Medical Journal of the Islamic Republic Of Iran

en Barriers and Facilitators to Participation in the Employees’ Health Cohort Study of Iran (EHCSIR): A Qualitative Content Analysis Epidemiology Epidemiology Original Research Original Research     Background: Declining enrollment poses a threat to epidemiological validity. Despite the increasing number of occupational health cohorts, evidence regarding employee-specific determinants in Iran remains limited. This study examined the perceived barriers and facilitators to participation in the Employees’ Health Cohort Study of Iran (EHCSIR) among staff at the Iran University of Medical Sciences.    Methods: A qualitative study was conducted using purposive sampling to include 48 individuals: EHCSIR participants, non-participants, and coordinators. The data comprised 23 semi-structured interviews (12 participants, 7 non-participants, and 4 coordinators), four focus groups (14 participants and 11 non-participants), and narrative responses from 954 eligible employees outlining reasons for non-participation. Conventional qualitative content analysis was applied in eight stages, with thematic saturation guiding the termination of data collection. Analytic rigor was maintained through member checking, peer debriefing, and audit trails, adhering to established trustworthiness criteria.    Results: The EHCSIR study identified barriers to employee participation across three domains: Organizational (insufficient managerial support, lack of replacement staffing, elevated mission costs, scheduling conflicts), Individual (family obligations, excessive workload, transportation challenges, distrust or fear of data disclosure, health limitations, inadequate information), and Cohort-specific (prolonged timelines, fatigue, lengthy questionnaires, lack of facilities, stringent requirements such as fasting or large-volume blood draws). Facilitators were also observed at three levels: Organizational (managerial endorsement and role modeling, paid leave, accessible transportation), Individual (health monitoring, cost savings, altruistic motivation, trust in the research team), and Cohort-specific (non-invasive methods, single-visit completion, extended assessment intervals, transparent in-person recruitment, organized management, supportive environment, systematic follow-up).    Conclusion: Organizational, logistical, and perceptual factors significantly influence participation in occupational health cohorts. Improving management, infrastructure, communication, and institutional trust can enhance recruitment and retention in EHCSIR and inform similar strategies both in Iran and internationally.   Qualitative Research, Cohort Studies, Occupational Health, Employee Participation, Barriers to Participation, Facilitators to Participation 574 584 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-4192-2&slc_lang=en&sid=1 Rezvan Rajabzadeh rajabzade.61@gmail.com 200319475328460098383 200319475328460098383 No Non-Communicable Diseases Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran Seyed Hamid Hosseini hosseini.ha60@gmail.com 200319475328460098384 0009-0005-1801-0236 No Non-Communicable Diseases Research Center, Sabzevar University of Medical Sciences, Sabzevar, Iran Seyed Abbas Motevalian motevalian.a@iums.ac.ir 200319475328460098385 200319475328460098385 Yes Research Center for Addiction and Risky Behaviors (ReCARB), Psychosocial Health Research Institute (PHRI), Iran University of Medical Sciences, Tehran, Iran