Psychometric properties of the WHO Violence Against Women instrument in a female population-based sample in Sweden: a cross-sectional survey

OBJECTIVE To explore psychometric properties of the Violence Against Women instrument in a randomly selected national sample of women (N=573) aged 18-65 years and residing in Sweden. DESIGN Cross-sectional survey study. SETTING Sweden. PARTICIPANTS A postal survey was sent to 1006 women between January and March 2009, during which 624 women (62%) returned the questionnaire. 51 women who did not answer any of the violence items were excluded from the analyses, resulting in a final sample of 573 women. PRIMARY AND SECONDARY OUTCOME MEASURES Self-reported exposure to psychological, physical and sexual intimate partner violence. RESULTS Cronbach's α coefficients were 0.79 (psychological scale), 0.80 (physical scale), 0.72 (sexual scale) and 0.88 (total scale). A predetermined three-component solution largely replicated the explored three component conceptual model of the Violence Against Women instrument. The instrument was able to discriminate between groups known from previous studies to differ in exposure to physical and/or sexual violence, that is, respondents with poor versus good self-rated health and witnessed versus not witnessed physical violence at home when growing up. Past-year prevalence of physical (8.1%; 95% CI 5.9 to 10.3) and sexual (3%; 1.6 to 4.4) violence was similar to that reported in other Nordic studies; however, earlier-in-life prevalence was lower in the current study (14.3%; 95% CI 11.4 to 17.2 and 9.2%; 95% CI 6.8 to 11.6, respectively). Reported exposure rates were higher than those obtained from a concurrently administered instrument (NorVold Abuse Questionnaire). CONCLUSIONS The Violence Against Women instrument demonstrated good construct validity and internal reliability in an adult female population in Sweden. However, further studies examining these and other psychometric properties need to be conducted in other countries.