TY - JOUR
T1 - Registration of Amyotrophic Lateral Sclerosis
T2 - Validity in the Danish National Patient Registry
AU - Levison, Lotte Sahin
AU - Jepsen, Peter
AU - Andersen, Henning
N1 - Publisher Copyright:
© 2024 Levison et al.
PY - 2024/6
Y1 - 2024/6
N2 - Purpose: Health care databases are a valuable source for epidemiological research on amyotrophic lateral sclerosis (ALS) if diagnosis codes are valid. We evaluated the validity of the diagnostic codes for ALS in the Danish National Patient Registry (DNPR). Patients and Methods: We obtained data from the DNPR for all adult (>17 years) patients registered with ALS in Denmark between 1987 and 2022 (median population of 4.2 million during the study period). We randomly selected adult patients living in the North Denmark Region and Central Denmark Region (median population 1.4 million), with a primary discharge diagnosis code of ALS, diagnosed at three departments of neurology. We retrieved and reviewed medical records and estimated the positive predictive value (PPV) of the ALS diagnosis. Results: Over 36 years, we identified 5679 patients. From the validation cohort of 300 patients, we were able to retrieve 240 (80%) medical records, and 215 ALS diagnoses were confirmed. The overall positive predictive value was 89.6% (95% confidence interval (CI): 85.1–92.8). The highest PPV was achieved for diagnoses registered for patients aged ≥70 years (93.8; 95% CI: 86.2–97.3) compared to patients <60 years (83.4; 95% CI: 73.3–90.7). Conclusion: We found a high PPV of primary diagnostic codes for ALS from Danish departments of neurology, demonstrating high validity. Thus, the DNPR is a well–suited data source for large-scale epidemiological research on ALS.
AB - Purpose: Health care databases are a valuable source for epidemiological research on amyotrophic lateral sclerosis (ALS) if diagnosis codes are valid. We evaluated the validity of the diagnostic codes for ALS in the Danish National Patient Registry (DNPR). Patients and Methods: We obtained data from the DNPR for all adult (>17 years) patients registered with ALS in Denmark between 1987 and 2022 (median population of 4.2 million during the study period). We randomly selected adult patients living in the North Denmark Region and Central Denmark Region (median population 1.4 million), with a primary discharge diagnosis code of ALS, diagnosed at three departments of neurology. We retrieved and reviewed medical records and estimated the positive predictive value (PPV) of the ALS diagnosis. Results: Over 36 years, we identified 5679 patients. From the validation cohort of 300 patients, we were able to retrieve 240 (80%) medical records, and 215 ALS diagnoses were confirmed. The overall positive predictive value was 89.6% (95% confidence interval (CI): 85.1–92.8). The highest PPV was achieved for diagnoses registered for patients aged ≥70 years (93.8; 95% CI: 86.2–97.3) compared to patients <60 years (83.4; 95% CI: 73.3–90.7). Conclusion: We found a high PPV of primary diagnostic codes for ALS from Danish departments of neurology, demonstrating high validity. Thus, the DNPR is a well–suited data source for large-scale epidemiological research on ALS.
KW - amyotrophic lateral sclerosis
KW - epidemiology
KW - international classification of disease codes
KW - positive predictive value
KW - registries
UR - http://www.scopus.com/inward/record.url?scp=85196419568&partnerID=8YFLogxK
U2 - 10.2147/clep.s458661
DO - 10.2147/clep.s458661
M3 - Journal article
AN - SCOPUS:85196419568
SN - 1179-1349
VL - 16
SP - 409
EP - 415
JO - Clinical epidemiology
JF - Clinical epidemiology
ER -