Psychometric properties of the Brazilian Portuguese versions of the 29- and 13-item scales of the Antonovsky's Sense of Coherence (SOC-29 and SOC-13) evaluated in Brazilian cardiac patients.

AIM AND
OBJECTIVES: To assess the construct validity and reliability of the Brazilian Portuguese versions of the 29- and 13-item scales of the Antonovsky's Sense of Coherence Scale (SOC-29 and SOC-13).
BACKGROUND: Antonovsky's Sense of Coherence Questionnaire was developed to measure the main construct of the salutogenic theory, the sense of coherence. The use of the sense of coherence by health professionals might help identifying specific coping strategies used by person with chronic illness.
DESIGN: Cross-sectional study.
METHODS: The SOC-29 has been culturally adapted to Brazilian Portuguese language. In this study, we assessed its psychometric properties (construct validity and internal reliability) tested on 203 cardiac patients. The SOC-13 was tested on another 100 cardiac patients hospitalised in the same hospital. The construct validity of both versions was investigated through Pearson correlation between the measures of sense of coherence and of correlated constructs (self-esteem, depression and age), analysis of the principal components and comparison of distinct groups (male vs. female). The internal reliability for both versions was evaluated by Cronbach's alpha.
RESULTS: For both versions, the construct validity assessments showed strong positive correlations between sense of coherence and self-esteem and strong negative correlations between sense of coherence and depression (convergent validity), and weak correlation between sense of coherence and age (divergent validity). Principal component analysis supported in part the presence of a single component (unidimensionality). Differences in sense of coherence were found by sex with SOC-29, but not with SOC-13. Cronbach's alpha coefficients showed satisfactory internal consistency in both versions.
CONCLUSIONS: The Brazilian Portuguese versions of SOC-29 and SOC-13 can be considered valid and reliable for the populations studied. More studies need to be performed to assess these proprieties in other Brazilian populations. RELEVANCE TO CLINICAL PRACTICE: This scale can be used in research and clinical practice in Brazil to assess nursing interventions aimed at decreasing stress during cardiac rehabilitation.