Journal of Asthma, 44:371–375, 2007Copyright C© 2007 Informa HealthcareISSN: 0277-0903 print / 1532-4303 onlineDOI: 10.1080/02770900701364015

Validation of the Brazilian-Portuguese Version of the EuropeanCommunity Respiratory Health Survey in Asthma Patients

MARCOS RIBEIRO,1,2 LUCIENE ANGELINI,2 PRISCILA GAMES ROBLES-RIBEIRO,2 RAFAEL STELMACH,2 UBIRATAN DEPAULA SANTOS,1 AND MARIO TERRA-FILHO1,∗

1Occupational and Environmental Group, Pulmonary Division, Heart Institute (InCor), University of Sao Paulo Medical School,Sao Paulo, Brazil

2Asthma & Airway Diseases Group, Pulmonary Division, Heart Institute (InCor), University of Sao Paulo Medical School,Sao Paulo, Brazil

Background. The European Community Respiratory Health Survey (ECRHS) questionnaire was planned to answer questions about the distributionof asthma. Our objective was to determine the cultural equivalence of the ECRHS into the Brazilian-Portuguese language. Methods. We translatedthe ECRHS according to international criteria. Results. Small cultural adaptations were necessary. Among the 80 participating patients, the Cronbachindices were higher (0.98–1.00) and the Kappa indices varied from 0.77 to 1.00. Conclusion. The study suggests that the Brazilian version of theECRHS is conceptually equivalent to the original and similarly reliable and may be used in international studies involving Portuguese-speakingrespiratory patients.

Keywords asthma, questionnaires, cross-culture validity, European Community Respiratory Health Survey questionnaire

INTRODUCTION

The European Community Respiratory Health Survey(ECRHS) questionnaire (1) in adults and the InternationalStudy on Asthma and Allergy in Children (ISAAC) (2) mea-sure international variations in asthma prevalence by usingsymptoms questionnaires to define asthma (2). In the ECRHS,as well as in the ISAAC, notable differences in the frequencyof asthma by country have been observed (3).

The use of the same questionnaire and definition suggestthat these differences are real. However, a good replicabilityof the diagnostic tool does not exclude international cross-cultural differences in the subjective recognition and reportof symptoms (4).

These instruments have been developed in English-speaking countries and include several health status measuresfor asthma patients (5, 6). Most of these measures have beenshown to be reproducible valid and responsive (7).

A version of this questionnaire (ECRHS) was first devel-oped in England(1, 7—9) with subsequent versions in othercountries (10). Specifically, the survey is designed to estimatevariation in the prevalence of asthma; asthma-like symptomsand airway responsiveness; to estimate variations in expo-sures to known or suspected risk factors for asthma, and as-sess to what extent these variations explain the variations inthe prevalence of disease; and to estimate differences in theuse of medication for asthma. The ECRHS questionnaire hasbeen translated into many other languages and has been val-idated for use in some languages and cultural backgrounds(9–11).

∗Corresponding author: Prof. Dr. Mario Terra Filho, Servico de Pneu-mologia Av. Dr. Eneias de Carvalho de Aguiar 44, CEP: 5403 000 SaoPaulo, Brasil; E-mail: pnemario@incor.usp.br

Adapting a measure developed in a different language andculture may be more timesaving than developing a new one.But, if adaptation is done by a simple translation, it is un-likely to render an equivalent measure because of the influ-ence of language and culture in health-related issues (12). Itis recommended that these instruments undergo a validationprocess (4).

A correct adaptation requires a broader design that takesinto account not only the linguistic but also the technicaland conceptual aspects involved in measuring health status(13). Clinicians and researchers without a suitable asthmaquestionnaire measure in their own language have 2 choices:(1) to develop a new measure, or (2) to modify a measurepreviously validated in another language, known as a cross-cultural adaptation process.

No Portuguese validation and translation version of theECRHS has yet been developed. The aim of the present studywere to develop a Brazilian-Portuguese linguistic and cul-ture translation and validation of the European CommunityRespiratory Health Survey questionnaire (ECRHS-BR) andverify its psychometric properties (validity, reliability, andreproducibility)

METHODS

A cross-sectional study involving asthmatic patients witha wide range of ages and disease severity was carriedout. The European Community Respiratory Health Survey(ECRHS) questionnaire is a standardized self-administeredairway disease-specific questionnaire developed by Burneyet al. (1). It contains 12 items. It is self-administered, easy tocomplete, and all items are answered as either YES or NO.It includes 3 questions related to social status (not includedin the final scores), and 9 questions about asthma symptomsduring the last 12 months. Each positive response to an item

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is rated as 1, and each negative response as 0. All subjectsgave their written informed consent for baseline spirometryand questionnaire administration, and the local medical ethicscommittee approved the study.

ECRHS was translated into Portuguese (Brazilian lan-guage) and then translated back into English by using themethodology used by Ferrer (14). The processes involvedthe translation of the first version by 2 bilingual profes-sionals who were asked to keep conceptual rather than lin-guistic equivalence. Another 2 bilingual persons comparedthe translation with the original and performed a back-translation into English. These translations was reviewed by acommittee of professionals comprising 3 respirologists whorated the equivalence between the first and second transla-tion and the original version, identified inadequate or am-biguous items, and generated alternative expressions. Thecommittee of professionals and the translators took intoconsideration the results of activities and the differencesbetween the back-translation and the original, discussingeach problematic item until a reconciled final version wasreached.

Because the adaptation of the European Community Res-piratory Health Survey questionnaire for Brazilian culture(ERCHS-BR) aimed to reflect the concerns and the usual lan-guage of the patients rather than those of the professionals,this version was confirmed by a previous pilot study includ-ing 10 randomly selected patients. The patients performed 3tasks: first, the patients read the questionnaire; second, pa-tients were probed about their responses and asked to com-ment on each item of the translated version, encouragingthem to express any difficulty they had understanding theitems; third, they were asked to identify, for those items withalternative expressions, the alternative that best conformedto their language usage. None of the 10 patients reportedany difficulty in understanding or answering the questions.Therefore, the ECRHS-BR was adopted as the final versionof the questionnaire.

Asthmatic patients were selected from among those whohad attended the Outpatient Clinic of the Pulmonary Division,University of Sao Paulo Medical School, Brazil. Patients wereclinically evaluated and then administered the ERCHS-BRquestionnaire. Forced expiratory volume in the first second(FEV1) and forced vital capacity (FVC) were obtained afterthe patient interview. Lung function was measured accordingto ATS/ERS guidelines (15) by using a spirometer (KoKoSpirometer, Ferraris Respiratory; Louisville, CO, USA) withall patients in basal condition.

To be accepted into the study, patients had to meet thefollowing criteria: (1) asthma diagnosis at least 1 year be-fore the interview: established according to the criteria ofGINA guidelines (16); (2) a best FEV1 of less than 80%predicted, and an FEV1/FVC ratio of 0.7 or less in theperiod of diagnosis; (3) clinical stability (that is, at least3 months without acute exacerbation); the exclusion crite-rion being presence of other pulmonary and non-pulmonarydiseases considered incapacitating, severe, or difficult tocontrol.

Questions about smoking, chronic cough, other respiratorysymptoms, and occupational exposures were added, but theresults were not analyzed in this research.

Statistical AnalysisData were analyzed using appropriate software (SPSS no.

10 software program, Chicago, IL, USA). A descriptive sta-tistical analysis was used for demographic and clinical char-acterization of the patients. Data are expressed as median(range) unless otherwise stated.

The internal consistency of the Brazilian version of theECRHS-BR questionnaire was tested by determining theCronbach alpha coefficient (17). A minimum of 0.7 for Cron-bach alpha coefficients, as suggested by Nunnally and Bern-stein (18), was adopted as the reliability coefficient for ques-tion comparisons. Test-retest reliability, which measures theability of the ECRHS-BR to produce agreement scores overa short period of time (i.e., at 2 weeks) were determined byKappa coefficients.

The kappa statistic represents the amount of agreement be-tween two individual reviewers beyond the amount that canbe expected on the basis of coincidence, taking into accountthe proportion of disagreement. The kappa statistic takes val-ues between 0 and 1; a kappa value of 0 indicates no moreagreement than that based on sheer coincidence, and a kappavalue of 1 means that the two reviewers completely agree witheach other. A negative kappa value indicates even worse thanchance agreement. When reviewers completely agree witheach other, the rating of each reviewer is as reliable as the rat-ings of the others, and one reviewer will be sufficient. Percentagreement between rates was calculated. The kappa statisticwas used to report the reproducibility between rates; a kappavalue of 0.5 was considered good and a kappa value greaterthan .75 indicates excellent agreement. Observer 1 and 2 werecompared for intra-rate reliability, and the percent agreementwithin rates was calculated. A weighted kappa statistic wasused for measuring the reproducibility within rates. Since itis difficult to compare the weighted kappa with other kappavalues using arbitrary weights, quadratic weights were used.It should be noted that, when quadratic weights are used tocalculate the kappa value, it is identical to the intra-class cor-relation coefficient (ICC). The ICC was used to calculate theintra-rate reliability.

To combine multiple items into a single scale score, theitems should be internally consistent. This was examined us-ing three indicators of internal consistency: corrected item-total correlations, mean inter-item correlation, and Cronbachalpha coefficient. The reliability of the assessment results canbe increased by taking the average rating of all reviewers incases where there is less than perfect agreement, when kappavalues are lower than 1. The Cronbach alpha coefficient wasused as a measure of the reliability of these average ratings.The value of the Cronbach alpha coefficient can vary between0 and 1, where 0 indicates that the results are completely un-reliable and 1 indicates the perfect reliability of the results.

Corrected item–total correlations indicate the extent towhich each item relates to the construct measured by the totalscore. Correcting the total score by removing the item of in-terest prevents spuriously high values due to item overlap. Arecommended minimum value is 0.40. Inter-item correlationindicates the mutual relation between individual items of arating scale. The internal consistency of a group of items canbe evaluated by the Cronbach alpha test, where it is necessaryto know whether these items could result in a measurement

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TABLE 1.—Clinical demographic data from 80 patients with asthma at baselineassessment.

Sex: F/M (n; %) 51 (64)/29 (36)Years of education: 0–8/>8 (n; %) 52 (65) / 28 (35)Age (years): mean – SD – [range] 47.66–14.02 - [19–76]FEV1 (L): mean – SD – [range] 2.03–0.84 - [0.49 –4.60]FEV1% predicted: mean – SD – [range] 72–20 - [25–127]FVC (L): mean – SD – [range] 2.94–1.03 - [1.03–5.75]FVC% predicted: mean – SD – [range] 86–18 - [44–130]FEV1 FVC%: mean – SD – [range] 68–08 - [48–89]FEV1 FVC% predicted: mean – SD – [range] 81–10 - [57–104]

scale. This test indicates the degree of correlation of an itemwith a scale and an item with itself. The lowest value used asreference in clinical studies is 0.7. Any evaluation instrumentmust be reproducible over time, that is, it must reproduce thesame or similar results between two or more applications forthe same patient, provided that his/her clinical status has notchanged.

The methodology used in this study judiciously followsthe methodology already described in the literature, in accor-dance with similar criteria established others authors (4, 14).The methodological norms found in the literature related totranscultural adaptation of research questionnaires should notbe restricted only to translation, but should also include theback-translation, face validation; cultural adaptation and va-lidity (4). The failure to perform any of these stages may leadto errors in the idiomatic, semantic, cultural and conceptualequivalences of the instrument.

To test inter-observer reproducibility, the ECRHS-BR wasapplied 2 times in the same day, by 2 different observers ina random order, with an hour difference. To test intra-patientand intra-observer reproducibility, after a 15-day interval, theECRHS-BR was applied to the same patients, by one of theobservers. A p value of <0.05 was considered statisticallysignificant.

RESULTS

Four words or expressions used in 15 questions (includingitems, response choices, and instructions), 2% of the total,were judged to contain ambiguous words. A group of 10randomly selected stable asthmatic outpatients (5 women;mean ±SD age, 44 ± 18 years; FEV1, 65.1 ± 3.2% predicted;FVC, 79.1 ± 6.3% predicted) confirmed the quality of thetranslation.

Altogether, 80 asthmatic patients (mean ± SD) age,47.66 ± 14.02 years, 51 (64%) women were selected andevaluated prospectively between January and March 2005.The clinical characteristics of these patients are outlined inTable 1.

This questionnaire is self-administered, and the mean timeof ECRHS-BR questionnaire application was 5 minutes. Fourpatients (5%) were illiterate, and, in this case, the question-naire was read in a loud voice by the experimenter. Regard-ing the stage of the disease, 27 (33.5%) were cases of mildasthma, 30 (37.5%) were cases of moderate asthma, and 23(29%) were cases of severe asthma, according to GINA.

The Cronbach α coefficients and Kappa coefficients for 2observers to ECRHS-BR are shown in Table 2. The internalconsistency, as measured by the Cronbach α coefficient, was>0.7 in all the components of the ECRHS-BR.

TABLE 2.—Cronbach α coefficients and Kappa coefficients for each answer ofthe first and second observers in 80 stable patients with asthma.

ERCHS-BR (%) First Second Cronbach Kappa

Q1 Wheeze 90 90 1.00 1.00Q1.1 Wheeze with breathlessness 84 84 1.00 1.00Q1.2 Wheeze without a cold 73 73 1.00 1.00Q2 Waking with tightness in the chest 70 69 0.99 0.99Q3 Waking with breathlessness 71 70 0.99 0.99Q4 Waking with cough 70 57 0.98 0.98Q5 Asthma attack 70 70 1.00 1.00Q6 Treatment for asthma 100 98 1.00 1.00Q7 Rhinitis/Conjunctivitis 80 80 1.00 1.00

Table 3 shows the mean component scores to ECRHS-BRobtained for 80 patients to whom the questionnaire was ad-ministered twice, during the baseline and at 2 weeks. Thescore of ECRHS-BR components were not significantly dif-ferent between the 2 visits (p > 0.05).

The Kappa coefficient was high for all componentsand intra-class correlation coefficient for analysis of intra-observer variability (15-day interval) showed a range from0.77 to 1.00. Evaluated inter-observer analysis of variabilityrevealed, on the same day 1 hour later, a range from 0.98 to1.00; all of these correlations were considered excellent.

DISCUSSION

In this study, we found the Brazilian-Portuguese ver-sion of the European Community Respiratory Health Sur-vey (ECRHS-BR) questionnaire to be acceptable and easyto administer to asthmatic patients. The ECRHS-BR had ac-ceptable to high internal consistency and agreement, and thescores were moderately to highly correlated with a rangeof established measures of respiratory disease activity and ahigh level of test-retest reproducibility.

To be useful, the ECRHS-BR should be validated and re-producible. The validity is the ability of an ECRHS-BR tomeasure what it was intended to measure, and this is ex-pressed as sensitivity and specificity. Reproducibility mea-sures the consistency of answers obtained during reapplica-tion, and it is a measure of reliability.

The results presented are consistent with previous reportsof the original ECRHS instrument (1) and suggest that theBrazilian version is conceptually equivalent to the originaland similarly reliable and valid. The ECRHS questionnaire

TABLE 3.—Test–retest reliability (repeatability) of the ECRHS-BR in 80 stablepatients with asthma.

pERCHS-BR Initial Visit 2-wk Cronbach Value∗

Q1 Wheeze 72 (90%) 73 (91%) 0.77 0.0001Q1.1 Wheeze with breathlessness 67 (84%) 63 (79%) 0.86 0.0001Q1.2 Wheeze without a cold 58 (73%) 55 (69%) 0.80 0.0001Q2 Waking with tightness in the 56 (70%) 54 (68%) 0.90 0.0001

chestQ3 Waking with breathlessness 57 (71%) 59 (74%) 0.90 0.0001Q4 Waking with cough 56 (70%) 40 (50%) 0.90 0.0001Q5 Asthma attack 56 (70%) 56 (70%) 0.97 0.0001Q6 Treatment for asthma 80 (100%) 77 (96%) 1.00 0.0001Q7 Rhinitis/Conjunctivitis 64 (80%) 65 (81%) 0.84 0.0001

∗By paired sample t-test.

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has several advantages over previously used questionnaires:responses refer to symptoms, are independent of utilizationof health services, are not restricted to wheezing, and coverthe 12 months before the survey.

The increasing use of health status measures developed inthe United States or the United Kingdom in countries withdifferent languages and cultures has generated more attentionto the principles and methods of adapting instruments (19).

The cross-cultural adaptation of the ECRHS into Por-tuguese followed a systematic method designed to maxi-mize the conceptual equivalence of the adapted version. Thismethod has yielded an instrument that is highly reliable,showing a pattern and level of correlation with clinical in-dicators, and other measures similar to those of the original.

Although the level of correlation or statistical similaritythat should be accepted as evidence of equivalence is difficultto establish, our results suggest the conceptual equivalenceof the Brazilian version.

Results of the present study suggest the feasibility of adapt-ing a specific instrument of asthmatic patients to be used insettings different from that where the instrument was orig-inally developed. This should facilitate the use of patient-based outcomes in the evaluation of respiratory patients indifferent countries, including the possibility of comparingpatients.

To evaluate the reproducibility of the self-applicableECRHS-BR questionnaire, the interval of time between the 2responses should be long enough so that the individuals haveforgotten their answers, but not so long that the symptomshave changed. For these patients, the concordance indexeswere approximately 80–100%.

Although there is an increasing availability of question-naires to assess patients with asthma, only a few ques-tionnaires have been translated and validated for use withBrazilian patients [e.g., Cystic Fibrosis Quality-of-Life (20);Airways Questionnaire 20 (21); Brazilian ISAAC (22);Saint George’s Respiratory Questionnaire (23); a simplifiedQuality-Of-Life Questionnaire for asthma (24)].

The great advantage of the ECRHS-BR questionnaire is theshorter time of application with maintenance of measurementproperties. For a new test or instrument to be considered ap-propriate for the scientific community, the item usually eval-uated is reproducibility and its correlation to measurementstraditionally used (25).

During the study of reproducibility intra- and inter-observed, the intra-class correlation (17) was calculated, andan excellent concordance was observed when the applicationwas made by the same person or by different experimenters.There was a good intra-class correlation for the ECRHS-BRobtained by 2 observers. This was well above the minimalintra-class correlation coefficient value of >0.70 acceptedfor the demonstration of the reproducibility of a question-naire (25). All correlation coefficients found in this studywere ≥0.90.

In the individual analysis of the answers on different days,a statistically significant concordance was observed rangingfrom 80–100% of the ECRHS-BR questions (Kappa confi-dence correlation).

For 4 responding patients (5%), the questionnaire wereadministered by an interviewer because of the patients in-ability to read or write, despite use of large type in the

printed questionnaire, following the recommendations ofKurtin et al. (26).

The validation of the questionnaire, in Portuguese and inspecific pulmonary disease clinical practice, confirms strongdiscriminative properties, test-retest reliability, and respon-siveness. Overall, results suggest that the ECRHS-BR maybe used in Brazil and in international studies involvingPortuguese-speaking respiratory patients.

Conflict of Interest StatementMarcos Ribeiro – no financial or other potential conflicts of

interest exist; Luciene Angelini – no financial or other poten-tial conflicts of interest exist; Priscila Games Robles-Ribeiro– no financial or other conflicts of interest exist; Rafael Stel-mach – Ubiratan de Paula Santos – no financial or other poten-tial conflicts of interest exist; Mario Terra-Filho – no financialor other potential conflicts of interest exist.

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