Implementation of an interprofessional collaborative care model in Korean medicine home-based primary care: protocol for a type 2 hybrid effectiveness–implementation study

South Korea faces a growing population of homebound older adults, yet structured home-based primary care (HBPC) infrastructure remains underdeveloped. Although Korean medicine (KM) doctors participate in the government-led long-term care home medical center pilot, evidence on their systematic integration into interprofessional teams remains limited. This study aims to evaluate preliminary clinical signals and implementation outcomes of a KM-based interprofessional collaborative care model. This protocol describes a type 2 hybrid effectiveness–implementation study using a single-group pre–post design. The study will be conducted at a social cooperative in Daejeon, Republic of Korea, evaluating an innovation codesigned with local stakeholders. The model uses a dual-team structure: a core team (KM doctor, nurse, social worker) provides routine care through seven standardized pathways adapted from the WHO Integrated Care for Older People guidelines, while an extended team (medical doctor and allied health professionals) addresses complex needs via standardized closed-loop referrals. The target sample includes 100 homebound innovation recipients and all eligible innovation deliverers. The primary clinical outcome is the change in systolic blood pressure from baseline to 4-month follow-up; secondary clinical indicators include diastolic blood pressure, random blood glucose, and glycated hemoglobin (HbA1c), among others. Implementation outcomes will be evaluated using the RE-AIM framework, with the primary implementation outcome being collaboration execution, defined as the proportion of completed collaborative referrals and replies among identified collaboration needs in recipients requiring collaboration. A mixed-methods approach will be used: quantitative analyses will assess pre–post changes in clinical and implementation indicators, and qualitative analyses of focus group interviews and field logs will examine implementation determinants and adaptations using CFIR-informed directed content analysis. Findings will be integrated using a joint display matrix. This study will generate practice-relevant evidence on optimizing bidirectional collaboration between KM and medical services in HBPC. By clarifying role delineation and referral mechanisms, the findings will inform refinement and potential scale-up of integrated HBPC models for frail, homebound older adults. Clinical Research Information Service (KCT0011285; registered December 9, 2025; URL: https://cris.nih.go.kr/cris/search/detailSearch.do?seq=31890%26search_page=L ).