VALIDATION OF THE PORTUGUESE VERSION OF THE TAMPA SCALE FOR KINESIOPHOBIA HEART ( TSK-SV HEART )

Gabriela Lima de Melo Ghisi1 (Physiotherapist) Rafaella Zulianello dos Santos2 (Physical Education Professional) Thiago Renee Felipe3,6 (Physical Education Professional) Christiani Decker Batista Bonin2 (Physiotherapist) Edson Fonseca Pinto3,4 (Physical Education Professional) Felipe Eduardo Fernandes Guerra5 (Doctor) Maria Irany Knackfuss3 (Physical Education Professional) Paul Oh1 (Doctor) Magnus Benetti2 (Physical Education Professional)


INTRODUCTION
Coronary Artery Disease (CAD) is the leading cause of death worldwide in women and men 1 . Cardiac rehabilitation (CR) has a significant impact on morbidity and mortality among patients with documented CAD, improving functional capacity and decreasing re-hospitalization and overall medical costs [2][3][4] . Cardiac rehabilitation has been formally defined as "the enhancement and maintenance of cardiovascular health through individualized programs designed to optimize physical, psychological, social, vocational and emotional status" 5 .
Cardiac rehabilitation is a complex intervention that may involve a variety of therapies, including the facilitation and delivery of secondary prevention through risk factor identification and modification in an effort to prevent disease progression and the recurrence of cardiac events 5,6 . Nonetheless, international clinical guidelines consistently identify exercise therapy as a central element of CR programs [5][6][7][8][9] . Previous meta-analysis 2-4,10-12 showed that exercise-based CR programs reduce significantly the number of non-fatal MI, cardiac death, and total mortality. Despite these benefits, CR programs are greatly underutilized, with rates of enrollment around 14% in middle-income countries 13 such as Brazil.
According to Back et al. 14 , there is a need to identify obstacles that prevent patients from participants in CR and increasing their levels of physical activity. In this context, the Tampa Scale for Kinesiophobia (TSK) 15 -the only questionnaire that has been specifically designed to measure kinesiophobia -was validated to detect kinesiophobia in CAD patients (TSK-SV Heart) 14 . Kinesiophobia is "a condition in which 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" 16 . Based on clinical experience, kinesiophobia can be a barrier to enroll and participate in CR programs once CAD patients often have doubts that physical activity can be performed safely after the diagnosis 14 . The TSK-SV has not been tested for the psychometric properties in the Brazilian population.
The objective of this study was to translate, culturally adapt and psychometrically validate the tsk-sv heart to portuguese.

This study was reviewed and approved by the Ethics and Research
Board of the State University of Santa Catarina (number 497.256), in accordance with CNS's resolution 196/96. The design of this study consisted of a series of cross-sectional, observational studies.
First, the translation and cultural adaptation was performed. This process followed strict norms approved by the author and co-authors and was based on the protocol proposed by Guillemin et al. 17 : (1) initial translation, (2) back-translation, (3) committee review of those translations and back-translations, (4) pre-testing for equivalence using bilingual individuals, and (5) reexamination of the weighting of scores. The initial translation was performed by three independent translators, all aware of the objectives and concepts underlying the study and sought to detect ambiguities and unexpected meanings in the original items. The back-translation was performed by a forth translator, blinded to the initial objectives of the study and the original version. A committee of five bilingual experts reviewed all versions and a final version was generated. This version was then pre-tested in 30 patients. Results were used to refine the Portuguese version of the TSV-SV Heart.
Second, a psychometric validation was performed. The refined tool was administered to a larger sample of current CR participants from three programs in the Greater Florianopolis Area (Santa Catarina, south of Brazil), and one program in Natal (Rio Grande do Norte, north of Brazil). The instrument was applied through monitored self-administration. The researchers maintained a neutral stance during the administration, answering questions about the research and encouraging participants to answer all questions. The questionnaire was re-administered two weeks after the first application in 28 randomly selected participants to assess test-retest reliability. Data were collected between February and July of 2014.
For the psychometric validation, a convenience sample of 300 current CR patients was recruited from four institutions in 2 regions of Brazil (in the Northeast 1 private and in the South of Brazil 1 private and 2 public ones). These programs have a minimum duration of 3 months and no structured educational component. The inclusion criteria were the following: confirmed CAD diagnosis or multiple cardiovascular risk factors. The exclusion criteria were the following: younger than 18 years old, illiterate, any significant visual, cognitive or mental impairment which preclude the participant's ability to answer the questionnaire.
The Tampa Scale for Kinesiophobia (TSK) was designed to measure kinesiophobia in patients with persistent musculoskeletal pain 15 and has been found to be reliable and valid for patients with CAD 14 . The TSK-SV Heart detects kinesiophobia in patients with CAD in four theoretical constructs or areas: danger, fear, avoidance, and dysfunction. The TSK-SV comprises 17 statements rated on a 4-point Likert-type scale that ranged from 1 = "strongly disagree" to 4 = "strongly agree", and accordingly higher scores indicated greater degree of kinesiophobia. A cut-off > 37 has been defined by Vlaeyen et al. 18 and used for coronary artery patients by Back et al. 14 as a high level of kinesiophobia.
Patients were characterized according to sex, age, educational level, family income, comorbidities, clinical risk factors, and duration of participation in CR. Participant clinical characteristics were obtained from the medical chart and socio-demographic characteristics were self-reported.
To test psychometric properties of the Portuguese TSK-SV Heart, it was investigated reliable measures as following: face and content validity, test-retest reliability, internal consistency, criterion validity, and a descriptive analysis.

Statistical analysis
The sample size calculation for the psychometric analysis was based on Hair and Anderson 19 recommendation of a minimum sample size of 10 subjects per item, and/or at least 100 participants. Since the TSK-SV Heart has 17 items, a sample size of 300 is considered valid.
To test face and content validity a pre-test in patients with CAD was performed to provide feedback on the items and to check the time required to complete the questionnaire. Furthermore, patients gave their opinion on the face validity. Five experts were also asked to assess the face validity of the Portuguese TSK-SV Heart as part of the committee of experts' assessment.
To assess test-retest reliability, we used intraclass correlation coefficient (ICC). Bad items (ICC values lower than 0.70) 20 were eliminated. Then, Cronbach's alpha was calculated for each subscale separately, in order to assess internal consistency. For this analysis, values higher than 0.70 were considered acceptable 20 , reflecting the internal correlation between items at the same area. The factor structure was an option of internal correlation assessment if the internal correlation between items in the areas was not confirmed.
Criterion validity was assessed by comparing TSK-SV Heart scores by gender 21 , level of education 22 , family income 22 , and duration in CR 23 . T-tests and Pearson's correlation were used as applicable. A descriptive analysis of the Portuguese version of the TSK-SV Heart was also performed. A mean total score was computed to reflect total kinesiophobia. Mean scores per area were also described. Differences in TSK-SV Heart scores based on socio-demographic and clinical characteristics were assessed. As subjects are rating importance, ceiling and floor effects are likely not applicable 20 .
The SPSS -Statistical Package for Social Sciences -release 21.0 24 was used for storing, sorting and analyzing data. The level of significance for all tests was set at 0.05. When more than 20% of the items were not completed by the participant, their data were excluded from the analysis.

RESULTS
For the psychometric validation, 300 current CR patients (85% of those approached to participate in this study) signed the consent form and completed the TSK-SV Heart in Portuguese. The socio-demographic and clinical characteristics of these participants are presented in Table 1. The sample was primarily male (n=207; 69%) and well-educated (University degree incomplete or higher, n=179; 60%). The mean age was 62.1±10.1 years old (min=37, max=81). To assess test-retest reliability, 28 of these patients were randomly selected and asked to complete the tool once more.
During the process of translation and cultural adaptation, it was observed that 1 item (number 13) needed to be grammatically adapted in order to be used to the Brazilian context. This change was related to changing terms in order to improve clarity (not changing the context): the word "heart" was replaced by "problem". No other changes were required.
The 30 participants took a mean of 13.4±1.9 minutes to complete the Portuguese TSK-SV Heart. In regards to content validity, after application and individual discussions between patients and researchers it was confirmed and the Portuguese TSK-SV Heart provides a clear description of the measurement aim, the target population, the concepts that are being measured, and the item selection.
As described elsewhere, the Portuguese version of the TSK-SV Heart was administered to 300 CR participants to assess psychometric properties. Mean scores and completion rates are shown in Table 2.
The test-retest reliability was evaluated through the intraclass correlation coefficient (ICC) for each item and results are shown in Table 2. Item 14 ("t is really not safe for a person in my condition to be physically active/ exercise") did not meet the minimum recommended standard 20 and, therefore, were excluded from the Portuguese version of the TSK-SV Heart.
Furthermore, the reliability of each area was assessed by Cronbach's alpha. All areas were considered internally consistent (α > 0.7). Table 2 also displays Cronbach's alpha of each area. The Cronbach's alpha of the instrument was 0.83.
With regard to criterion validity, total TSK-SV Heart scores were compared by gender, level of education, family income, and duration in CR. In this context, patients with lower family income and months in CR had significantly greater kinesiophobia compared with their counterparts (p<0.01). Surprisingly, patients with higher educational level presented significantly higher kinesiophobia than those with lower education (p<.001).

DISCUSSION
This study sought to validate the TSK-SV Heart and adapt it for Portuguese-speaking patients with CAD. Although the occurrence of kinesiophobia in patients with CAD is not known, this condition has been shown to have a negative influence in the outcome of rehabilitation and is consequently of importance in the clinical setting 23 . The validation of the Portuguese version of the TSK-SV Heart followed strict norms, since the process of adapting an instrument to be used by a different population requires a greater effort than simply translation and idiomatic and semantic analysis 17 . Psychometric properties -content validity, test-retest reliability, internal consistency, and construct validity -were all established, and demonstrated the validity of this tool in Brazil.
Results of this study were consistent with those presented in the original validation 14 , particularly in relation to test-retest reliability (ICC=0.83 14 vs 0.84) and internal consistency (Chronbach's alpha=0.78 14 vs 0.83). In regards to content validity, patients with lower family income had significantly greater kinesiophobia as described in the literature 22 . No differences were found regarding educational levels. Moreover, no differences between TSK-SV Heart scores and gender were observed. Although some studies assessing kinesiophobia and gender have reported that men have higher levels of kinesiophobia compared to women 21,25,26 , some of these results are considered equivocal and there are sparse data on cardiac patients to support this relationship. Finally, duration in CR (i.e. months participating in the program) showed inverse results compared to the literature 23 . In our study, patients that are participating in CR for more than 6 months had significantly greater kinesiophobia. One justification for this result is that participation and attendance are different things and patients can be register in the program but not attending and engaged. It is important to assess attendance in future studies.
Patient education is an important component of CR programs 5,6 and is related to successful patient self-management of CAD 27 and behavior change 28 . It has been shown to decrease adverse outcomes and even contribute to regression of the disease 29 . Items that comprise the Portuguese TSK-SV Heart should be included in the educational components of CR programs and discussed between patients and health providers. In addition, no studies have assessed the relationship between education and kinesiophobia, which is needed.
Caution is warranted when interpreting results. First, results are only generalizable to CR patients, which is a low proportion of CAD outpatients. Second, the test-retest was performed by 28 patients; however, a number of at least 50 is generally considered adequate. Third, there are some elements of the scale which require further assessment, such as construct validity related to behaviorally oriented constructs (as assessed in the original instrument 14 ). Moreover, future research is needed to assess whether the scale is sensitive to change, such as a longitudinal study assessing kinesiophobia before and after CR participation. Finally, whether the Portuguese TSK-SV Heart is a valid tool to assess kinesiophobia in non-CR patients with CAD should be explored.
All authors declare no potential conflict of interest related to this article.