We conducted an exploratory studybetween August 2018 and April 2020involving translation, cross-cultural adaptation, andevaluation ofpsychometric propertiesof the Cystic Fibrosis stigma scale.The study was approved by theresearch ethics committee of the Federal University of Rio Grande do Norte (CAAE:96606918.3.0000.5537). We adopted ethical principles established in the Declaration of Helsinki and Resolution 466/12 of the National Health Council.
Participantswere individuals with CF, parents and/or guardians, and experts (pulmonologists, psychologists, and respiratory physiotherapists). They were informed about objectives, risks, benefits, and procedures of the appliedmethodology. We also provided information about non-obligation to participate in the study,anonymity of recorded data, andpossibility ofdropping thestudy at any phase.Linguistic validation required translators and experts in the field (judges during consensusphase). All participants voluntarily signed the informed consent form before participation and data collection.
Linguistic validation protocol: translation and cross-cultural adaptation
Qualitative phase
We requested authorization and cooperationfromoriginal authors of CF stigma scale to developand culturally adapt the scaletoBrazilian Portuguese.Dr. Smita Pakhale gave permission, agreed withthe study, and assistedin the necessary phases.
Methodological approach was based on steps proposed by Guillemin et al. 12 and Beaton et al.13and followed recommendations of COSMIN andMapi Research Institute14: a) translation, b) synthesis of translation, c) backtranslation and synthesis of backtranslation, d) review by experts committee usingDelphi method,and e) pre-test.15-17The two final phaseswere evaluated usingkappa coefficient(>0.6),according to indexes proposed by Landis and Koch.18
Adjustments were performed during translation and cross-cultural adaptation to avoidmisunderstanding due to literal translation of specificwords. Resulting documents were sent to the original author to ensure accordance with the original questionnaire. The expertcommittee was formed by two pulmonologists, two psychologists, two respiratory physiotherapists, one personwhose mother lives with CF, andone individual with CFaged over 18 years; totaling eight participants. Pairs of pulmonologists, psychologists, and respiratory physiotherapists were trained, considering that only one had direct contact with individuals with CF.
Changes in CF Stigma Scale were performed on item 4. The literal translation of the term “bad”to Portuguese is“ruim”, and we decided to change to “má” to maintain sense of the sentence. In item 5, the literal translation of the term “disgusting” to Portuguese is“repugnante”,which is not widely used in colloquial Portugueseandcould modify the original meaning of the phrase. For this reason, we consensually changed to “desagradável”.Additionalterms underwent slight changes aiming a better understanding by Brazilian individuals with CF. After analysis by the expert committee, kappa coefficientshowed values above 0.61, indicating substantial agreement.
Thirty individuals aged between 18 and 42 years were recruited (22 females) in the pre-test.Educational level ranged fromprimary education topost-graduation. Clarity and understanding of items evaluated by kappa showed an interval between 0.48 and 0.72, indicating moderate to substantial agreement.19Last, the Brazilian version of the questionnaire was sent to authors of theoriginal study and expertscommittee for final approval.
Quantitative phase
Psychometric properties were evaluated with Brazilian individuals with CF,using the methodological design of the study by Pakhale et al.11, after cross-cultural adaptation to Brazilian Portuguese.The scale was applied online.A non-probabilistic sampling of Brazilian individuals with clinical diagnosis of CF (confirmed by sweat test) was used because no specific sample calculation exists for methodological validation studies. Since Landis et al.18 recommend five to ten participants for each item to validate a questionnaire, 50 individuals were included (i.e., CF stigma scale has 10 items). Individuals unable to perform or understand procedures and those who underwent lung transplantation were not included.
Recruitment and Questionnaires
Recruitment occurredvia social networks of a Brazilian non-governmental organization (Instituto Unidos pela Vida).Inclusion criteria were presented,and interested individuals were informed to contact researchers for further details. After potential clarifications, a GoogleForms platform® link containing the following information was sent to interested individuals: informed consent form, information on personal data and socioeconomic profile, and four questionnaires (short form of the SF-36v2 Health Survey [SF 12v2], General Anxiety Disorder [GAD-7], Cystic Fibrosis Quality of Life Questionnaire [CFQ], and translated version of CF Stigma Scale). After a three-week interval, the same questionnaires were reapplied online.
SF12v2 is a self-reported scale that assesses general quality of life. It is a short version of SF-36 scale,adapted to reduce time spent during assessment without impairing quality of evaluation. It consists of 12 items thatanalyze physical and mental health statusof individuals based on previous four weeks. Each item is scored on a five-point scale ranging from ‘’all of the time’’ to ‘’none of the time’’ in some cases and from “excellent” to “poor” in others. A cut-off of 50indicates good quality of life.20
GAD-7 is a seven-item self-reported questionnaire used to assess anxiety symptomsbased on previous two weeks. Each item addresses a symptom of anxiety and is scored on a four-point scale (0 = not at all, 1 = on some days, 2 = most days, and 3 = nearly every day). Total score ranges from 0 to 21;higher scores indicatemore severesymptoms of anxiety. GAD-7 was translated and validated for Brazilian Portuguese byMoreno et al., 2016.21
CFQ is a self-reporteddisease-specific questionnaire indicated to individuals aged 14 years or older. It consists of 50 questions covering the following domains: physical, body image, digestive, respiratory, emotion, social, eating, treatment burden, vitality, health perceptions, role, and weight.22Each domain score ranges from 0 to 100, and a cut-off of 50 points indicates good quality of life. CFQ was translated and validated for Brazilian Portuguese by Rozov et al.23
Statistical Analysis
Data was organizedin an Excel spreadsheet andanalyzed using theStatistical Package for Social Sciences software (SPSS®, version 26).Data werepresented as mean and standard deviation,and a 5% significance level was assigned for all analyses. We evaluated content validity, test-retest reliability, and convergent validity. Two types of reliability were assessed in total score and subscales of CF stigma scale: i) internal consistency, using Cronbach’s alpha; and ii) test-retest reliability, calculated using Pearson’s correlation between scores at baseline and after three weeks. Convergent validity was evaluated by comparing means of questionnaire scores usingpaired t-test.