The cross-cultural adaptation to Portuguese of the Dissociative Experiences Scale for screening and quantifying dissociative phenomena

Abstracts

OBJETIVO: Este artigo apresenta a adaptação transcultural para o português da Dissociative Experiences Scale, o questionário mais utilizado mundialmente para rastrear e quantificar os fenômenos dissociativos. MÉTODOS: Fizeram-se duas traduções e suas respectivas retraduções, avaliação da equivalência semântica, elaboração da versão síntese, pré-teste na população-alvo, realização da versão final e segundo pré-teste na população-alvo. RESULTADOS: Observou-se um grau elevado de equivalência semântica entre o instrumento original e os dois pares de traduções-retraduções, da perspectiva dos significados referencial e geral. Os pré-testes na população-alvo conduziram a modificações para confirmar a realização dos critérios de equivalência semântica e de equivalência operacional. CONCLUSÃO: Este trabalho torna disponível a primeira adaptação para o contexto brasileiro de um instrumento específico para a detecção e a quantificação de sintomas dissociativos.

Transtornos dissociativos; Questionários; Tradução (processo)

ORIGINAL ARTICLE

The cross-cultural adaptation to Portuguese of the Dissociative Experiences Scale for screening and quantifying dissociative phenomena

Adriana Fiszman^{I, II}; Mariana Cabizuca^II; Claudia Lanfredi^II; Ivan Figueira^{II, III}

^IInstitute of Psychiatry of the Federal University of Rio de Janeiro – UFRJ

^IIResearch Group on Stress-related Disorders of the Institute of Psychiatry of the Federal University of Rio de Janeiro – UFRJ

^IIIMedical School of the Psychiatry of the Federal University of Rio de Janeiro – UFRJ

^{Correspondence}

ABSTRACT

OBJECTIVE: This paper presents the cross-cultural adaptation to Portuguese of the Dissociative Experiences Scale, the worldwide most employed questionnaire for screening and quantifying dissociative phenomena.

METHODS: Two translations and their respective back-translations were performed, as well as the evaluation of the semantic equivalence, the preparation of the synthetic version, the pre-testing on the target population, the definition of the final version and a second pre-testing on the target population.

RESULTS: A high level of semantic equivalence between the original instrument and the two pairs of translations and back-translations was observed regarding the referential and general meanings. The two pre-testing in the target population led to alterations in order to achieve the criteria of semantic and operational equivalence.

CONCLUSION: This work provides the first adaptation of a specific instrument to detect and quantify dissociative symptoms in the Brazilian context.

Keywords: Dissociative disorders; Questionnaires; Translating

Introduction

The end of the '80s was marked by the renewed interest in the theoretical and clinical studies on dissociative phenomena, especially regarding their relationship with traumatic experiences.^1-3 Recently, the interest in dissociative manifestations has increased with the creation of the acute stress diagnosis by the DSM-IV,⁴ which emphasizes the occurrence of these symptoms. In the Brazilian context, as far as we know, there are no available specific instruments for the detection and quantification of dissociative symptoms, neither developed in Portuguese nor adapted from other languages.

This study presents the stages of translation and adaptation into Portuguese of the Dissociative Experiences Scale (DES)^,5-6 the worldwide most used questionnaire for the screening and quantification of dissociative symptoms. Although the scale should not be used as a diagnostic instrument, the score 30 is considered as the cut-off point above which patients with dissociative symptoms can be identified^.5 In a study by the authors of the DES, 74% of patients with dissociative identity disorder (DID) and 80% of those with other dissociative disorder were correctly identified by this cut-off point.⁵ In this study, 63% of the patients who had a cut-off point above 30 and had not DID showed other dissociative disorder or post-traumatic stress disorder.

DES, therefore, can be used as an instrument to generate cases suspicious of having dissociative disorders. It has been already applied in more than 100 studies⁶ and translated into 17 languages up to now (Sidran Institute, 2003). One validation using metanalysis has found high rates of convergent validity^,6 showing a strong correlation of the DES with other questionnaires for dissociation and also with structured interviews for dissociative disorders, overall the SCID-D⁷ and the DDIS.⁸ Besides, the values of predictive validity, internal consistency and test-retest reliability were also satisfactory.⁶

Methods

The process of transcultural equivalence based on the script developed by Herdman et al,⁹ which has been recently employed in Brazil by Reichenheim et al,¹⁰ and Moraes et al,¹¹ had 7 stages: translation, back-translation, assessment of semantic equivalence, elaboration of the synthetic version, pre-test in the target population, elaboration of the final version and the second pre-test in the target population.

In the first stage, 2 translations of the original English instrument were independently performed by 2 of the authors of this article (M.C., C.L.), both experienced psychiatrists and fluent in English. In the second stage, both translations were back-translated into English, also independently, by two bilingual translators, who were English native speakers.

Stage 3 consisted of the assessment of the semantic equivalence performed by the two other authors (A.F., I.F.), taking into account the referential and general meanings. It was firstly assessed the equivalence between the original instrument and each of the back-translations, considering the referential meaning of words. The referential meaning is related to the ideas and the objects of the world to which one or more words are referred, that is, if one word in the original instrument has the same referential meaning of the corresponding word in the back-translation, their literal correspondence may be affirmed.¹⁰

The second assessment in stage 3 was related to the general meaning of each item of the original instrument and its correspondent in each Portuguese version. The general meaning takes into account not only the literal correspondence between the words, but also more subtle aspects, such as the impact they have in the cultural context of the target population.¹⁰ The divergences between the analyses of equivalence in this stage were the subject of debates, which led the group to the decisions made in the following stage.

In stage 4, a synthetic version has been elaborated. Some items were incorporated from one of the two versions, integrally or modified by the group, whereas the other items stemmed from the combination of the two versions. The result of this combination was sometimes modified to better meet the criteria of semantic equivalence.

Stage 5 involved a pre-test of the synthetic version in a sample of the target population which the questionnaire aims to cover, in order to detect possible incoherencies of meaning between this version and the original instrument. This version was applied to 10 outpatients at the Federal University of Rio de Janeiro - UFRJ, aged 21 to 50 years, being 7 females and 3 males. All patients had coursed elementary school and had diagnostics of anxiety and/or depressive disorders according to the DSM-IV.⁴ In stage 6, the team debated the acceptability of this version in the assessed population, and new modifications have been proposed, resulting in the elaboration of the final version. Stage 7 consisted of the application of the final version in other 10 patients of the same ambulatories, with similar sociodemographic and diagnostic characteristics to those of stage 5 patients.

Results/discussion

The results of stages 1, 2 and 3 are in Table 1, which shows the original instrument, the translations (V1 and V2), performed by 2 of the authors (M.C., C.L.), and their respective back-translations (R1 and R2). In order to assess the referential meaning (stage 3), the two other authors (A.F., I.F.) continuously judged the equivalence between the pairs of items of the original instrument and of the back-translations, with scores ranging between 0% and 100% (A1). These authors also assessed the general meaning (stage 3) through the comparison between the pairs of items of the original instrument and those of the back-translations using a 4-level qualification: unaltered, slightly altered, very altered and totally altered (A2).

Table 1 shows that the two back-translations (R1 and R2) had a high degree of equivalence of referential significance. None of their items showed a percentage of equivalence lower than 85%. Ninety percent of items of R1 and 73% of items of R2 achieved 100% of equivalence of referential meaning. The general meaning of the first translation (V1) remained unaltered for 28 items and slightly altered in only 1 item. The second translation (V2) behaved worse than V1, having 22 unaltered items and 7 slightly-altered items. None of the items of V1 and V2 showed very-altered general meaning.

During the elaboration of the synthetic version (stage 4), some priority was given to V1 in the decision-making process, as 14 items of V1 were chosen against 9 items of V2. In 6 situations, it was decided to combine the content of both translations, and this combination was modified in 2 items. Stage 5 revealed a difficult understanding of the synthetic version by the target population, what led to several modifications in stage 6.

Finally, it was detected a difficulty in the understanding of the instructions of the synthetic version, in which, as well in the original questionnaire, subjects were instructed to show at which percentage the situation asked in the question occurs in their daily life, circling a number between 0% and 100%. Due to the difficulty of most respondents to understand the concept of percentage, we have chosen to modify the answering system.

The version of the DES developed for adolescents contains an answering method which renders unnecessary the concept of percentage.¹² This method guides subjects to circulate one number from '0' to '10' in order to show at which point the situation of the question applies to their daily life. It was chosen to incorporate this answering system to the instructions of the final version.

This change has not affected the way of obtaining the questionnaire's score. In the original version, the score is obtained adding the answers of each of the 28 items, dividing the result by their total number. In this version, it suffices to proceed in the same way, although multiplying the final result by 10, as, in this case, answers varied from 0 and 10, and not from 0 and 100. Besides, the final version has respected the instrument's original format.

In this way, we managed to meet not only criteria of semantic equivalence, but also those of operational equivalence. The latter refers to the possibility that the necessary changes in elements such as format, form of administration and instructions, remain similar to those of the original instrument, not affecting the final result.⁹ The final version of the transcultural adaptation of the DES into Portuguese which was proposed in this study is presented in the appendix.

Conclusion

This study provides the first adaptation into the Brazilian context of a specific instrument to detect and quantify dissociative symptoms. Based on a script provided within an epidemiological survey,^10-11 the 7 stages of the transcultural adaptation of the Dissociative Experiences Scale achieved its objective of meeting criteria of semantic and operational equivalence.

The process of transcultural adaptation of this study was similar to those used by the translators of the DES into other languages, especially those who also employed back-translating techniques: Mandarin, Canadian French, Italian, Japanese, Polish, Spanish, Finish and Ukrainian (Sidran Institute, 2003). It should be highlighted that, despite the fact that the DES has been translated into 17 languages, only the Dutch, Spanish, French, German and Finish versions were submitted to validation studies.^13-16 Therefore, the satisfactory results obtained in this study should be reviewed based on future psychometric assessments.

Acknowledgements

The authors thank to Dr Liliane Vilete for the scientific consulting and to professors Kelly Hayes and Beijamin Lessing for the translation.

Dissociative Experience Scale

DIRECTIONS

This questionnaire consists of twenty-eight questions about experiences that you may have in your daily life. We are interested in how often you have these experiences. It is important, however, that your answers show how often these experiences happen to you when you are not under the influence of alcohol or drugs.

To answer the questions, please determine to what degree the experience described in the question applies to you and circle the number to show what percentage of the time you have the experience.

EXAMPLE:

1. Some people have the experience of driving or riding in a car or bus or subway and suddenly realizing that they don't remeber what has happened during all or part of the trip. Circle a number to show what percentage of the time this happens to you.

2. Some people find that sometimes they are listening to someone talk and they suddenly realize that they did not hear part or all of whhat was said. Circle a number to show what percentage of the time this happens to you.

3. Some people have the experience of finding themselves in a place and having no idea how they got there. Circle a number to show what percentage of the time this happens to you.

4. Some people have the experience of finding themselves dressed in clothes trat they don't remember putting on. Circle a number to show what percentage of the time this happens to you.

5. Some people have the experience of finding new things among their belongings that they do not remember buying. Circle a number to show what percentage of the time this happens to you.

6. Some people sometimes find that they are approached by people that they do not know who call them by another name or insist that they have met them before. Circle a number to show what percentage of the time this happens to you.

7. Some people sometimes have the experience of feeling as though they are standing next to themselves or watching themselves do something and they actually see themselves as if they were looking at another person. Circle a number to show what percentage of the time this happens to you.

8. Some people are told that they sometimes do not recognize friends or family members. Circle a number to show what percentage of the time this happens to you.

9. Some people find that they have no memory for some important events in their lives (for example, a wedding or graduation). Circle a number to show what percentage of the time this happens to you.

10. Some people have the experience of being accused of lying when thwy do not think that they have lied. Circle a number to show what percentage of the time this happens to you.

11. Some people have the experience of looking in a mirror and not recognizing themselves. Circle a number to show what percentage of the time this happens to you.

12. Some people have the experience of feeling that other people, objects, and the world around them are not real. Circle a number to show what percentage of the time this happens to you.

13. Some people have the experience of feeling that their body does not seem to belong to them. Circle a number to show what percentage of the time this happens to you.

14. Some people have the experience of sometimes remebering a past event so vividly that they feel as if they were reliving that event. Circle a number to show what percentage of the time this happens to you.

15. Some people have the experience of not being sure whether things that they remeber happening really did happen or whether they just dreamed them. Circle a number to show what percentage of the time this happens to you.

16. Some people have the experience of being in a familiar place but findiing it strange an unfamiliar. Circle a number to show what percentage of the time this happens to you.

17. Some people find that when they are wacthing television or a movie they become so absorbed in the story that they are unaware of the other events happening around them. Circle a number to show what percentage of the time this happens to you.

18. Some people find that they become so involved in a fantasy or daydream that it feels as though it were really happening to them. Circle a number to show what percentage of the time this happens to you.

19. Some people find that they sometimes are able to ignore pain. Circle a number to show what percentage of the time this happens to you.

20. Some people find that they sometimes sit staring off into space, thinking of nothing, and are not aware of the passage of time. Circle a number to show what percentage of the time this happens to you.

21. Some people sometimes find that when they are alone they talk out loud to themselves. Circle a number to show what percentage of the time this happens to you.

22. Some people find that in one situation they may act so differently compared with another situation that they feel almost as if they were two different people. Circle a number to show what percentage of the time this happens to you.

23. Some people sometimes find that iin certain situations they are able to do things amazing ease and spontaneity that would usually be difficult for them (for example, sports, work, social situations, etc.). Circle a number to show what percentage of the time this happens to you.

24. Some people sometimes find that they cannot remeber whether they have done something or have just thought about doing that thing (for example, not knowing whether they have just mailed a letter or have just thought about mailing it). Circle a number to show what percentage of the time this happens to you.

25. Some people find evidence that they have done things that they do not remeber doing. Circle a number to show what percentage of the time this happens to you.

26. Some people someetimes find writtions, drawings, or notes among their belongings that they must have done but cannot remeber doing. Circle a number to show what percentage of the time this happens to you.

27. Some people sometimes find that they hear voices inside their head that tell them to do things or comment on things that they are doing. Circle a number to show what percentage of the time this happens to you.

28. Some people sometimes feel as if they are looking at the world through a fog so that people and objects appear far away or unclear. Circle a number to show what percentage of the time this happens to you.

References

Sponsoring and Conflict of Interest: Inexistent

Received in 05/15/2003

Accepted in 10/28/2003

Original version accepted in Portuguese

Departament of Psychiatry and Mental Health of the Medical School of the Federal University of Rio de Janeiro - UFRJ

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Publication Dates

• Publication in this collection
  23 Feb 2005
• Date of issue
  Sept 2004

History

• Accepted
  28 Oct 2003
• Received
  15 May 2003