Although past-year exposure rates to psychological, physical and sexual IPV were similar among women and men, earlier-in-life exposure to all three forms of violence was significantly higher among women. Psychological, physical and sexual IPV often co-occurred. Factors associated with all forms of IPV for both women and men were poor/moderate social support, having grown up in a home with violence and being single, divorced or widowed. There was a tendency for women and men to report different social consequences of IPV; however, these differences were not statistically significant.
Sweden is often considered to be one of the most gender equal countries worldwide with its high participation of both women and men in, for example, the labour force; decision-making posts, such as the Parliament; and higher education. There is generally a low tolerance of violence and using violence in an intimate relationship is punishable by law. There exist few studies that assess IPV in the general population of both women and men; the present findings confirm that IPV is common in Sweden and that continued efforts towards ending IPV are warranted. Professionals working within the health care sector should be sensitive towards the possibility that a male or female patient may have been exposed to violence in their intimate relationship and that this violence may take place in many different contexts and lead to a diverse set of consequences. Health professionals are in a unique and valuable position to detect and document IPV.
Prevalence, frequency and co-occurrence of psychological, physical and sexual IPV
Previous studies have also found that past-year IPV estimates are similar in women and men, but that earlier-in-life IPV is higher in women [6, 34, 35]. It may be hypothesized that the two different time frames in part reflect differences in severity and impact of IPV between women and men, which have been found by previous studies [13, 22]. For example, considering that men generally experience less threatening and severe forms of IPV, they may not consider it particularly salient to remember later in life. Similarly, given that women are generally exposed to more severe forms of IPV with higher levels of physical injury, coercive control and fear, they may be more likely to report such violence also later in life . Given that several studies rely on past-year estimates–which, for example, have been considered to be the norm in community-based samples –this finding suggests that gender differences in exposure to IPV might go unnoticed if earlier-in-life estimates are not accounted for.
Our past-year exposure rates are similar to those reported in previous studies, with the exception of sexual IPV, which is usually found to be more prevalent among women than men [34, 38]. The earlier-in-life rates were somewhat lower in the current study compared to previous ones, [34, 39] which may be due to actual differences in prevalence and to differences in the definitions of IPV. In line with previous population-based studies,  severe acts of IPV were more seldom reported and our sample consisted mostly of the comparatively less severe acts of IPV.
The finding that women were exposed to all three forms of IPV more often than men within the earlier-in-life time frame (22.1% vs. 11.5%) is supported by other studies . However, corresponding rates during the past year were similar between women and men (4.5% vs. 3.9%). This further highlights the importance of considering the earlier-in-life time frame when assessing gender differences in exposure to IPV. Our exposure rates for psychological violence are higher than the other forms of IPV, which is in line with previous studies [4, 24].
Finally, it is worth noting that while support has been found for the VAWI’s validity among the female sample used in the current study,  the VAWI’s conceptual model was only partially replicated among the male sample . Instead, the boundaries between psychological, physical and sexual acts of violence were indistinct. Although further studies are needed in order to understand these results more fully, it nevertheless introduces a degree of uncertainty to our direct comparisons between women’s and men’s responses. Even if similar acts of violence are reported, the underlying constructs may differ. However, support for the instrument’s reliability was found among both samples.
Associated socio-demographic and psychosocial factors
We found that both poor to moderate social support, having grown up in a home with violence and being single, widowed or divorced increased the likelihood of reporting exposure to psychological and physical/sexual IPV for both women and men residing in Sweden, which is in line with previous literature from other countries [24, 41]. A possible explanation for the association between IPV and being single, widowed or divorced may be that the IPV was committed by a previous partner, which may be easier to report than violence experienced by a current partner.
Although most population-based studies investigate associated factors with physical and/or sexual IPV, our findings suggest that such factors are also associated with exposure to psychological IPV.
Educational level was also found to be associated with IPV, specifically having a university degree and/or having completed high school increased the likelihood for reporting psychological IPV for both men and women. Another population-based study assessing violence against men by several perpetrators and which was also conducted in Sweden has reported similar findings;  however, additional studies are needed to investigate this association further.
Social consequences of violence to everyday life, own use of violence and reasons for using such violence
Researchers have long underlined the importance of assessing consequences of IPV alongside the violent acts themselves as a way to consider the impact of IPV on women’s and men’s lives . In the current study, a traditional gender structure emerged to some extent from the results: only women reported consequences which related to children, whereas men more often reported consequences related to work. As more women than men reacted by divorcing their spouse or moving away from home to protect themselves from IPV, a possible interpretation is that women felt more threatened by the violence and therefore took more measures to end the relationship than men. This finding is supported by a study where women were more likely to dissolve a heterosexual relationship than men if there occurred severe forms of violence, whereas women and men were equally likely to dissolve a relationship if there occurred less severe forms of IPV .
Own use of violence
Although only 4.0% women and 4.3% men in the total population sample reported having used IPV sometime in their lives when assessed by a single item, a larger number of the respondents (9.6% women and 8.0% men of the total sample), however, gave a reason for having used IPV. This discrepancy may not be surprising as respondents may find it easier to give reasons for using violence than to define their use of violence as IPV, which has indeed been found to under-estimate true prevalence rates . Both women and men under-report their use of IPV although some studies have found women to under-report to a lesser extent than men . Reasons for this may be that women are more prone to remember their use of violence as they are transgressing a gender norm in using violence, whereas the use of violence is a more acceptable part of masculinity constructions and therefore may go more unnoticed or become normalized . Our finding that some report own use of violence may suggest that IPV takes place in several contexts, including relationships where the respondent is both exposed to and exposes his/her partner to violence, as shown by previous studies [19, 45].
Reasons given for using violence
Reasons given for perpetrating violent acts may also reflect on the context in which the IPV took place . The most commonly self-reported reason for using IPV by both the women and men was having felt offended and/or hurt, which has also been reported in the literature . The second most reported reason by women was feeling afraid and using violence in self-defence in a violent situation. Previous studies have often found women to use IPV in self-defence . The second most reported reason by men for having used violence was in a quarrel in which alcohol or illicit drugs was involved.
The main known limitation of postal surveys is low response rates . The current study included two reminders in an effort to minimize drop-out rates; however, the overall non-response rates were high for both women (38%) and especially for men (54.6%), which suggests caution in the interpretation of the results. The differing response rates among women and men also complicate the comparability of IPV between these two groups. Moreover, the response rates were lower among young, unmarried respondents, respondents with a lower annual income and respondents born outside Sweden. These groups have, especially among women , but also among men , been identified in the literature as particularly vulnerable to IPV. It is therefore possible that the current study has under-estimated the prevalence of IPV and consequently under-estimated the strengths of the associations between IPV and the socio-demographic factors. Also, an aggregate life-time variable was used to increase statistical power in the analyses assessing the associations between IPV and the socio-demographic factors. However, the exposure rates of IPV differed for women and men according to past-year and earlier-in-life time frames and it is therefore possible that the associated factors would have differed for women and men had they been assessed separately for the two time-frames. Finally, as the study was cross-sectional, we are not able to draw any conclusions about cause and effect.
Furthermore, both women and men have been found to under-report their exposure to violence in heterosexual intimate partnerships,  although some studies have found that men may also over-report such exposure while at the same time being perpetrators of IPV . Moreover, studies have found low to moderate inter-spousal agreement on the occurrence of IPV among heterosexual couples, both with regards to the frequency and the severity of the violence . Additionally, the violent acts that the respondents have been exposed to may differ in context. As such, we are not able to differentiate between, for example, a shove made in self-defence and a shove made in a context of assault and intimidation . As in all survey-based results relying on self-reports, caution should be used in interpreting the results.
Constructions of masculinity and femininity may influence how a person makes sense of and reports IPV, which in turn shapes results and conclusions [8, 11, 18]. An important research question is thus whether men and women define and report IPV in different, gendered ways. Future studies on this topic would conceivably help in interpreting survey-based data.