Keywords
Parkinson disease - diagnostic techniques - neurology - deep brain stimulation - validation study
Palavras-chave
doença de Parkinson - técnicas de diagnóstico - neurologia - estimulação cerebral profunda - estudo de validação
Introduction
Parkinson's disease (PD) is a neurodegenerative, progressive, and the most frequent pathology of the movement disorders. Its development occurs in the 55-to-65 years age group, affecting 1 to 2% of the population over 60 years.[1] The prevalence corresponds to ∼ 100 to 150 cases per 100 thousand inhabitants, and the incidence is ∼100 to 200 new cases per 100 thousand inhabitants.[2] Symptoms such as resting tremor seen in one or both hands, less observed in chin, lips, tongue, and feet, bradykinesia, stiffness, and postural instability are part of the syndromic picture. Parkinson's disease requires an early diagnosis and treatment, because of its degenerative character.[3] Therefore, it is important to note that chronic diseases are best managed by specialists, due to the possible unusual presentations and specific therapy.[4]
There are several drug therapies for PD, with the most frequent and effective choice being levodopa, which is, generally, well tolerated by patients. When the patient develops any medication-related complications or even has a decrease in its effectiveness due to the evolution of the disease, its clinical management can represent a challenge.[5]
[6] For these cases, the surgical treatment known as deep brain stimulation (DBS) has been increasingly recommended, as it is a safe and effective treatment for some patients with refractory PD[7]. Another type of minimally invasive surgery for these cases is brain radiofrequency ablation, which consists of the precise and localized application of radiation in a targeted area of the brain affected in PD, usually administered in a single dose. This procedure destroys tissue that produces abnormal chemical or electrical impulses that cause tremors and other symptoms of PD.[8]
[9] A lesion of the globus pallidus, called pallidotomy, is the most common ablative surgery for PD. Deep brain stimulation emerged in a context of greater pathophysiological knowledge and development of stereotaxic methods and electrical neurostimulation. The surgical technique consists of placing one or more electrodes that are connected to an electrical pulse generator device to modulate neural signaling within a specific region. In PD, the target regions are usually the subthalamic nucleus and the globus pallidus internus, areas that are affected in the disease pathophysiology.[7]
[10]
[11]
[12]
There is no consensus in the literature about the best time to submit the patient to surgical treatment. Deep brain stimulation is the standard of care. This predilection is due to reversibility of the method, as well as the possibility of outpatient adjustment and few side effects; Nonetheless, there are few studies comparing the ablative techniques to this procedure.[11]
[12]
[13] Several forms of evaluation of these patients are being elaborated; however, its use is restricted to specialists, which results in a deficit in primary care for these patients.[4] Moro et al. demonstrate in their study that ∼ 63% of patients referred to DBS were not eligible for surgical treatment, highlighting the need to optimize the preselection of candidates for DBS.[14] To make not only the diagnosis more objective, but also the reference and subsequent treatment of patients, the Florida Surgical Questionnaire for Parkinson Disease (FLASQ-PD) was created to elect PD patients for surgical treatment by DBS.[14]
[15]
The FLASQ-PD is a five-section questionnaire: a) criteria for the diagnosis probable idiopathic PD; b) potential contraindications to DBS; c) general characteristics of the patient; d) Favorable/unfavorable characteristics; and e) subscores on the use of medications. The score on this scale points out that higher scores would indicate better candidates for DBS therapy. The best score in the FLASQ-PD is 34 with no alarm signals and the worst result is 0 with 8 alarm signals. When present, the alarm signal automatically indicates that the patient in question presents a high risk of surgical complications.[15]
However, the FLASQ-PD was elaborated based on the North American reality, and like other questionnaires, its translation requires cultural adaptation for application in Brazil. The procedures adopted in this process must be careful, since translation and adaptation are so important for the consolidation of a new instrument in other countries.[16] This adaptation can contribute to the realization of cross-cultural studies that can bring greater clarification and understanding about the frames in study and its specificities in different languagesand cultures.[17] Moreover, it can allow the comparison of different populations and the exchange of information without bias cultural and linguistic barriers.[18]
Faced with the need for objective methods to evaluate the indication for surgical treatment of PD, which facilitates not only the referral of patients to surgical therapy but also the comparison of the Brazilian casuistry with the international one, the present work aimed to carry out the translation and cross-cultural adaptation of the FLASQ-PD.
Materials and Methods
Study Design
A qualitative study of translation and adaptation was performed, with subsequent cultural validation for the Portuguese language. The translation process and cross-cultural adaptation followed the model proposed by Guillemin et al. and Borsa et al.[16]
[19] It consisted of the stages of translation, technical, semantic and conceptual evaluation (committee of experts), evaluation by the target audience (pretests), content validation, back-translation, and final analysis. The study sample was composed of 28 physicians evaluators chosen by convenience, including general practitioners, neurologists, neurosurgeons, and geriatricians. The sample size was calculated according to Guillemin et al..[16]
Translation
In this phase, the purpose was to obtain a version in Portuguese, linguistically correct and equivalent to the original version. Two translators, who are native Portuguese speakers and fluent in English, translated the questionnaire, resulting in two versions in Brazilian Portuguese. Then, reconciliations were made, and the content was analyzed and compressed into the first version in Portuguese with the researchers' participation.
Technical, Semantic, and Conceptual Evaluation (Expert Committee)
The proposed version was subjected to a critical evaluation by a committee of experts, formed by four neurologists/neurosurgeons selected for convenience, who evaluated the items of the instrument in terms of content, technical, linguistic, and semantic aspects of each item, in addition to the adequacy of the instrument. The objective of this phase was to obtain semantic, idiomatic, experiential and conceptual equivalence between the original version and the synthesis of the translations. This assessment was made through individual analysis and, later, collectively through discussions between the members of this experts panel.
Evaluation by the Target Population (pretests)
This stage of the process aimed to verify that the items, instructions, and response scale were understandable to the target audience.[19] Potential users of the questionnaire in question are doctors who deal with PD in their clinical practice, but who are not necessarily subspecialists in movement disorders. The translated and adjusted version by the expert committee was evaluated by geriatricians and/or general neurologists. The analysis was performed through successive pretests in which a dichotomous scale was used, with “C” for understandable items and “NC” for non-understandable items. This process aimed to investigate if the instructions and terms in the items and expressions were, respectively, clear, appropriate, and corresponded to those used in the routine of the clinical practice.[19] The questions with a “non-comprehensible” index higher than 15% were modified, and other pretests were performed until the entire questionnaire reached 100% comprehension.
Content Validation
The evaluation of this phase focused on analyzing the clarity, theoretical relevance and practical relevance of the items and included a new panel of specialists composed of neurosurgeons and neurologists. A 5-point Likert scale was used to judge the criteria by scoring them from 1 to 5, according to which 1 = strongly disagree, 2 = disagree, 3 = neither agree nor disagree, 4 = agree, and 5 = strongly agree; a box of suggestions was also placed for the evaluators if necessary. The items that did not reach 80% agreement between the evaluators (content validation coefficient [CVC] < 0.8) were modified, while the other items were left for the researchers to decide whether to accept the suggestions made.
Back-translation
To identify words that were not clear in Brazilian Portuguese, as well as inconsistencies and conceptual errors, a native English translator performed the back translation. The result was compared with the original questionnaire and the differences found were debated among the researchers to originate the partial Portuguese questionnaire version.
Final Analyses
The instrument was assessed for applicability and understanding, for which the researchers were able to call the committee of experts again and/or request the evaluation of the original author. After discussion, the final version of the adapted translation of the FLASQ-PD into Brazilian Portuguese was obtained.
Results
Participants
Of the 28 participants, among generalists, general neurologists, geriatricians, and neurosurgeons, 6 were eliminated for not responding to the instrument as instructed by the researchers. Thus, 22 physicians made up the final sample (14 professionals participated in the pretest, 4 were part of the expert panel A, and 4 were part of the expert panel B). The average time for reading and evaluating the questionnaire was 30 minutes. Most participants were female (59.09%). The group included professionals from the North, Northeast, and Southeast of Brazil.
Cross-cultural Translation and Adaptation
The two translations performed were synthesized in a single initial version by the researchers. This questionnaire was evaluated by the expert committee regarding technical aspects, content, language, and semantics. The composition of the expert panel A was three neurologists and a neurosurgeon, all subspecialists in movement disorders.
There was disagreement in 10 points of the questionnaire, the suggested changes included approximation of the language to the terms used in Brazilian medical practice, as well as replacement of words translated by others with a meaning equivalent to the original word and the withdrawal of drugs that are not used in Brazil. Nine suggestions given by the evaluators were accepted ([Table 1]), two modifications could not be made as that would alter the structure of the original questionnaire, which is outside the scope of this work.
Table 1
Results after evaluation by the expert committee
|
Original version
|
First translation
|
Modified version
|
|
“excellent response (70–100%) to levodopa”
|
“resposta excelente (70–100%) à levodopa”
|
“resposta excelente à levodopa”
|
|
“memory difficulties or frontal deficits”
|
“queixas de memória ou déficits cognitivos frontais”
|
“queixas de memória ou disfunções frontais”
|
|
“severe depression with vegetative symptoms”
|
“depressão grave com sintomas vegetativos”
|
“depressão grave com sintomas de somatização”
|
|
“trial of Sinemet* (carbidopa/levodopa or Madopar** or equivalent)
|
“teste terapêutico com Sinemet (carbidopa/levodopa ou levodopa + benserazida ou equivalente)”
|
“já fez uso de Carbidopa/Levodopa ou levodopa +b enserazida?”
|
|
“trial of dopamine agonist”
|
“teste terapêutico com agonista dopaminérgico”
|
“já fez uso de agonista dopaminérgico? (exceto os agonistas de liberação prolongada)”
|
|
“trial of either tolcapone or entacapone”
|
“teste com tolcapona ou entacapona”
|
“já fez uso de entacapona?”
|
|
“trial of a combination of Sinemet or equivalent with a dopamine agonist”
|
“teste terapêutico de combinação de Sinemet ou equivalente com agonista dopaminérgico”
|
“teste de carbidopa/levodopa ou levodopa + benserazida ou equivalente com agonista dopaminérgico”
|
Notes: *Sinemet is manufactured by Merck Sharp & Dohme, New York, NY, USA. **Madopar is manufactured by Roche Holding AG, Basel, Switzerland.
Evaluation by the Target Population (pretests)
The first pretest was performed by a group of seven neurologists without subspecialty and geriatricians, numbered from 1 to 7. There were disagreements on nine questions and five answer items. Most of the suggestions concerned the use of clearer synonyms, to make the language more accessible and objective. Four questions and 2 response items were modified, corresponding to the disagreeing items by more than 15% of the group (1.05 of the evaluators). ([Table 2])
Table 2
Results after pre-tests
|
Original version
|
Postcommittee version of experts
|
Modified version
|
|
“…meets the UK Brain Bank Criteria”
|
“…preenche os critérios clínicos da 'UK Brain Bank'”
|
“…preenche os critérios clínicos do 'UK Brain Bank'”
|
|
“Postural instability not caused by primary visual, vestibular, cerebellar, proprioceptive dysfunction”
|
“Instabilidade postural que não seja justificada por déficit visual, disfunção vestibular, cerebelar ou proprioceptiva”
|
“Instabilidade postural que não seja justificada por déficit visual, vestibular, cerebelar ou proprioceptivo primário.”
|
|
“On-off fluctuations (medications wear off, fluctuate with dyskinesia and akinesia)?”
|
“Flutuações “on-off” (diminuição do efeito das medicações, flutuações com discinesia e acinesia)?”
|
“Flutuações “on-off” (diminuição do efeito da medicação antes do horário da próxima dose)?”
|
|
“Gait freezing”
|
“'Freezing' da marcha”
|
“Congelamento da marcha”
|
|
“Swallowing function”
|
“Disfagia”
|
“Deglutição”
|
|
“severe depression with vegetative symptoms”
|
“depressão grave com sintomas de somatização”
|
“depressão grave com sintomas somáticos”
|
|
“Trial of dopamine agonist”
|
“já fez uso de agonista dopaminérgico? (exceto os agonistas de liberação prolongada)”
|
“já fez uso de agonista dopaminérgico? (exceto os agonistas de liberação prolongada). Ex.: pramipexol, ropinirol.
|
|
“Trial of a combination of Sinemet or equivalent with a dopamine agonist”
|
“Já fez uso da combinação de carbidopa/levodopa ou levodopa + benserazida ou equivalente com agonista dopaminérgico?”
|
“Já fez uso da combinação de carbidopa + levodopa ou levodopa + benserazida ou equivalente com agonista dopaminérgico?”
|
The second pretest counted with the participation of a new group formed by 7 doctors, all neurologists without subspecialty, numbered from 8 to 14. There was disagreement in 2 questions and 10 answer items for the evaluators. The suggested changes included corrections of concordance, symbols, and exchanges for synonyms. Suggestions of nominal agreement and uniformity in the writing of symbols were accepted by the researchers, but there were no major changes, since none of the items and questions reached 15% of the total number of evaluators. Thus, the pretest step was completed, giving rise to a new version of FLASQ-PD.
Content Validation
This phase was performed by a new panel of specialists (B), formed by three neurosurgeons and a neurologist, who sought to analyze the clarity, theoretical relevance, and practical relevance of the items. All items were relevant to represent the domain they intended to measure, that is, there was an agreement between the evaluators of 80% or more for all items ([Table 3]). Thus, the researchers chose not to modify the questionnaire after this analysis.
Table 3
Content validation coefficient
|
Content validation coefficient
|
Number of questions
|
|
|
|
Perspicuity
|
Pertinence
|
Theoretical relevance
|
|
0.91–1.0
|
22
|
24
|
25
|
|
0.8–0.9
|
7
|
5
|
4
|
|
< 0.8
|
0
|
0
|
0
|
Back translation
The back-translation of the study version of the FLASQ-PD was performed and compared with the original instrument. With the equality of languages, no discrepancies were seen between the modified terms and the equivalence of meaning was maintained in every questionnaire.
Final Analysis
Ather evaluation and analysis by the members of the expert committee (panel of experts A) about the terms used, questions applicability, and facility use of the scale, the translated instrument was judged as applicable and coherent, considering that it will be used, mostly, by neurologists and geriatricians.
Discussion
The adaptation of a foreign scale can bring advantages beyond its purpose, such as providing a standard measure for application in different cultural contexts, which makes it possible to compare the same phenomenon in different cultures.[20]
The instruments need to present two requirements: reliability and validity to be able to reproduce true and equivalent results in different realities.[21] Cross-cultural adaptation is the first step in the validation process that guarantees such principles. Borsa et al. and Sardinha et al. report that it is not only about literal translation, but also about a meticulous evaluation, considering the cultural aspects, beliefs, behaviors, and specific contexts.[19]
[22] Pilz et al. describe the even greater difficulty that Brazil presents in this regard, since it has continental dimensions with different regionalisms.[23] For this reason, the present study counted on a panel of specialists formed by doctors from different regions and Brazilian states, with different and regional clinical practices, for the instrument evaluation and adaptation.
Sardinha et al. highlight the importance of having two people to carry out the translation, so that the two versions could be compared and discussed to elaborate the synthesized version.[22] This was seen in the present study, where the discussion between translators and researchers raised discrepancies that could be corrected. In the same work, the translators were not laymen in the topic addressed. However, this fact did not generate differences in the results at this stage.[22]
The evaluation by the expert committee allowed grammatical and vocabulary disagreements to be corrected, as well as words to be exchanged or inserted according to what is recommended in Brazilian medical practice. The pretests performed by the target population, on the other hand, detected errors and assessed the understanding of the items. Gasparino and Guirardello showed that the changes made at this stage of the process guarantee clarity and understanding for the target audience. In this phase, other grammatical corrections were accepted for a better instrument understanding.[24] The content validation constitutes the third stage of items analysis, and the instrument proved to be relevant to its purpose. All items were considered validated regarding their content, since they exceeded the standard of at least 80%, according to the methodology. Thus, there were no changes to the questionnaire at this stage due to the high CVC values obtained. Such a fact may be the result of the steps preceding this or the large number of items in the instrument, sufficient to reduce sampling error, however not excessive to the point of causing exhaustion among the evaluators, as was also described by Santos et al.[21]
The translation and cross-cultural adaptation of the FLASQ-PD into Brazilian Portuguese met the requirements of similar previous works, showing acceptability, relevance, and adequacy in all its items.[20]
[25]
[26] As for the item's clarity and comprehensibility, this work showed that with a validation process, it is possible to provide an instrument capable of evaluating PD patients, to choose them according to defined criteria for surgical treatment with DBS, and also to predict more accurately which patients will have a better postsurgical prognosis.
Conclusion
The present study created a Brazilian Portuguese version of the FLASQ-PD instrument that has cross-cultural similarity when compared with the original questionnaire in English. This version can be adopted in research works or even included in medical practice, filling the gap in this work field.
