
The authors have reported a case of a male patient in his 70s with end-stage renal disease on peritoneal dialysis and sevelamer use for hyperphosphatemia. The patient's hospital course was complicated by pulseless electrical activity cardiac arrest, infective endocarditis, and bacteremia. During the hospital course, the patient developed 2 episodes of large-volume bloody stools accompanied by hypotension. Colonoscopy was notable for ulcerated and pseudomembrane-covered mucosa in the rectum. Histopathology showed ulcerated colonic mucosa containing "scale- like" foreign crystals, consistent with sevelamer resin. Gastrointestinal bleeding secondary to sevelamer use has rarely been reported, with only 36 cases documented globally as of 2024. The cardiac arrest and hemodynamic instability may have contributed to mucosal vulnerability in the setting of sevelamer exposure. To the knowledge of the authors, this is the first reported case of sevelamer-induced gastrointestinal injury in a patient with recent cardiac arrest. No additional episodes of bleeding were observed after discontinuation of sevelamer.
INTRODUCTION Males are persistently underrepresented in longitudinal health research, yet effective strategies to improve their recruitment and retention remain limited. This study examined motivational factors, engagement strategies, and retention approaches among males in the context of the Connect for Cancer Prevention Study (Connect), a large National Cancer Institute-sponsored longitudinal observational study. METHODS The authors conducted a qualitative study using individual and group interviews with 2 cohorts of Kaiser Permanente Northwest male members: enrolled Connect participants (n = 22) and Connect-eligible members who had not enrolled (n = 13). Interviews explored motivations for participation, barriers to engagement, and retention strategies. Transcripts were analyzed using thematic analysis with NVivo software. RESULTS Distinct motivational profiles emerged across cohorts. Enrolled participants were primarily driven by altruism, family cancer history, and civic responsibility, while Connect-eligible participants approached participation transactionally, prioritizing financial incentives, convenience, and minimal disruption to daily routines. Across both groups, key facilitators included institutional trust, practitioner endorsement, and low-burden participation mechanisms. Retention was linked to consistent communication, visible study progress, and a sense of community. DISCUSSION Recruitment and retention require distinct but complementary strategies. Initial enrollment is best supported by addressing practical barriers and communicating tangible benefits, while long-term retention depends on fostering connection and demonstrating impact. These findings offer actionable, gender-sensitive guidance for improving participation among males in longitudinal health research. CONCLUSION Gender-sensitive, equity-informed approaches are essential for engaging males, particularly those from underrepresented groups, in longitudinal research. Strategies addressing masculinity norms, socioeconomic context, and institutional trust will strengthen the diversity and generalizability of observational study findings.