The evidence for effective interventions to reduce IPV and improve abused women's wellbeing is very limited, especially for women still living with partners, which includes half the participants in this study. In this first primary care randomised trial of non-professional mentor support for women abused by intimate partners, there was evidence of a true difference of reduced partner violence between mentored women referred from primary care populations compared with those not mentored (although PS analysis weakened the evidence). There was weak evidence for other findings suggestive of mentor benefit in reducing depression and improving physical and mental wellbeing.
All findings were consistently in favour of the intervention arm, and the lack of stronger evidence for the differences may be due in part to the smaller than anticipated numbers of participants, resulting in reduced power to detect small, but meaningful differences. Despite substantial efforts to enhance clinician IPV knowledge, skills and resources, and clinician agreement to the randomised trial design, MOSAIC suffered from low rates of identification and referral from both nurses and doctors, particularly in the trial's comparison arm. There is evidence from clinician interviews of two problems. The first is that despite considerable training, many clinicians continued to feel under-confident to ask about IPV. We conclude that major systemic challenges remain to be overcome before health care providers feel sufficiently supported and confident to identify and effectively care for the abused women in their respective populations. Second, there was clearly a reluctance to refer women in the comparison arm in comparison with the intervention arm, due to a perception of no benefit for this group of vulnerable women even after feedback of positive comments about participation from women recruited to the comparison arm. This may also contribute to bias.
Thus, the major threat to the validity of the study was clinician non-blinding. This aspect of the design was thought to be unavoidable, as the mentor-mother program was designed to be integrated with primary care and women did talk about mentoring with their clinician. Low referrals overall and the 2:1 ratio of recruited women in the intervention versus comparison arms, introduced potential selection bias and had a substantial impact on our final sample size and our power to provide better evidence for intervention effects. Our approach to addressing selection bias involved adding PS to our analysis. While the PS analysis did result in altered effect sizes, it did not alter the direction of effects. The PS analysis did not alter the consistent trend towards more favorable outcomes in the intervention arm of the trial.
Could we have avoided the problem? One solution would have been to randomise individual women once they had been referred to the research team. With hindsight this has some merit, given the small number of women any individual clinician actually referred, which meant that contamination may have been unlikely. However, it is also unclear whether the trial would have experienced even lower numbers of referrals if clinicians had known that women referred would only have a 50:50 chance of receiving the offer of a mentor.
The self-report nature of the measures and the fact that we measured outcomes immediately after the intervention was completed, may be additional sources of bias. It remains unknown if any beneficial effect was sustained beyond 12 months.
In the only other mentoring study - Madres a Madres, a study among an abused pregnant population where the majority of mentoring was provided by telephone and only up until the time of birth-McFarlane et al found that the benefits of mentoring during pregnancy were not sustained to 18 months after birth[35, 18]. Birth and infancy are periods of considerable strain among families where there is no IPV, so the additional stress for mothers experiencing IPV is self-evident, whenever the abuse commenced. The emotional and practical support from mentors during this infancy period, sustained for up to a year as in the current study, may explain why our findings suggest some benefit.
Our study findings are consistent with the growing number of studies providing evidence of the benefit of home-visiting for vulnerable mothers[36–38]. Yet, in the great majority of these, home visiting is provided by nurses and there is no evidence to date that nurse visits are effective when there is IPV present. Nurses are often mandated to report child abuse and many women affected by IPV are fearful of losing their children or have many professionals already involved in their care. Given the findings of the current study we suggest there is a role for non-professional befriending models in the spectrum of professional and non-professional responses to IPV.
Further research is needed to confirm the findings of MOSAIC and to determine whether positive effects can be sustained over the longer term. MOSAIC will contribute to the small but increasing trial evidence for advocacy interventions for women in health care settings, demonstrated in the recent Cochrane systematic review. Given the problems experienced in the current study with clinician identification and referral, despite significant investment in upskilling and support resources, the question of what more can be done to enhance clinician care when IPV is present - for women, their children and in management of abusing partners - requires further investigation.