%0 Journal Article %@ 2291-9694 %I JMIR Publications %V 10 %N 12 %P e42379 %T Construction of Cohorts of Similar Patients From Automatic Extraction of Medical Concepts: Phenotype Extraction Study %A Gérardin,Christel %A Mageau,Arthur %A Mékinian,Arsène %A Tannier,Xavier %A Carrat,Fabrice %+ Institute Pierre Louis Epidemiology and Public Health, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, 27 rue de Chaligny, Paris, 75012, France, 33 678148466, christel.ducroz-gerardin@iplesp.upmc.fr %K natural language processing %K similar patient cohort %K phenotype %K systemic disease %K NLP %K algorithm %K automatic extraction %K automated extraction %K named entity %K MeSH %K medical subject heading %K data extraction %K text extraction %D 2022 %7 19.12.2022 %9 Original Paper %J JMIR Med Inform %G English %X Background: Reliable and interpretable automatic extraction of clinical phenotypes from large electronic medical record databases remains a challenge, especially in a language other than English. Objective: We aimed to provide an automated end-to-end extraction of cohorts of similar patients from electronic health records for systemic diseases. Methods: Our multistep algorithm includes a named-entity recognition step, a multilabel classification using medical subject headings ontology, and the computation of patient similarity. A selection of cohorts of similar patients on a priori annotated phenotypes was performed. Six phenotypes were selected for their clinical significance: P1, osteoporosis; P2, nephritis in systemic erythematosus lupus; P3, interstitial lung disease in systemic sclerosis; P4, lung infection; P5, obstetric antiphospholipid syndrome; and P6, Takayasu arteritis. We used a training set of 151 clinical notes and an independent validation set of 256 clinical notes, with annotated phenotypes, both extracted from the Assistance Publique-Hôpitaux de Paris data warehouse. We evaluated the precision of the 3 patients closest to the index patient for each phenotype with precision-at-3 and recall and average precision. Results: For P1-P4, the precision-at-3 ranged from 0.85 (95% CI 0.75-0.95) to 0.99 (95% CI 0.98-1), the recall ranged from 0.53 (95% CI 0.50-0.55) to 0.83 (95% CI 0.81-0.84), and the average precision ranged from 0.58 (95% CI 0.54-0.62) to 0.88 (95% CI 0.85-0.90). P5-P6 phenotypes could not be analyzed due to the limited number of phenotypes. Conclusions: Using a method close to clinical reasoning, we built a scalable and interpretable end-to-end algorithm for extracting cohorts of similar patients. %M 36534446 %R 10.2196/42379 %U https://medinform.jmir.org/2022/12/e42379 %U https://doi.org/10.2196/42379 %U http://www.ncbi.nlm.nih.gov/pubmed/36534446