populations. After that TSK has been effectively translated and validated in multiple languages worldwide.,,,,,,,,,,, The multicenter research studies done internationally needs cross-culturally adapted questionnaires with stable measurement properties for a particular linguistic population before use.
When looking at the patient from an Indian context, English is not commonly followed in most of the regions of India; the language acts as a barrier putting a restraint to the usage of English and other western versions of TSK. The availability of non-English versions of fear of movement questionnaires offers a standard measure for use in international studies and clinical practice and allows clinicians and researchers to share clinical outcomes and information. In India, there are 46, 091, 617 (i.e., 4.48% of India's population) people, who speak Gujarati as their first language. As per Encarta 2007 estimate, there are 46.1 million Guajarati speakers worldwide. Till date, there is no Gujarati version of TSK available to assess the fear of movement for Gujarati speaking chronic low back pain (CLBP) sufferers.
Hence, the aim of this study was to fulfill the procedure of cross-cultural adaptation and also testing the psychometric properties of TSK in the Gujarati language.
| Materials and Methods|| |
Native Gujarati patients with CLBP were recruited for the study with age group 25–75 years, of both genders, having back pain for more than 3 months and were able to read and write the Gujarati. They were recruited from various physiotherapy outpatient departments in Surat, Gujarat, India. Patients were excluded if they had back pain because of vertebral fracture, myelopathy, brain surgery, back surgery, clinically identifiable cognitive impairment, infectious disease, cardiovascular or respiratory problems, neurological deficits, cancer, or other systemic diseases with a possible effect on the musculoskeletal system. Written informed consent was taken from each patient before participation.
Tampa scale of kinesiophobia
The TSK is a 17-item questionnaire used to assess the subjective rating of fear of movement or kinesiophobia.,, It is a self-completed questionnaire and which has a range of scores from 17 to 68 where the higher scores point toward an increasing degree of kinesiophobia.
Vlaeyen et al. developed a cutoff score where a score of 37 or above is considered as a high score, while scores below that are understood as low scores. Use of a total score (including all 17 items) is suggested, although medical practitioner may wish to interpret results using two subscales: “activity avoidance – this subscale reflects the belief that activity may result in (re) injury or increased pain, and somatic focus – reflects the belief in underlying and serious medical problems.”
Fear-avoidance beliefs questionnaire-Gujarati
Waddell et al. developed fear-avoidance beliefs questionnaire (FABQ) to measure FABs 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” and factor analysis showed two subscales, one subscale focused on patients beliefs about how physical activities affect their pain (FABQ-PA) and the other focused on patient's beliefs about how work affects their pain (FABQ-W).,, In this study, FABQ Gujarati version was used. The FABQ has been proved to be reliable and valid in a CLBP population.
Numerical pain rating scale
A two-point change on the numerical pain rating scale (NPRS) represents the clinically meaningful change that exceeds the limits of measurement error.
Roland Morris Disability Questionnaire
Internal consistency of the Roland Morris disability questionnaire (RMDQ)-G is found to be adequate (>0.65) at both times, with high intra-class correlation coefficient (ICC's) also at both time points. Internal construct validity of the scale is good, indicating a single underlying construct. Hence, the Gujarati version of RMDQ is considered reliable and valid.
Patient health questionnaire-9
This is a self-administered instrument. The Patient Health Questionnair-9 (PHQ-9) is the depression module, which scores each of the 9 items as “0” (not at all) to “3” (nearly every day). PHQ-9 scores of 5, 10, 15, and 20 represented mild, moderate, moderately severe, and severe depression, respectively.
The translation procedure was based on previously published guidelines, and methodology has been shown in [Figure 1]. The Gujarati translation of TSK-G is given in [Appendix-1].
This was assessed by an expert panel of 30 healthcare professionals comprising of physicians, orthopedic surgeons, neurologists, psychiatrists, nurses, and physiotherapists. They assessed the translated Tampa scale of kinesiophobia - Gujarati (TSK-G) for “content equivalence”, “content relevance” and “content representativeness” on a Likert scale of 0 to 6 (a 7-point scale). Potential floor and ceiling effects were thought to be present if more than 15% of the respondents attained the highest or lowest possible score, respectively.
Exploratory factor analysis was performed to determine the dimensionality of the items of the questionnaire. Factor structure was evaluated using principal component analysis with varimax rotation method. Eigen-values ≥1 were retained and items with loadings ≥0.4 were considered acceptable.
Internal consistency of the TSK-G was examined with Cronbach's α coefficient. Cronbach's α values range from 0 to 1, where values above 0.7 indicate adequate internal consistency for a scale.
Test-retest reliability of the questionnaire was performed on 30 subjects for the TSK-G. Subjects completed the relevant questionnaire twice with an interval of 48 h to reduce any memory of previous answers and any variations in clinical status. Test-retest reliability was determined by ICC. ICCs can vary from 0 to 1 and values above 0.8 are considered as proof of excellent reliability.
The standard error of measurement (SEM) was used to decide the measurement error. The SEM is calculated 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 95% was estimated from the SEM and calculated as 1.96 √ 2× SEM. The agreement was also calculated by the Bland-Altman method.
Construct validity is frequently measured as convergent and divergent validity and factor analysis. In this study, convergent validity was evaluated by a parallel questionnaire FABQ-G. Divergent validity was tested by Pearson correlation coefficients by showing that the TSK-G measurement concept is different from that for severity of pain on NPRS, disability (RMDQ-G) and depression (PHQ-9). In addition, factor analysis was done for construct validity. Construct validity was assessed by calculating Pearson's correlation coefficients (r) comparing the extent to which expected relationships between the various constructs were fulfilled using the TSK-G. Expected relationships were based on the literature. 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.,
Based on previous studies with similar objectives and our clinical experience, we hypothesized the following relationships between the various constructs a priori:
- TSK-G and FABQ-G would have a high correlation
- TSK-G and PHQ-9 would have low-to-moderate correlation
- NPRS would have low-to-moderate correlations with TSK-G
- TSK-G and RMDQ-G would have low-to-moderate correlations.
Ethical approval was not sought as this study was nonexperimental in nature.
Data were checked for normality using Kolmogorov-Smirnov test. Descriptive statistics (percentages, means, and standard deviations) were used to describe demographic characteristics within the study. All analyses of reliability and validity described in the research methods were conducted using SPSS version 20.0 (IBM, Armonk, NY, USA) for Windows with a 95% confidence interval (CI).
| Results|| |
A total of 160 patients with CLBP (male-52, and female-108) participated in the study. The demographic characteristics of the patients are presented in [Table 1].
Content equivalence was assessed under two headings:
- Are the words in the translated Gujarati version presented fluently and correctly as in the original version? For this answers from 30, expert panel members fall between “mostly agree” to “strongly agree” (average = 5.4) on a 7-point Likert scale (0–6)
- Do the words and phrases in the translated Gujarati version have the same semantic meaning compared with the original version? For this answers from 30, expert panel members fall between “mostly agree” to “strongly agree” (average = 5.3) on a 7-point Likert scale (0–6).
Content relevance is assessed by asking this question: How the Gujarati statement is relevant to assessing fear of movement in CLBP patients? For this answers from 30, expert panel members fall between “mostly agree” to “strongly agree” (average = 5.67) on a 7-point Likert scale (0–6).
Content representativeness was assessed by asking “How well is the content (Item No. 1–17) of TSK-G scale is representing the entire domain of assessing the fear of movement of patients with CLBP?” For this answers from 30 expert panel members falls between “Good” to “very good” on a 7-point Likert scale (0–6) (average = 5.52). In addition, the total scores were normally distributed and the percentage of missing items were <5%, also proves the content validity of this questionnaire. There was no floor and ceiling effect found.
The total score ranged between 17 and 68 for TSK-G. In this study, 136 (85%) of patients out of 160 with CLBP were found having a high level of kinesiophobia. The TSK-G exhibited moderate internal consistency shown by a Cronbach's α value of 0.639. Test-Retest reliability of the TSK-G analyzed on stable subjects (n = 30) yielded moderate results with a very wide confidence intervals (ICC = 0.696 [95% CI = 0.362–0.855]) and item-wise ICC ranged from 0.214–0.804 [Table 2] and [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] = −0.6) and the limits of agreement were excellent between −9.26 and 8.06. The SEM for the TSK-G was 2.431. Calculations revealed an MDC of 6.74 points for TSK-G (scale range = 17–68). The Bland-Altman analysis showed that the mean difference was −0.6 ± 4.42 for the TSK-G [Graph 1].
The construct validity analysis showed that TSK-G total score was significantly correlated with FABs and depression; however, there were no correlations obtained for pain and functional status [Table 4].
Six factors were extracted for the TSK-G, which accounted for 64.09% of the total variance in the principal component analysis (PCA) with varimax rotation [Table 5]. Two factors and three-factor models showed only 31.33% and 41.88% of total variances, respectively. A TSK-G scale with 13-items after removing items 4, 8, 12, and 16 showed 57.94% of total variance with the extraction of four factors.
|Table 5: Varimax rotated factor loading matrix of the Tampa Scale of Kinesiophobia-Gujarati (n = 160)|
Click here to view
| Discussion|| |
The results indicated that the TSK-G was a reliable instrument that could be used in the future to detect a fear of movement due to chronic back pain in Gujarati populations.
The TSK-G revealed excellent content validity in the context of “content equivalence”, “content relevance” and “content representativeness.” The internal consistency value of the TSK-G (0.639) was adequate; however, it was lower than the English version (0.84) and other translated versions in German (0.73), Italian (0.772), Norwegian version (alpha = 0.81 in sciatica due to disc herniation), and Chinese version (0.82). The fact that the Cronbach's α was <0.95 supports the current format of TSK-G, as a very high Cronbach's α would indicate redundancy of items.
In our study, the test-retest reliability value for TSK-G was moderate (ICC = 0.696) which was close to the ICC reported for the English version of TSK (0.84) but Italian version (ICC = 0.956, 95% CI) and Brazilian-Portuguese version (ICC = 0.93, 95% CI) showed highly significant correlation. This supports the reproducibility of the results of the TSK-G which is one of the important measurement properties required for any questionnaire.
The fact that almost all measurement fell within the 95% CI around the mean difference during the Bland and Altman analysis points out to a strong agreement between the scores obtained on the two occasions with very minimal within-in subject variation, strongly backing up the ICC's obtained. The SEM and MDC provide clinicians and researchers with some guidance for true changes in the measurements, which are not random measurement error. The results revealed an MDC of 6.74 points for the TSK-G (scale range = 17–68). Scores at or above this MDC values are likely due to patient improvement rather than measurement error. Estimated minimal meaningful changes should be larger than the MDC values.
The factor analysis was conducted to determine whether all items of the questionnaire would be grouped into some pattern. Six factors for the TSK-G were extracted using PCA with varimax rotation. Removing a few items and making it an 11 or 13 items scale would not provide enough factorial dimension reduction with more percentage of total variance as a scale.
This point out that all the 17-items explains the kinesiophobia in the multidimensional structure of the CLBP patients. Burwinkle et al. stated that as the factor analyses have generated inconsistent findings regarding the number of factors and the items that comprise them; so the content validity of TSK can be interrogated. Vlaeyen et al. subjected the Dutch version of TSK to a PCA with oblique rotation, which generated a four-factor solution.
However, Lundberg et al. obtained a 5-factor solution based on the 17-item Swedish version of TSK. Our findings also clash with the 3-factor solution of the Norwegian version, possibly because of the difference in sample selection (patients with sciatica rather than CLBP). The Cronbach's α and ICC values for the TSK-G were moderate. The results of the factor analysis suggested that the TSK-G is a multidimensional measure.
As the NPRS measures pain intensity; and TSK-G fear of movement, the rather high correlations between NPRS scores and TSK-G scores were not expected. As it is found in our study, there was a very weak correlation (Pearson's correlation coefficient = 0.04) between NPRS and TSK-G. The very weak correlation between TSK-G and NPRS can be explained by the fact that fear of movement is not directly related to the level of pain. French found little correlation between the TSK and a visual analog scale (r = 0.23), as did Swinkels-Meewisse (Harm r = 0.10; activity avoidance r = 0.18) and Haugen (r = 0.15–0.18). The limits of agreement for the measurements were large.
Our study showed a moderate correlation (r = 0.407) between TSK-G and FABQ-G. Wei et al. also showed similar moderate correlation (r = 0.58). A moderate-to-good correlation between TSK and FABQ can be construed as – “pain beliefs have a role in generating kinesiophobia among CLBP patients”. Similarly, French et al. also showed a moderate correlation between TSK and FABQ-PA (r = 0.53) and FABQ-W (r = 0.35). In the fear-avoidance model of pain and disability proposed by Vlaeyen et al., it is suggested that pain catastrophizing may influence patients toward the development of kinesiophobia which in turn, may lead to augmented disability and a worsening of the overall pain experience.
Our study showed no correlation (r = 0.06, P = 0.451) between TSK-G and RMDQ-G. In another study, investigators found a moderate correlation between the TSK-I and the RMDQ, which can be explained as the peculiarity of the fear of movement domain within the biopsychosocial model.
Our study showed a weak correlation (r = 0.269) between TSK-G and PHQ-9. Similarly, a study by Tkachuk and Harris showed that there is a weak correlation between TSK and Beck depression inventory (BDI)-II (r = 0.38). The BDI-II (2nd Edition) also measures depression severity. Overall, the observed psychometric properties were consistent with those reported both for the English and other translated versions.
Small sample size and the use of convenience sampling could be considered as limitations of this study that may restrict the generalization of the findings. Another limitation is that only self-report measures were used in this study. As indicated in an earlier study, future research should use physical performance tests to search the types of activities that are avoided by patients. Responsiveness of the TSK-G should be evaluated in further studies.
| Conclusion|| |
The Gujarati translation of TSK was successful, and it shows a good factorial structure and psychometric properties, and it is found to be a reliable and valid measure to assess the fear of movement or kinesiophobia in Gujarati-speaking CLBP patients.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]