Longitudinal effectiveness of a woman-led, nurse delivered health promotion intervention for women who have experienced intimate partner violence: iHeal randomized controlled trial

BACKGROUND: Intimate partner violence (IPV) threatens the safety, health and quality of life of women worldwide. Comprehensive IPV interventions that are tailored, take a long-term view of women's needs, including health concerns, and maximize choice and control, have the potential to effectively address heath and safety concerns. Few such interventions have been tested, including in the Canadian context.

METHODS: A parallel randomized controlled trial of adult (age 19 + years), English-speaking, Canadian women with histories of IPV randomized either to iHEAL, a tailored health promotion intervention delivered by Registered Nurses over 6-7 months, or to community service information (usual care control). Primary (Quality of Life, PTSD symptoms) and secondary outcomes (Depression, Confidence in Managing Daily Life, Chronic Pain, IPV Severity) were measured at baseline and 6, 12 and 18 months post-intervention via an online survey. Generalized estimating equations were used to test for differences by study arm in intention-to-treat (full sample) and per protocol (1 + iHEAL visit) analyses focussing on short-term (immediately post-intervention) and longer-term (1 year post-intervention) effects. Selected process evaluation data were summarized using descriptive statistics.

RESULTS: Of 331 women enrolled, 175 were randomized to iHEAL (135 who engaged in 1 + visits) and 156 to control. Women who received iHEAL showed significantly greater short-term improvement in Quality of Life compared to the control group, with these effects maintained 1 year later. Changes in PTSD Symptoms also differed significantly by group, with weaker initial effects that were stronger 1 year post-intervention. Significant moderate, short- and longer-term group effects were also observed for Depression and Confidence in Managing Daily Life. IPV Severity decreased for both groups, with significant immediate effects in favour of the intervention group that grew stronger 1 year post-intervention. There were no changes in Chronic Pain.

CONCLUSION: iHEAL is an effective, acceptable and safe intervention for diverse groups of women with histories of IPV. Trial results provide a foundation for implementation and ongoing evaluation in health care settings and systems. Delayed effects noted for PTSD Symptoms and IPV Severity suggest that longer-term assessment of these outcomes may be needed in trials of IPV interventions. TRIAL REGISTRATION: Clinicaltrials.gov ID NCT03573778 (Registered on June 29, 2018).