European Portuguese Language Research Articles

Evaluation of the Ability to Sing Easily: Adaptation and validation to the European Portuguese language

Purpose: To adapt and validate the Evaluation of the Ability to Sing Easily (EASE) to the European Portuguese language; to compare scores according to singing style, voice use, and demography variables; to conduct psychometric tests. Methods: A five-step approach was adopted to ensure the cross-cultural adaptation of the instrument including forward translation, backward translation, committee opinions, and pilot testing. Results: The pilot test was conducted with ten singers, which determined the reformulation of seven items, thereby, allowing the formulation of the final form. The EASE-PT was completed by 120 singers, age range 18–72 and 58.3% were female. Median results were significantly higher for Choir singers except for one item where the median was significantly higher for Fado singers. High internal consistency was obtained, Cronbach’s alpha > 0.80 for EASE scale for both Fado and Choir singers, and its sub scales were close to or exceeded 0.80. Conclusion: EASE-PT may be considered a reliable tool to apply in the case of Portuguese singers as the outcome supports the ability of EASE-PT to measure the same constructs in a way similar to that of the original version.

Domain Adaptation Speech-to-Text for Low-Resource European Portuguese Using Deep Learning

Automatic speech recognition (ASR), commonly known as speech-to-text, is the process of transcribing audio recordings into text, i.e., transforming speech into the respective sequence of words. This paper presents a deep learning ASR system optimization and evaluation for the European Portuguese language. We present a pipeline composed of several stages for data acquisition, analysis, pre-processing, model creation, and evaluation. A transfer learning approach is proposed considering an English language-optimized model as starting point; a target composed of European Portuguese; and the contribution to the transfer process by a source from a different domain consisting of a multiple-variant Portuguese language dataset, essentially composed of Brazilian Portuguese. A domain adaptation was investigated between European Portuguese and mixed (mostly Brazilian) Portuguese. The proposed optimization evaluation used the NVIDIA NeMo framework implementing the QuartzNet15×5 architecture based on 1D time-channel separable convolutions. Following this transfer learning data-centric approach, the model was optimized, achieving a state-of-the-art word error rate (WER) of 0.0503.

Validation of the European Portuguese Language Version of the Standardized Cosmesis and Health Nasal Outcomes Survey.

The Standardized Cosmesis and Health Nasal Outcomes Survey (SCHNOS) questionnaire is a tool developed to evaluate functional and aesthetic components of rhinoplasty. It is a reliable patient-reported outcome measure, not available in the European Portuguese language. Our goal was to translate and culturally adapt the SCHNOS questionnaire to the European Portuguese language. The questionnaire was forward and backward translated and culturally adapted to the European Portuguese language following international guidelines. The authors evaluated internal consistency, correlation, and reproducibility to determine the validity of the questionnaire. The final European Portuguese version of the SCHNOS was administered to 58 native European Portuguese speakers. Both the SCHNOS-O (obstructive) and SCHNOS-C (cosmetic) showed high internal consistency with Cronbach's α of 0.93 and 0.95, respectively. Also, for the entire SCHNOS, Cronbach's α was 0.96. All the items demonstrated good item-test and item-rest correlations with the differences between pre- and postestimates being nonsignificant. The translation, adaption, and validation of the SCHNOS into European Portuguese were successfully performed. This provides another tool to help evaluate the functional and aesthetic outcomes of rhinoplasty patients.

Portuguese Cross-Cultural Adaptations of the Pediatric International Knee Documentation Committee Score

The aim of this study was to translate the Pediatric International Knee Documentation Committee Score (Pedi-IKDC) into European Portuguese language. The Pedi-IKDC was originally developed in the English language and its main construct is functional assessment of knee disorders in children and adolescents. The original English version of the questionnaire was translated to European Portuguese using the forwardbackwards method. Patients aged eight to 17 with knee disorders were considered eligible for the study. An online platform was implemented to collect patient responses, including general patient information, the questionnaires Pedi-IKDC, EuroQol-5 Dimension Youth and Childhood Health Assessment Questionnaire. Three surveys were sent: at the moment of first evaluation (T0), after two (T1) and ten (T2) weeks. These surveys followed the Consensus-based Standards for the Selection of Health Measurement Instruments - COSMIN Checklist recommendations. The internal consistency, reliability, error of measurement, structural and construct validity (by means of correlation with previously validated scales), responsiveness and interpretability (floor/ceiling effects, MIC and ROC curve) were evaluated. Forty-seven patients completed T0, 42 patients completed T1 and 40 patients completed T2. The factorial analysis confirmed that the scale has one dimension. Cronbach alpha (α) was 0.94; interclass correlation coefficient was 0.92; smallest detectable change was 19.04 for individuals and 3.31 for groups; standard error of measurement was 6.87; minimum important change was 18.48; floor and ceiling effects were absent. More than 75% of the hypotheses tested for construct validity were confirmed, showing its adequacy. The variation of scores between T0 and T2 correlated with the clinical evolution of the participants (r = 0.421, p < 0.05). The Portuguese version of Pedi-IKDC demonstrated good psychometric properties, being a valuable tool for clinical assessment of pediatric patients with knee disorder.

European Portuguese Language and Cultural Validation of the Chronic Obstructive Pulmonary Disease Assessment Test.

The chronic obstructive pulmonary disease assessment test (CAT) is a self-administered questionnaire that measures health-related quality of life. GOLD proposes using this questionnaire, since it provides thorough coverage of the impact of chronic obstructive pulmonary disease (COPD) on well-being. This questionnaire has been widely used in daily clinical practice in Portugal, but it lacks validation for European Portuguese. The aim of this study was to carry out the cultural adaptation and validation of the CAT questionnaire so that the most appropriate version can be made available to Portuguese researchers and clinicians. A cross-sectional descriptive study was performed involving 65 patients with COPD aged 40 years or older. CAT and the previously validated Portuguese-language version of the Clinical Questionnaire for COPD were applied between January 2019 and June 2019. The agreement between the two questionnaires was determined with Kappa agreement with a 95% confidence interval. Spearman correlation was used to find the correlation between two scores. The 65 patients included in the study were observed in a hospital-based pulmonology clinic [aged 68 ± 7 years; forced expiratory volume in 1 sec (FEV1) 49.86% ± 16.5% predicted]. CAT correlated significantly with all the domains and the overall score of the CCQ (0.47 < r < 0.75; p < 0.001). The bilingual patient interclass correlation coefficient was 0.922; Pearson's r = 0.928; p < 0.001. The Cronbach's alpha coefficient was 0.96 (p < 0.001). The European Portuguese version of the COPD Assessment Test is a valid instrument for measurement of health-related quality of life in COPD patients. The use of validated questionnaires is of great importance since it generates reliable and reproducible evidence for use either in research or clinical practice.

Literalization in the self-revision process of novice and experienced biomedical translators

Abstract This paper explores decision-making in translation focusing on the self-revision process of novice and experienced translators of biomedical content in the English to European Portuguese language pair. Adopting process- and product-oriented methods, an experiment was designed to study thirty translations of a 244-word instructional text about a medical device intended for health professionals. The data elicited from fifteen novice translators and fifteen experienced translators included keylogging and screen-recording data. These data were triangulated and analyzed to describe the translation solutions in the interim and final versions in response to problematic translation units and to test if, during the self-revision process, novice and experienced translators tend to proceed from more literal versions to less literal ones, or vice versa, in biomedical translation. Contrary to expectations, the analysis points towards a literalization phenomenon in the translators’ processes. The data also indicates that the tendency to proceed from less literal versions to more literal ones is more pronounced in novice translators than in experienced translators. The findings reported here shed new light on the self-revision processes of novice and experienced translators and their relationship with prevailing translation norms, and enable us to better understand the practices in place in professional biomedical translation.

Portuguese Version of the Intentional Non-Adherence Scale: Validation in a Population of Chronic Pain Patients.

Objective: Despite the effectiveness of pain medicines, nonadherence to prescribed medication remains a major problem faced by healthcare systems. The aim of present study was to perform the translation, cultural adaptation, and validation of the Intentional Non-Adherence Scale (INAS) for the European Portuguese language in a sample of chronic pain patients. Methods: A Portuguese version of the INAS scale was constructed through a process of translation, back translation, and expert’s panel evaluation. A total of 133 chronic pain patients were selected from two chronic pain clinics from tertiary hospitals in Porto, Portugal. The protocol interview included the assessment of pain beliefs (PBPI), beliefs about medicine (BMQ), medication adherence (MARS-P9), and two direct questions about adherence previously validated. Results: The internal consistency in all subscales was α = 0.902 for testing treatment; α = 0.930 for mistrust treatment; α = 0.917 for resisting treatment; and α = 0.889 for resisting illness. Exploratory and confirmatory factor analysis revealed a four-factor structure that explained 74% of the variance. The construct validity of the INAS was shown to be adequate, with the majority of the previously defined hypotheses regarding intercorrelations with other measures confirmed. Conclusion: The Portuguese version of INAS could be a valuable and available instrument for Portuguese researchers and clinicians to assess the intentional nonadherence determinants during the management of chronic pain.

Lexical and semantic variation in contemporary spoken Portuguese in urban Funchal and rural areas of Madeira Island

This paper aims to provide a dialectal and sociolinguistic approach and description of the use of the lexical and semantic regionalisms in contemporary spoken Portuguese in urban Funchal (the capital of Madeira) and in four rural areas of the island. The study of the lexicon and its semantic variation is based on recent samples of a semasiological questionnaire, applied to stratified informants by sex/gender, age group and level of education. The correlation of the results with the extralinguistic factors, geographical origin of the respondents on the island and sociocultural variables from the qualitative analysis and the quantitative point of view confirm that speakers from urban areas are less conservative than those from rural areas and showed flexibility and variability as well as stability of lexical meanings, two opposite and complementary lexicon characteristics. The traditional lexicon of Madeira studied highlights the coexistence of dialectal forms, some of them common to the Azores and Brazil, with European Portuguese standard variants. Therefore, the qualitative and the quantitative expression of the knowledge of Madeiran regionalisms and their lexical and semantic variations expose their vitality and support the heterogeneity of the European Portuguese language and the identity of the Portuguese spoken on Madeira Island.

The Use of the Past Tenses in European Portuguese by Slovene Students: The Causes of Possible Deviations

Abstract The analysis presented in this article aims to ascertain what conditions of use imply deviations in the use of the Past tenses in European Portuguese (PPS, PPC, PI, PMQC) by Slovene learners of Portuguese, A2-B1 level (QECRL), trying to find explanations for its occurrence. The analysis shows the contrast between European Portuguese and Slovenian language in the domain of the Past tenses in terms of tense and aspect, describes the most frequent and evident deviations in a corpus, consisting of the various genres of texts, worksheets, completed by the students. Several presumptions were verified in the qualitative analysis. Among them, the deviations are in most cases due to the fact that in the sphere of the past, the Slovene language is operating with only one paradigm of the past sphere, the preteklik (Past tense), which is supposed to mark all the temporal and aspectual nuances of four Portuguese past tenses of the Indicative. The article tries to underline the different way of marking time and aspect in the respective languages and therefore the students’ difficulties in the perception of temporal and aspectual perfect / imperfect conceptualization.

Verbos copulativos com locativos em Português Europeu e em Língua Gestual Portuguesa

Verbs and their syntactic and semantic properties have been studied in several languages, in different theoretical frameworks. However, as for copulative verbs, studies of Sign Languages are still scarce, mainly of Portuguese Sign Language. Therefore, in this paper, some properties of predicative phrases with adjectives, participles and locatives in European Portuguese and Portuguese Sign Language are studied, comparing them with other Oral Languages, in particular Iberian Romance languages, and also with other Sign Languages. Portuguese Sign Language data seem to indicate that the copulative verb is lexically realized when there is a locative predicate and that with a non-locative predicate a null copula occurs.

Cross-Cultural Adaptation and Psychometric Properties of the European Portuguese Version of the Central Sensitization Inventory in Adolescents With Musculoskeletal Chronic Pain.

Central sensitization (CS) is an important feature in musculoskeletal chronic pain, and associated symptoms can be assessed using the Central Sensitization Inventory (CSI). This study aimed to translate and cross-culturally adapt the CSI to the European Portuguese language and to assess its validity and reliability in adolescents with musculoskeletal chronic pain. The European Portuguese version of the CSI was established following the translation and testing processes recommended by international guidelines. Then, this version of the CSI was completed by 1,730 adolescents, who also completed the Nordic Musculoskeletal Questionnaire; the Pain Catastrophizing Scale; the Depression, Anxiety and Stress Scale; the Tampa Scale of Kinesiophobia; and the Basic Scale on Insomnia Complaints and Quality of Sleep. Test-retest reliability and measurement error, internal consistency, hypothesis testing, and factor analysis were assessed for the translated version of the CSI. Cronbach's alpha was 0.91, the intraclass correlation coefficient was 0.94 (95% confidence interval: 0.90, 0.96), and the standard error of measurement and smallest detectable change were 4.15 and 11.50, respectively. Fair correlations were found between CSI and fear of movement (Spearman's correlation [rs ] =0.46), sleep (rs =0.46), and catastrophizing (rs =0.49). Moderate to good correlations were found between CSI and depression (rs =0.60), anxiety (rs =0.59), and stress (rs =0.65). The European Portuguese version of the CSI was considered easy to understand and showed very good internal consistency, excellent test-retest reliability, and excellent construct validity in a community sample of adolescents with musculoskeletal chronic pain.

European Portuguese version of the functional disability inventory: translation and cultural adaptation, validity, and reliability in adolescents with chronic spinal pain

Background Functional disability affects a large percentage of adolescents with chronic pain. The functional disability inventory (FDI) has been widely described in the literature to assess functional disability, with good psychometric properties. Purpose To translate and adapt the FDI to European Portuguese language and assess the validity, reliability, and measurement error of this version in adolescents with chronic musculoskeletal pain and, specifically, with neck and low back pain. Method The translation and cross-cultural adaptation of the FDI was conducted according to international guidelines. After that, 1730 adolescents completed the following scales and questionnaires: FDI, Nordic Musculoskeletal Questionnaire, Numeric Pain Rating Scale, Pain Catastrophizing Scale, Depression, Anxiety and Stress Scale, Tampa Scale of Kinesiophobia, and Basic Scale on Insomnia complaints and Quality of Sleep. Sixty-three of these adolescents, with at least one painful body site, completed the questionnaire twice to assess reliability and measurement error. Exploratory factor analysis and hypothesis testing was used to assess construct validity. Results Cronbach’s alpha ranged from 0.81 and 0.88, ICC was 0.86 (95%CI:0.77; 0.92), the SEM and the SDC were 2.50 and 6.93 (total score of 60 points), respectively. Fair to moderate correlations were obtained between FDI and pain intensity (r s = 0.33 to 0.43), catastrophizing (r s = 0.41 to 0.44) depression, anxiety, and stress (r s = 0.48 to 0.53), fear of movement (r s = 0.32 to 0.42), and sleep impairments (r s = 0.34 to 0.38). The factor analysis suggested a two-factor solution. Conclusion The European Portuguese version of the FDI has very good internal consistency, good test–retest reliability, and construct validity when used in a sample of community adolescents with chronic pain. Implications for rehabilitation One of the most widely instruments used to assess functional disability is the Functional Disability Inventory (FDI), which in its original version has good psychometric properties and is recommended by the Pediatric Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials; However, the FDI has not been translated yet into European Portuguese language and its psychometric properties have not been assessed in adolescents with chronic spinal pain; This study suggests that the European Portuguese version of the FDI has very good internal consistency, good test–retest reliability as well as construct validity when used in a sample of community adolescents with chronic spinal pain; Therefore, these findings suggest the use of the European Portuguese version of the FDI to assess the functional disability in adolescents with chronic spinal pain.

THE NOTION “LEXICAL BRAZILIANISM” AND ITS INTERPRETATION

European and Brazilian variants of Portuguese differ from one another on different levels, including lexis. Lexical divergences can be either of systemic or of variational nature. One can speak of systemic oppositions when the lexemes in question are not regularly used outside the national variant they belong to. Variational opposition presupposes that the lexemes opposed are used in both variants but their frequency differs considerably. Traditionally, the words that make up the Brazilian pole of systemic oppositions are called “brasileirismos” (“brazilianisms”), which is reflected in lexicographic sources by means of special sigla. However, a considerable number of lexemes that are obviously preferred by Brazilian Portuguese speakers (in contrast to the European Portuguese language community) are not accompanied by the corresponding sigla. This fact makes us believe, firstly, that the notion “brazilianism” in modern Brazilian lexicography is still vague, and, secondly, that lexical oppositions between European and Brazilian Portuguese are of continuous nature, that is, their preferential use in Brazil is rather a tendency than a necessity.

Portuguese version of the Medication Adherence Report Scale (MARS-9): Validation in a population of chronic pain patients.

The aim of present study was to perform the translation, cultural adaptation, and validation of the Medication Adherence Report Scale (MARS-P9) for the European Portuguese language in a sample of chronic pain patients. A Portuguese version of the nine-item MARS (©Professor Rob Horne) scale (MARS-P9) was constructed through a process of translation, back translation, and experts' panel evaluation. A total of 141 chronic pain patients were subsequently evaluated at four time assessments during a 1-year pain medication treatment. The protocol interview included the assessment of pain intensity and interference (BPI), clinical outcomes and quality of life (S-TOPS), and MARS-P9. The internal consistency coefficient was acceptable for the total scale (α=0.84). Exploratory factor analysis revealed a two-factor structure (intentional and unintentional nonadherence) that explained 61% of the variance. Convergent and discriminant validity were demonstrated by correlations between MARS scores and pain interference (r=0.180, P≤0.01) and S-TOPS (r=0.242, P≤0.05). MARS-P9 has been shown to be an adequate instrument for Portuguese researchers and clinicians to assess the pattern of adherence during the management of chronic pain.

Portuguese Version of the Pain Beliefs and Perceptions Inventory: A Multicenter Validation Study.

We aimed to perform the translation, cultural adaptation, and validation of the Pain Beliefs and Perceptions Inventory (PBPI) for the European Portuguese language and chronic pain population. This is a longitudinal multicenter validation study. A Portuguese version of the PBPI (PBPI-P) was created through a process of translation, back translation, and expert panel evaluation. The PBPI-P was administered to a total of 122 patients from 13 chronic pain clinics in Portugal, at baseline and after 7days. Internal consistency and test-retest reliability were assessed by Cronbach's alpha (α) and intraclass correlation coefficient (ICC). Construct (convergent and discriminant) validity was assessed based on a set of previously developed theoretical hypotheses about interrelations between the PBPI-P and other measures. Exploratory and confirmatory factor analyses were performed to test the theoretical structure of the PBPI-P. The internal consistency and test-retest reliability coefficients for each respective subscale were α=0.620 and ICC=0.801 for mystery; α=0.744 and ICC=0.841 for permanence; α=0.778 and ICC=0.791 for constancy; and α=0.764 and ICC=0.881 for self-blame. Exploratory and confirmatory factor analysis revealed a four-factor structure (performance, constancy, self-blame, and mystery) that explained 63% of the variance. The construct validity of the PBPI-P was shown to be adequate, with more than 90% of the previously defined hypotheses regarding interrelations with other measures confirmed. The PBPI-P has been shown to be adequate and to have excellent reliability, internal consistency, and validity. It may contribute to a better pain assessment and is suitable for research and clinical use.

Portuguese cultural adaptation and validation of the Activities Scale for Kids (ASK)

ObjectivesThe main purpose of the current study was to perform the cross cultural adaptation and validation of the Activities Scale for Kids (ASK) both in its capability and performance versions to the European Portuguese language so it can be used in Portugal by healthcare professionals in children from 5 to 15 years of age with functional disabilities related to specific health conditions. MethodsThe cross‐cultural adaptation of ASK followed the classic sequential methodology for linguistic equivalence. To test its validity, internal consistency, and reproducibility, the Portuguese version of ASK was administered together with the KINDL Questionnaire (KINDL) to 88 children (10±3 years of age) with functional limitations. The test–retest study was conducted two weeks apart. ResultsAfter obtaining the semantic and content validity, the Portuguese version of ASK demonstrated good levels of reproducibility (performance: intraclass correlation coefficient [ICC]=0.99; capability: ICC=0.98) and internal consistency (performance: α=0.98; capability: α=0.97). The correlations between ASK and KINDL were positive and moderate. ConclusionsThe Portuguese version of ASK showed acceptable levels of validity, internal consistency, and reproducibility; the authors recommend its use in clinical settings.

Portuguese cultural adaptation and validation of the Activities Scale for Kids (ASK)

ObjectivesThe main purpose of the current study was to perform the cross cultural adaptation and validation of the Activities Scale for Kids (ASK) both in its capability and performance versions to the European Portuguese language so it can be used in Portugal by healthcare professionals in children from 5 to 15 years of age with functional disabilities related to specific health conditions. MethodsThe cross-cultural adaptation of ASK followed the classic sequential methodology for linguistic equivalence. To test its validity, internal consistency, and reproducibility, the Portuguese version of ASK was administered together with the KINDL Questionnaire (KINDL) to 88 children (10±3 years of age) with functional limitations. The test–retest study was conducted two weeks apart. ResultsAfter obtaining the semantic and content validity, the Portuguese version of ASK demonstrated good levels of reproducibility (performance: intraclass correlation coefficient [ICC]=0.99; capability: ICC=0.98) and internal consistency (performance: α=0.98; capability: α=0.97). The correlations between ASK and KINDL were positive and moderate. ConclusionsThe Portuguese version of ASK showed acceptable levels of validity, internal consistency, and reproducibility; the authors recommend its use in clinical settings.

Adaptação e validação para português da HIV Antibody Testing Attitude Scale

Resumo Objetivo Adaptar culturalmente e validar uma versão em Português Europeu da HIV Antibody Testing Attitude Scale. Métodos Estudo referido a investigação metodológica, para adaptação e validação de instrumento de medida atitudinal. Realizou-se a tradução, retrotradução. Seguiu-se pré-teste. Amostra de 317 sujeitos que pertencendo à comunidade académica na qualidade de estudantes e funcionários docentes e não docentes que foram abordados no campus. Foram observados os princípios éticos. Resultados Realizaram-se três ensaios de análise fatorial de componentes principais a cinco, quatro e três fatores. Redundou numa solução a três fatores que que explica 50,82% da variância. Na análise da correlação inter-itens observaram-se valores entre -0,018 e 0,749. A consistência interna revela coeficientes de alfa de Cronbach de 0,860 no global e entre 0,865 e 0,659 nos três fatores. Conclusão A versão do instrumento mostra propriedades psicométricas que permitem a sua aplicação em países lusófonos.

Validação para a população adolescente portuguesa com dor lombar do Modified Hanover Functional Ability Questionnaire

Low back pain is a common symptom in younger populations but the real functional impact of this condition remains underreported. In the absence of culturally adapted and validated instruments to assess the functional impact of low back pain in Portuguese adolescents, a methodological study was developed aiming to translate and culturally adapt the modified version of the Hanover Functional Ability Questionnaire (MHFAQ) to the European Portuguese language and examine its psychometric properties.The MHFAQ was first translated and back translated following the published guidelines. The Portuguese version of the MHFAQ was then piloted in a Portuguese sample of 40 adolescents with low back pain complaints and assessed for reliability through internal consistency and reproducibility, using Cronbach's alpha and intraclass correlation coefficient (ICC2,1), respectively. Construct validity was assessed using Spearman's correlation analysis between the MHFAQ‐PT and the Numeric Pain Rating Scale (NPRS), for convergent validity, and between the MHFAQ‐PT and the Health Mental dimension of the Medical Outcomes Study Short‐Form Health Survey Instrument 12‐Item (SF‐12), for discriminant validity, in a new sample of 127 adolescents. One week test‐retest reliability was 0.973 (CI: 95%: 0.948‐0.986, p <0.01) and Cronbach's alpha was 0.699, indicating good reliability estimates for the Portuguese version of the MHFAQ. The results showed a moderate positive correlation between MHFAQ‐PT and END (rs=0.591, p<0.01), and a negative correlation between MHFAQ‐PT and Mental Health dimension of the SF‐12 (rs=−0.426, p<0.01). Therefore, the translated and adapted version of MHFAQ is acceptable to assess functional status of Portuguese speaking adolescents with low back pain complaints.

Cross-cultural adaptation and validation of the neck disability index to European Portuguese language.

Cross-cultural adaptation and psychometric testing. To complete the cultural adaptation of the European Portuguese version of the neck disability index (NDI-PT) and to investigate its reliability and validity in patients with chronic neck pain (CNP). The NDI is the most widely used instrument for self-reporting of disability due to neck pain. Although the NDI has demonstrated both good reliability and validity, a recent systematic review called attention for the poor methodological quality of the translation processes and psychometric studies. The NDI-PT was first piloted in a sample of 40 patients with CNP. Then, 113 patients with CNP completed the numeric pain rating scale and twice the NPI-PT with an interval of 4 to 7 days. Factor structure of the NDI was explored through principal component factor analysis. The internal consistency was estimated using the Cronbach α coefficient. Reliability was determined by repeatability using intraclass correlation coefficient (2,1) for the total sample and for the subsample of participants who remained stable in CNP status between the initial and follow-up assessment based upon the global rating of change scale, and agreement using the concept of "limits of agreement." Construct validity was assessed with correlations between the NDI-PT and the numeric pain rating scale for convergent validity, using Pearson correlation analysis. Exploratory factor analysis revealed the existence of 1 major factor that explained 54.7% of the variance. Test-retest reliability was 0.9 and internal consistency was 0.95. No systematic trend was observed in the Bland and Altman method. The NDI-PT showed a good correlation with pain intensity (r = 0.525, P < 0.01). The NDI-PT demonstrated excellent reliability and good construct validity and it may be useful for assessing functional status of Portuguese-speaking patients with CNP.