Supplier-induced demand in Iran’s health insurance system: a qualitative health systems analysis of drivers and control strategies

Supplier-induced demand (SID) is a major challenge in health systems, contributing to unnecessary healthcare utilization, inefficient resource allocation, rising costs, and financial pressure on health insurance organizations. Most studies have focused on individual determinants of SID, with limited attention to the interactions among health-system functions and stakeholders. This study aimed to identify strategies for controlling SID within Iran’s health insurance system from an institutional and governance perspective. A qualitative study was conducted using semi-structured interviews with 25 key informants, including policymakers, health insurance managers, supervisory experts, health-system specialists, and medical university faculty members. Participants were selected through purposive and snowball sampling. Interviews were transcribed verbatim and analyzed inductively using Braun and Clarke’s thematic analysis. In a secondary interpretive stage, the emergent themes were mapped to the World Health Organization’s Health System Building Blocks and interpreted using concepts from information asymmetry and Principal–Agent Theory. Six interrelated domains relevant to the emergence and control of SID were identified. Financial incentives, particularly fee-for-service payment and dependence on service volume, were perceived as important contributors. Governance challenges, including fragmented oversight, weak coordination, and limited accountability, were reported to reduce the effectiveness of monitoring. Participants emphasized the potential role of integrated health information systems in reducing information asymmetry and improving transparency. Weak referral pathways and ineffective gatekeeping were associated with unnecessary specialist utilization. Provider-related factors, including workload pressures, professional accountability, and limited training in resource stewardship, were also viewed as influencing clinical decision-making. Low patient health literacy and limited engagement further increased vulnerability to unnecessary services. Proposed control strategies included strategic purchasing, payment reform, strengthened governance, integrated information systems, effective referral mechanisms, provider development, and patient empowerment. These findings informed a conceptual framework illustrating the proposed interactions among insurers, providers, patients, and health-system domains. The findings suggest that SID in Iran’s health insurance system is a multidimensional phenomenon shaped by interacting financial, governance, informational, provider-related, and patient-related factors. Its control may therefore require coordinated reforms across multiple health-system domains rather than reliance on isolated interventions. The proposed framework offers a systems-oriented interpretation that may inform future policy design and empirical research but requires further examination using patient, frontline-provider, and administrative data.