Abstract: SA-PO739
Elicitation of Physician Opinions of the Impact of Dynamic Changes in Biomarkers on Perceived Relapse Propensity in ANCA-Associated Vasculitis: Impact of Individual Expert and Patient Characteristics
Session Information
- ANCA-Associated Vasculitis, Anti-GBM Disease, and Other RPGN
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Nic an Riogh, Eithne Muireann, Trinity Translational Medicine Institute, Trinity College Dublin, Dublin, Ireland
- Hackenberg, Maren, Institute of Medical Biometry and Statistics, University of Freiburg, Freiburg, Germany
- Hess, Moritz, Institute of Medical Biometry and Statistics, University of Freiburg, Freiburg, Germany
- Walsh, Cathal D., School of Computer Science and Statistics, Trinity College Dublin, Dublin, Ireland
- White, Arthur, School of Computer Science and Statistics, Trinity College Dublin, Dublin, Ireland
- Little, Mark Alan, Trinity Translational Medicine Institute, Trinity College Dublin, Dublin, Ireland
Background
ANCA-associated vasculitis(AAV) has a relapsing and remitting course. Accurate predictive algorithms do not exist. Prior knowledge can help to specify Bayesian prior distributions or generate synthetic observations to augment available data. To elicit prior knowledge on changes in time-varying variables and clinical endpoints, we assessed the beliefs of experts on how biomarker changes affect relapse probability and treatment intention.
Methods
We devised 10 synthetic clinical cases. Experts (immunology n=1, nephrology n=5, rheumatology n=4) with an average of 20.4 years’ experience were recruited from Ireland, UK, Spain, Netherlands, Germany and Australia. 10 time-varying biomarkers were selected: creatinine, anti-MPO, anti-PR3, sCD163, lymphocyte count, urine protein, urine blood, IgG level and CD19 count. We assessed the perception of relapse risk and intention to change immunosuppression(IS) over 9-24 months. The questionnaire was refined using a Delphi approach. We assessed biomarker rise and fall, positive to negative, or negative to positive switch. The 290-question survey was conducted using a dimensionless scale with a slider to capture responses with extremes of responses labelled on opposite ends.
Results
Reduction in anti-PR3 and anti-MPO were associated with intention to reduce IS (median 46.5 and 38.5) and reduced relapse risk perception (41.0 and 42.0). A rise in anti-PR3 and anti-MPO were strongly associated with a decision not to reduce IS (81.0 and 82.5) and increased relapse risk perception (72.0 and 68.0). Clinicians intended to reduce IS if lymphocyte count (33.5) or IgG (30.0) levels fell, but this did not influence perception of relapse risk (50.0 - lymphocyte count, 50.0 - IgG). There were higher discrepancies in the responses on stable patient characteristics.
Conclusion
Clinical experts were more confident in reducing IS than relapse probability. This reflects the challenge of accurately identifying long term remission in AAV. Greater variability in responses regarding IS reduction reflects variation in clinical practice. Greater concordance was seen in responses on relapse prediction. This study guides future development of predctive algorithms using Bayesian methodologies.