Confirmatory factor analysis of the WHO Violence Against Women instrument in pregnant women: results from the BRISA prenatal cohort

PLoS One. 2014 Dec 22;9(12):e115382. doi: 10.1371/journal.pone.0115382. eCollection 2014.

Abstract

Background: Screening for violence during pregnancy is one of the strategies for the prevention of abuse against women. Since violence is difficult to measure, it is necessary to validate questionnaires that can provide a good measure of the phenomenon. The present study analyzed the psychometric properties of the World Health Organization Violence Against Women (WHO VAW) instrument for the measurement of violence against pregnant women.

Methods: Data from the Brazilian Ribeirão Preto and São Luís birth cohort studies (BRISA) were used. The sample consisted of 1,446 pregnant women from São Luís and 1,378 from Ribeirão Preto, interviewed in 2010 and 2011. Thirteen variables were selected from a self-applied questionnaire. Confirmatory factor analysis was used to investigate whether violence is a uni-or-multidimensional construct consisting of psychological, physical and sexual dimensions. The mean-and-variance-adjusted weighted least squares estimator was used. Models were fitted separately for each city and a third model combining data from the two settings was also tested. Models suggested from modification indices were tested to determine whether changes in the WHO VAW model would produce a better fit.

Results: The unidimensional model did not show good fit (Root mean square error of approximation [RMSEA] = 0.060, p < 0.001 for the combined model). The multidimensional WHO VAW model showed good fit (RMSEA = 0.036, p = 0.999 for the combined model) and standardized factor loadings higher than 0.70, except for the sexual dimension for SL (0.65). The models suggested by the modification indices with cross loadings measuring simultaneously physical and psychological violence showed a significantly better fit compared to the original WHO model (p < 0.001 for the difference between the model chi-squares).

Conclusions: Violence is a multidimensional second-order construct consisting of psychological, physical and sexual dimensions. The WHO VAW model and the modified models are suitable for measuring violence against pregnant women.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cohort Studies
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Interviews as Topic
  • Models, Theoretical
  • Pregnancy
  • Sex Offenses
  • Stress, Physiological
  • Stress, Psychological
  • Surveys and Questionnaires
  • Violence*
  • World Health Organization

Grants and funding

This research was supported by: 1) Fundação de Amparo à Pesquisa do Estado de São Paulo (São Paulo Research Foundation; http://www.fapesp.br/), grant 2008-53593-0 to MAB; 2) Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazilian National Research Council; http://www.cnpq.br/), grants 471923/2011-7 and 561058/2010-5 to MAB and AAMS; 3) Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (Maranhão State Research Foundation; http://www.fapema.br/site2012/), grants 0035/2008, 00356/11 and 01362-11 to AAMS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.