Variability in Definitions and Measurement Approaches of Vaso-Occlusive Crises (VOCs) in Sickle Cell Disease (SCD): A Targeted Literature Review of Global Real-World Evidence (RWE) Studies
Author(s)
Diana M. Stan, PhD1, David Purdie, MSC2, Anna Filonenko, DrPH, Msc3, Mert Ceyhan, MD, MSc4, Federico Montealegre-Golcher, MSc5;
1Pfizer, Bucharest, Romania, 2Pfizer Inc, San Francisco, CA, USA, 3Pfizer Inc, Germany, Germany, 4Pfizer Inc, Dubai, United Arab Emirates, 5Pfizer Inc, Miami, FL, USA
1Pfizer, Bucharest, Romania, 2Pfizer Inc, San Francisco, CA, USA, 3Pfizer Inc, Germany, Germany, 4Pfizer Inc, Dubai, United Arab Emirates, 5Pfizer Inc, Miami, FL, USA
Presentation Documents
OBJECTIVES: VOCs in SCD pose significant challenges for generating robust RWE due to the lack of standardized definitions and measurement tools. These challenges complicate clinical management and hinder consistent research comparisons. This study aims to address this by conducting a targeted literature review (TLR) to explore the variability in VOC definitions and measurement approaches across global RWE studies.
METHODS: A TLR was conducted to assess the operational and conceptual VOC definitions in RWE studies and systematic literature reviews, published between January 2020 and December 2024, across PubMed and MEDLINE. Specific inclusion criteria were based on VOC measurement approaches, including ICD codes, PROs, length of hospital stay (LOS), frequency of admissions, and pain medication usage.
RESULTS: Of 53 studies identified, 40 met the inclusion criteria. Most studies conducted in the US used claims data (e.g., Medicaid), while non-U.S. studies relied on prospective cohort designs. Retrospective studies accounted for ~70%, with prospective studies comprising 15%. Three main dimensions of VOC definitions were identified: Healthcare Utilization-Driven VOCs (hospitalizations, outpatient visits, emergency department visits, or telehealth consultations, often composite and inconsistently defined), Patient-Reported VOCs (self-reported crises managed at home or in clinical settings), and Composite and Severity-Focused VOCs (incorporating ICD codes, PRO measures, pain medication usage, or hospital LOS). Inpatient VOCs were primarily identified using ICD codes (ICD-9-CM 282.62, ICD-10-CM D57.00), with PROs and LOS often used to measure severity. VOCs led to hospital LOS of 3-7 days, with pain intensity peaking in the first 48 hours.
CONCLUSIONS: This review highlights the need for standardized VOC definitions and measurement approaches to improve RWE validity. These findings will guide future VOC validation studies, enabling improved VOC measurement in RWD. Ultimately, this approach could enhance VOC identification in RWD, support better clinical management, provide more consistent evidence for targeted treatments, aligning with FDA RWD/E guidelines.
METHODS: A TLR was conducted to assess the operational and conceptual VOC definitions in RWE studies and systematic literature reviews, published between January 2020 and December 2024, across PubMed and MEDLINE. Specific inclusion criteria were based on VOC measurement approaches, including ICD codes, PROs, length of hospital stay (LOS), frequency of admissions, and pain medication usage.
RESULTS: Of 53 studies identified, 40 met the inclusion criteria. Most studies conducted in the US used claims data (e.g., Medicaid), while non-U.S. studies relied on prospective cohort designs. Retrospective studies accounted for ~70%, with prospective studies comprising 15%. Three main dimensions of VOC definitions were identified: Healthcare Utilization-Driven VOCs (hospitalizations, outpatient visits, emergency department visits, or telehealth consultations, often composite and inconsistently defined), Patient-Reported VOCs (self-reported crises managed at home or in clinical settings), and Composite and Severity-Focused VOCs (incorporating ICD codes, PRO measures, pain medication usage, or hospital LOS). Inpatient VOCs were primarily identified using ICD codes (ICD-9-CM 282.62, ICD-10-CM D57.00), with PROs and LOS often used to measure severity. VOCs led to hospital LOS of 3-7 days, with pain intensity peaking in the first 48 hours.
CONCLUSIONS: This review highlights the need for standardized VOC definitions and measurement approaches to improve RWE validity. These findings will guide future VOC validation studies, enabling improved VOC measurement in RWD. Ultimately, this approach could enhance VOC identification in RWD, support better clinical management, provide more consistent evidence for targeted treatments, aligning with FDA RWD/E guidelines.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
RWD8
Topic
Real World Data & Information Systems
Topic Subcategory
Distributed Data & Research Networks, Reproducibility & Replicability
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Rare & Orphan Diseases