Patient navigation initiatives aim to improve the coordination of healthcare by reducing the barriers patients encounter when seeking access to appropriate services. These types of interventions are currently being tested both within Germany and internationally. A common obstacle in such research, as with most clinical trials, is developing recruitment methods that successfully enroll enough participants from the target groups. The results presented here aim to share insights and experiences regarding a common challenge in healthcare research: identifying factors that influence patient participation and refusal in studies testing new interventions, and how these factors can guide study design. This study, part of a mixed-methods feasibility evaluation involving randomized and cohort components, systematically recorded the recruitment process for a patient-focused navigation program. Between June 2021 and September 2022, individuals with lung cancer or stroke were recruited from inpatient wards and specialized outpatient clinics across urban and rural regions of Germany. Data were collected on why some patients were excluded or not approached, as well as the reasons patients declined participation. Quantitative findings were analyzed descriptively, and thematic analysis was applied to interviews with recruitment staff to capture their perspectives. Among screened individuals, eligibility rates ranged from 74% to 76.5% for stroke patients and 91% to 93% for those with lung cancer. Of those eligible, recruitment efforts reached 44% to 46.9% of inpatients and 73% of outpatients. Factors preventing patients from approaching were primarily linked to organizational or situational constraints. Common reasons patients refused involvement included feelings of being overwhelmed (noted in stroke patients) and perceiving the study as irrelevant (noted in lung cancer patients). The lessons learned and recruitment challenges encountered during this feasibility study provide valuable insights for refining patient enrollment strategies in future trials focusing on age-related health conditions.
