Leveraging Imperfection with MEDLEY A Multi-Model Approach Harnessing Bias in Medical AI

Farhad Abtahi^1,2,3*Mehdi Astaraki¹Fernando Seoane^1,2,4

• ¹Karolinska Institutet, Stockholm, Sweden
• ²Karolinska Universitetssjukhuset, Stockholm, Sweden
• ³Kungliga Tekniska Hogskolan, Stockholm, Sweden
• ⁴Hogskolan i Boras, Borås, Sweden

Bias in medical artificial intelligence is conventionally viewed as a defect requiring elimination. However, human reasoning inherently incorporates biases shaped by education, culture, and experience, suggesting their presence may be inevitable and potentially valuable. We propose MEDLEY (Medical Ensemble Diagnostic system with Leveraged diversitY), a conceptual framework that orchestrates multiple AI models while preserving their diverse outputs rather than collapsing them into a consensus. Unlike traditional approaches that suppress disagreement, MEDLEY documents model-specific biases as potential strengths and treats hallucinations as provisional hypotheses for clinician verification. A proof-of-concept demonstrator for differential diagnosis was developed using over 30 large language models, preserving both consensus and minority views, rendering diagnostic uncertainty and latent biases transparent to support clinical oversight. While not yet a validated clinical tool, the demonstration illustrates how structured diversity can enhance medical reasoning under the supervision of clinicians. By reframing AI imperfection as a resource, MEDLEY offers a paradigm shift that opens new regulatory, ethical, and innovation pathways for developing trustworthy medical AI systems.