Cross-cultural adaptation and validation of the Condom Self-Efficacy Scale: application to Brazilian adolescents and young adults 1

ABSTRACT Objective: translate and adapt the Condom Self-Efficacy Scale to Portuguese in the Brazilian context. The scale originated in the United States and measures self-efficacy in condom use. Method: methodological study in two phases: translation, cross-cultural adaptation and verification of psychometric properties. The translation and adaptation process involved four translators, one mediator of the synthesis and five health professionals. The content validity was verified using the Content Validation Index, based on 22 experts’ judgments. Forty subjects participated in the pretest, who contributed to the understanding of the scale items. The scale was applied to 209 students between 13 and 26 years of age from a school affiliated with the state-owned educational network. The reliability was analyzed by means of Cronbach’s alpha. Results: the Portuguese version of the scale obtained a Cronbach’s alpha coefficient of 0.85 and the total mean score was 68.1 points. A statistically significant relation was found between the total scale and the variables not having children (p= 0.038), condom use (p= 0.008) and condom use with fixed partner (p=0.036). Conclusion: the Brazilian version of the Condom Self-Efficacy Scale is a valid and reliable tool to verify the self-efficacy in condom use among adolescents and young adults.


Introduction
The condom is a contraceptive barrier method that grants double protection, as it prevents pregnancy and sexually transmitted diseases (STDs). Therefore, it needs to be used consistently, that is, in all sexual relationships and correctly.
The inconsistent use of condoms among adolescents and young adults has been discussed in the literature and can be observed in different countries. In the Northwest of Cameroon, for example, the rate of volatile condom use among 414 interviewees was considered high (62%) (1) . In Brazil, according to data from the National School Health Survey, one in every four adolescents who started sexual life did not use a condom (2) .
Thus, the epidemiological data signal the need for sexual and reproductive health promotion strategies directed at adolescents and young adults. In addition, perceiving this population as prone to the non-use of this barrier method and knowing the main factors associated with this susceptibility are fundamental to guide the health professionals' actions.
Self-efficacy associated with condom use is defined as the trust in one's own capacity to practice safe sex in difficult situations (3) . This characteristic should be identified in order to prevent the main vulnerabilities and needs to be stimulated with a view to improving the young people's compliance with condom use, in view of its influence on the use of the method. Selfefficacy influences condom use and can be stimulated among adolescents and young adults in order to increase compliance with the method (4) .
In 1999, a North American nurse from Indiana University, USA developed the Condom Self-Efficacy Scale (CSE) to assess the perceived self-efficacy of condom use among adolescents and young adults.
The CSE is a multifactorial tool that consists of 14 items that measure a set of cognitive and motivational skills, besides social and behavioral variables that reveal the self-efficacy in condom use. The factors analyzed are divided among the following domains: (1) communication skills related to condom use, with five items; (2) skills in consistent condom use with three items and (3) skills in consistent condom use with six items. These are measured on a five-point Likert scale, in which 1 represents very unsure, 2 unsure, 3 somewhat sure, 4 sure and 5 very sure (4) .
In view of the lack of adapted tools in Brazil to assess condom use, the CSE was chosen, as the self-efficacy concept influences the use of the method. In addition, the CSE included adolescents, which was very interesting as investigating this population is very important to support specific nursing interventions for this group.
In that conjuncture, the aim in this study was to translate and adapt the CSE scale to Portuguese in the Brazilian context. A valid and reliable scale can be used in nursing practice and in other studies to assess interventions that improve the self-efficacy of adolescents and young adults to use a condom.

Method
A methodological cross-cultural adaptation study was undertaken, in which the following method was adopted for the scale translation and adaptation process, in five phases, as follows: initial translation (1), consensus version of translations (2), backtranslation (3), review by an expert committee (4) and pretest (5) (5) .

Cross-cultural adaptation procedures
As a prerequisite to start the translation and cross-cultural adaptation process, the author of the idiomatic, experiential and conceptual equivalence.
Items with comprehension problems were modified by words that were better understood, making sure to maintain the meaning of the original items.

Verification of psychometric properties
The criteria analyzed in this phase involved relevance, understanding and clarity, association of the item with the theme addressed, which domain the item refers to, relevance and degree of relevance of the item. After the expert committee had assessed the scale, the Content Validation Index (CVI) was used, which assesses the experts' agreement with the content the scale represents, whose coefficient should be superior to 0.78 when more than six judges engage in the assessment (6) . It is added that, for the CVI, three mathematical equations were developed: mean convent validation index for all items in a scale, proportion of scale items that reached score 3 relevant or 4 highly relevant, by all judges, and content validation of the individual items (7) .
The construct validation of the CSE was done after the application of the scale to the target public based on the factor analysis. The sampling adequacy measure Kaiser-Meyer-Olkin (KMO) was used, as well as Bartlett's sphericity test. Scores superior to 0.5 are recommended as acceptable, and scores of 0.7 or higher are considered good; scores between 0.8 and 0.9 are very good and superior to 0.9 excellent (8) .
In the factor analysis, the relation between the item and the factor is measured based on the factor loadings, which can range from -1.00 to + 1.00. The minimum factor loading should be 0.3, positive or negative, to indicate a relation between the item and the factor determined. In this study, when the factor loading was equal or superior to 0.3 and the item was allocated in the domain in question (9) .
The internal consistency test Cronbach's alpha was chosen to analyze the homogeneity of the CSE, the most common reliability measure. This test measures the onedimensionality of a tool, with acceptable tools ranging from 0.7 to 0.8. Thus, when a tool has several subcomponents (domains), the alpha should be calculated individually for each domain as, theoretically, various constructs exist (10)(11) .

Application of information collection
The construct validation took place at a state-  Eu ou meu (minha) parceiro (a) podemos usar o preservativo após ingerir bebida alcoólica.

CSE-10
I could talk about using condoms with any sexual partner.

CSE-11
I could talk about using a condom if I were unsure of my partner's feelings about condoms.

CSE-12
I could talk about using condoms with a potential sexual partner before we started to hug and kiss.

CSE-13
I could talk a partner into using a condom when we have sexual intercourse.

Construct Validity
The characteristics of the sample showed a slight male majority among the participants, who represented 50.7% of the adolescents and young adults. The predominant sexual option was heterosexual, referred by 89% of the participants. The age ranged between 13 and 26 years, the same age range adopted by the author of the original scale. As for the marital status, 66% had a partner and 9.1% had children.
What condom use with the fixed partner is concerned, 58.5% presented inconsistent use of the method.

Brazilian version (CSE-VB)
The answers to the CSE-VB were analyzed by means of the total scale and domain scores: Communication, consistent use and correct used, as observed in Table 1.

Discussion
In the adaptation process, slight changes were made, such as adding the female sex among the research possibilities, in order to include this sex in the condom use. In item 4, the inclusion of the term "sexual relation" was suggested, which contributed to make the item clearer and more understandable. In addition, replacing the word "potential" by "possible" was suggested in item 12. This change was pertinent, as the term "potential" can refer to a characteristic of the partner, while the word "possible" indicates the possibility that a sexual partner might come up.
In item 11, the linguist suggested replacing the word "feelings" by "opinion". It is highlighted that the linguist's presence was fundamental to correct the verbal tenses, enriching the grammatical context. In for the will to use a condom with one's partner. Thus, empowerment to use the method is essential to argue with one's partner (12)(13) .
The male sex showed greater self-efficacy in terms of consistent condom use. This finding supports the evidence appointed in a study that involved Sousa CSP, Castro RCMB, Pinheiro AKB, Moura ERF, Almeida PC, Aquino PS.
comparing the consistent condom use between men and women, the score for men was 48.1%, against 31.8% for women (14) . This difference according to sex involves cultural aspects, as men are stimulated early to have sexual relations, while women are discouraged. (15) . Therefore, men dominate the use of the method, contributing to the higher percentage, while women are confronted with people's judgments on the capacity to execute certain activities and achieve certain kinds of performance, that is, the practice of condom use predisposes their self-efficacy (16) .
In addition, self-efficacy was also associated with the consistent condom use domain, concerning condom use with one's fixed partner in all or most sexual relations.
During a field study involving 8,471 adolescents from the state of Paraíba, in 31% of the reports, great female difficulty to negotiate on the condom was observed (17) .
This reality was also found in a Brazilian cross-sectional study involving 17,371 secondary school students, in which unsafe sex was found among older girls with low socioeconomic conditions (18) .
It is inferred that adolescents and young adults who use a condom with their fixed partner present high self-efficacy scores. This finding differs from another study in which inconsistent condom use was observed among young people with fixed partners, as many tend to abandon the method as the relationship gains stability (19) .
Having a fixed partner influences correct condom use (p=0.020). Hence, self-efficacy should be encouraged in this population, as difficulties with correct condom use imply the abandonment of the method. A study involving 166 adolescents showed that this population faces difficulties to correctly use the condom. Among the adolescents interviewed, 16.9% indicated difficulty to use the method in their first sexual relation (20) . The difficulties in this face of sexual discovery induce the non-use of the method and the adoption of sexual risk behaviors. In the adapted version for Korea, the alpha coefficient was superior (0.91) (4,(21)(22) . These data indicated the good reliability of the scale in different contexts.
It was noticed that the self-efficacy for condom use can be stimulated among students through educational interventions. The use of valid and reliable tools can help to identify individual vulnerabilities early.

Conclusion
The use of the method described permitted a strict cross-cultural adaptation process of the CSE.
The scale version after the assessment by the first expert committee and the application of the pretest was considered understandable to the target public.
Thus, it can be concluded that the CSE-VB is a valid and reliable tool to measure the self-efficacy for condom use among adolescents and young adults. The Brazilian version of the CSE can be used in nursing practice to assess interventions that improve the selfefficacy for condom use.
It is highlighted that, even after a strict adaptation and validation process, for the use of this scale in other Brazilian regions, a new semantic validation process is necessary due to linguistic variations specific to each region.