Response to “Factors Associated With Self-Efficacy for Condom Use and Sexual Negotiation Among South African Youth”

Abstract

To the Editor: In their article, Sayles and colleagues1 addressed meaningful information on “Factors Associated With Self-Efficacy for Condom Use and Sexual Negotiation Among South African Youth”. South Africa is one of the most affected countries in the AIDS epidemic. The authors adopted a self-cognitive model to identify variables that could enable elucidation of the pattern of self-efficacy for condom use and sexual negotiation. They ignore the variables in the model in the multiple logistic regression, however. The modeling was based on adjustment for sociodemographic confounding factors and was performed as if the variables in the domains were not affected by those on other domains. We would expect a conceptual model to discuss the relation among variables2 and take them into the multivariate analysis. Regarding the self-efficacy for condom use and sexual negotiation, the authors used a 5-item scale, constructed in part from a previously validated 14-item scale of condom use self-efficacy, which had a 0.85 Cronbach α coefficient.3 Nevertheless, no information was given about the validation process of the short scale. Considering the substantial decline of the Cronbach coefficient of the new scale, 0.64 for women and 0.60 for men, we anticipate that said scales have different constructs. Because α values higher than 0.7 are required for satisfactory comparisons between groups,4 this paper has a relevant drawback that the authors failed to address in the discussion. The use of a nonvalidated scale and the lack of adjustments for other confounding factors might explain why some known associations were not confirmed in this study. For instance, the authors did not find an association between HIV infection and the first sexual experience before 15 years of age, contrary to other studies5,6 and our own findings.7 Paulo Ricardo de Alencastro, MD*† Nêmora Tregnago Barcellos, PhD*† Helena Barreto dos Santos, MD† Márcio Guerreiro, MD† Sandra Costa Fuchs, PhD† *Hospital Sanatório Partenon Porto Alegre-RS, Brazil †PPGCM UFRGS Porto Alegre-RS, Brazil