Improving Identification of Patients With Rare Diseases Through Indirect Linkage Between French Medico-Administrative Claims Database (SNDS) and National Rare Disease Registry (BNDMR) in France: A Dual-Population Study
Author(s)
Reyhan Hasanova, MD,PhD1, Enkhgerel Nasanbat, MPH1, Asma Hamid, MD, MPH1, Cécile Pacheco, MSc1, Michael Keith, PhD, PharmD2, Miranda Bailey, B. Med Sci (Hons)2.
1Oracle, Paris, France, 2Rocket Pharmaceuticals, Cranbury, NJ, USA.
1Oracle, Paris, France, 2Rocket Pharmaceuticals, Cranbury, NJ, USA.
OBJECTIVES: Many rare diseases are recorded under non-specific ICD-10 codes in claims databases, which limits their traceability for research purposes. We aimed to describe the methodology used and outcomes attained in linking the French Rare Disease Registry (BNDMR) and the French National Health Data System (SNDS) to identify patients with Fanconi Anemia (FA) and a group of patients with Chronic Granulomatous Disease (CGD) or Leucocyte Adhesion Deficiency (LAD).
METHODS: Two separate cohorts of patients with FA and those with either CGD or LAD were selected from the BNDMR, then linked to corresponding SNDS cohorts of Aplastic Anemia (ICD-10 codes D61.0, D61.3) and of Functional Disorders of Neutrophils (ICD-10 codes D71, D84.8), between January 2010 and December 2022. An indirect iterative deterministic linkage was conducted to identify exact 1:1 linkage, using a combination of highly discriminant variables including month and year of birth, gender, month and year of death, and rare disease center number, as well as less discriminant variables, including consultation and hospitalization dates and department of residence.
RESULTS: Among BNDMR cohorts, 167 out of 266 FA patients (63%) and 159 out of 270 CGD or LAD patients (59%) were successfully linked to respective SNDS cohorts. The iterative use of a combination of three variables: age, gender, and department of residence, resulted in 44% and 41% of successful linkage for FA and FDN, respectively. In contrast, the following combinations of two variables: consultation and hospitalization dates, department and consultation or hospitalization dates, contributed minimally (<10%) to both cohorts. Non-linkage was primarily due to incomplete variables in the BNDMR.
CONCLUSIONS: Despite recent improvements, many records in the BNDMR still lack unique patient identifiers, limiting direct linkage. This study demonstrates a linkage approach between the BNDMR and the SNDS and supports future linkage strategies for studies focused in rare diseases.
METHODS: Two separate cohorts of patients with FA and those with either CGD or LAD were selected from the BNDMR, then linked to corresponding SNDS cohorts of Aplastic Anemia (ICD-10 codes D61.0, D61.3) and of Functional Disorders of Neutrophils (ICD-10 codes D71, D84.8), between January 2010 and December 2022. An indirect iterative deterministic linkage was conducted to identify exact 1:1 linkage, using a combination of highly discriminant variables including month and year of birth, gender, month and year of death, and rare disease center number, as well as less discriminant variables, including consultation and hospitalization dates and department of residence.
RESULTS: Among BNDMR cohorts, 167 out of 266 FA patients (63%) and 159 out of 270 CGD or LAD patients (59%) were successfully linked to respective SNDS cohorts. The iterative use of a combination of three variables: age, gender, and department of residence, resulted in 44% and 41% of successful linkage for FA and FDN, respectively. In contrast, the following combinations of two variables: consultation and hospitalization dates, department and consultation or hospitalization dates, contributed minimally (<10%) to both cohorts. Non-linkage was primarily due to incomplete variables in the BNDMR.
CONCLUSIONS: Despite recent improvements, many records in the BNDMR still lack unique patient identifiers, limiting direct linkage. This study demonstrates a linkage approach between the BNDMR and the SNDS and supports future linkage strategies for studies focused in rare diseases.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
RWD102
Topic
Real World Data & Information Systems
Disease
Rare & Orphan Diseases, Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)