The Swiss Integrated Care (INCA) Study: Description of a Novel Prospective Cohort of Patients and Caregivers in Reimbursed Informal Care

Methods INCA is a prospective, single-center cohort study with nationwide recruitment. Participation is open to adult patients and informal caregivers who provide paid informal care through home care agencies (Spitex organizations) in Switzerland. Eligible participants are enrolled consecutively. The cohorts primary outcome is health-related quality of life of patients, assessed monthly through patient-reported outcome measures. Secondary outcomes include home care needs, including the overall health and well-being of patients (measured semi-annually), the type, amount, and quality of care (recorded daily), and caregiver burden and resilience (measured quarterly). Additional analysis will include structured medical data, extracted from patient-provided documents using Optical Character Recognition (OCR) technology and analysed using Large Language Models (LLM). Results Since recruiting started in July 2025, the cohort has enrolled 855 patients and 851 caregivers. Among patients, 53% are female, with a median age of 73 years. Caregivers are predominantly female (72%) with a median age of 56 years. Most patients experience impairments in physical functioning and participation in social roles. Among them, 85% require less than two hours of care per day, though care needs vary considerably. This is further reflected in the multi-attribute utility, where the overall PROMIS-Preference (PROPr) score is very low for most patients, with a median of 0.102, indicating a substantial need for medical assistance and care. With a median of 9 comorbidities, health-related quality of life is overall low for most patients. Cardiovascular and endocrine & metabolic diseases are amongst the most prevalent, affecting 69% and 65% of patients with available diagnoses (n=771). Certain diagnostic pairs occur more frequently than expected by chance, suggesting underlying links between disease categories. Conclusions INCA responds to a growing policy need for robust evidence on how new models of informal care are associated with the health and well-being of patients and their caregivers. Its longitudinal design, combining patient- and caregiver-reported data with medical records and innovative data extraction methods, will lay the groundwork for a better understanding of new informal care models in real-world settings. INCAs findings are expected to have significant policy relevance and contribute to evidence-based policies on long-term care at home in Switzerland.