Impact of ICD Indication and the P+P Intervention on Intimate Partner Physical and Mental Health

Abstract

Purpose/Aims: This dissertation examined the impact of the Patient+Partner (P+P) intervention on physical and psychological outcomes of partners of patients with implantable cardioverter defibrillators (ICDs), compared to a Patient-only (P-only) intervention. The study investigated whether: 1) partner demographic characteristics moderate intervention effects at 3 months; 2) self-efficacy mediates outcomes at 12 months; 3) patient ICD indication influences intervention effectiveness across a 12-month trajectory; and 4) evaluated measurement instruments used to assess partner outcomes in ICD contexts. Methods: This research includes: 1) secondary analysis of data from a randomized controlled trial (N=301 patient-partner dyads) from 12 acute care institutions across four states; 2) hierarchical regression for moderation analysis and path analysis for mediation testing; 3) General Linear Model with repeated measures for longitudinal analysis; and 4) systematic review of 17 quantitative studies (1990-2025) measuring partner outcomes following ICD implantation. Partner outcomes were assessed at baseline, 1-, 3-, 6-, and 12-month timepoints using validated instruments measuring physical function, psychological adjustment, relationship impact, and self-efficacy. Results: While demographic characteristics did not moderate intervention effects, self-efficacy at 3 months significantly mediated 12-month outcomes, with the P+P intervention enhancing partner self-efficacy (β=0.13, p=0.003), which subsequently improved physical health (β=0.11, p=0.018), mental health (β=0.24, p<0.001), reduced anxiety (β=-0.42, p<0.001) and depression (β=-0.22, p<0.001). Significant timeà ICD indication interactions emerged for mental health at 3 months (F=4.400, p=0.005) and 12 months (F=3.948, p=0.009), with partners of secondary prevention patients showing greater improvement in the P+P group. A significant three-way interaction (timeà ICD indicationà intervention) was observed for relationship quality at 12 months (F=2.667, p=0.048). The systematic review revealed significant methodological limitations in partner assessment, including insufficient physical health measurement and limited cardiac-specific instrumentation. Conclusion: The P+P intervention improves partner outcomes primarily through enhancing self-efficacy, with differential effectiveness across ICD indication categories. Partners of secondary prevention patients demonstrated particular vulnerability at baseline but achieved substantial improvement with the P+P intervention. The findings underscore the importance of partner-inclusive intervention in cardiac care, the necessity of tailoring interventions to specific clinical contexts, and the need for comprehensive, contextually-relevant measurement instruments for partner assessment.