PhenX Toolkit Measurement Protocols for Sickle Cell Disease Pain

Sickle cell disease (SCD) is a hemoglobinopathy affecting more than 8 million people worldwide. Pain, acute and chronic, is the most common and debilitating symptom of SCD. The use of standardized and well-established tools and protocols by researchers and clinicians for data collection can facilitate analyzing data from across different studies and, potentially, uncover previously unknown aspects of SCD pain. The PhenX (consensus measures for Phenotypes and eXposures) Toolkit (https://www.phenxtoolkit.org) is a web-based catalog of recommended measurement protocols and associated bioinformatics tools that facilitate study design and promote cross-study data integration and analyses. In 2019, the National Heart, Lung, and Blood Institute provided co-funding to the PhenX Toolkit to expand its collection of SCD-related protocols, strengthening the framework for data sharing across research projects. In 2021, a Working Group of 10 researchers and clinicians with expertise in SCD pain was assembled to recommend protocols for inclusion in the Toolkit. Using a consensus-driven approach that incorporated input from the scientific community, the SCD Pain Working Group selected protocols based on availability, researcher/participant burden, and validation status and prioritized well-established and broadly validated measures. Released in May 2022, the final selection included 22 protocols covering key dimensions of SCD pain, such as intensity, sensory characteristics, location, interference, physical mobility, impact on daily activities, and coping strategies. Consistent use of these protocols will improve data quality and comparability and will support meta-analyses. Adoption of these protocols could facilitate clinical guidelines and enhance comparative effectiveness research and implementation science for SCD pain management.