{"doi":"10.1093/schbul/sbae064","title":"Validation of an ICD-Code-Based Case Definition for Psychotic Illness Across Three Health Systems","abstract":"BACKGROUND AND HYPOTHESIS: Psychosis-associated diagnostic codes are increasingly being utilized as case definitions for electronic health record (EHR)-based algorithms to predict and detect psychosis. However, data on the validity of psychosis-related diagnostic codes is limited. We evaluated the positive predictive value (PPV) of International Classification of Diseases (ICD) codes for psychosis. STUDY DESIGN: Using EHRs at 3 health systems, ICD codes comprising primary psychotic disorders and mood disorders with psychosis were grouped into 5 higher-order groups. 1133 records were sampled for chart review using the full EHR. PPVs (the probability of chart-confirmed psychosis given ICD psychosis codes) were calculated across multiple treatment settings. STUDY RESULTS: PPVs across all diagnostic groups and hospital systems exceeded 70%: Mass General Brigham 0.72 [95% CI 0.68-0.77], Boston Children's Hospital 0.80 [0.75-0.84], and Boston Medical Center 0.83 [0.79-0.86]. Schizoaffective disorder PPVs were consistently the highest across sites (0.80-0.92) and major depressive disorder with psychosis were the most variable (0.57-0.79). To determine if the first documented code captured first-episode psychosis (FEP), we excluded cases with prior chart evidence of a diagnosis of or treatment for a psychotic illness, yielding substantially lower PPVs (0.08-0.62). CONCLUSIONS: We found that the first documented psychosis diagnostic code accurately captured true episodes of psychosis but was a poor index of FEP. These data have important implications for the case definitions used in the development of risk prediction models designed to predict or detect undiagnosed psychosis.","journal":"Schizophrenia Bulletin","year":2024,"id":448628,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":5,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9223,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":274491,"name":"Víctor M. Castro","orcid":"0000-0001-7390-6354","position":1,"is_corresponding":false},{"id":1267566,"name":"Ashley Baker","orcid":"0000-0002-6525-7013","position":2,"is_corresponding":false},{"id":748602,"name":"Devon Carroll","orcid":"0000-0002-1673-8865","position":3,"is_corresponding":false},{"id":736493,"name":"Joseph Gonzalez–Heydrich","orcid":"0000-0002-3073-983X","position":4,"is_corresponding":false},{"id":302332,"name":"David C. Henderson","orcid":"0000-0001-8755-4505","position":5,"is_corresponding":false},{"id":371941,"name":"Daphne J. Holt","orcid":"0000-0002-6428-9603","position":6,"is_corresponding":false},{"id":1090607,"name":"Kimberly Hook","orcid":"0000-0003-1027-5449","position":7,"is_corresponding":false},{"id":297356,"name":"Rakesh Karmacharya","orcid":"0000-0002-0565-5482","position":8,"is_corresponding":false},{"id":471928,"name":"Joshua L. Roffman","orcid":"0000-0003-4073-532X","position":9,"is_corresponding":false},{"id":1268016,"name":"Emily M Madsen","orcid":null,"position":10,"is_corresponding":false},{"id":1267567,"name":"Eugene Song","orcid":"0000-0002-8785-7562","position":11,"is_corresponding":false},{"id":274493,"name":"William G. Adams","orcid":"0000-0002-5330-0010","position":12,"is_corresponding":false},{"id":333647,"name":"Luísa Camacho","orcid":"0000-0002-3300-3895","position":13,"is_corresponding":false},{"id":1268017,"name":"Sarah Gasman","orcid":null,"position":14,"is_corresponding":false},{"id":1268018,"name":"Jada S. Gibbs","orcid":null,"position":15,"is_corresponding":false},{"id":667981,"name":"Rebecca G. Fortgang","orcid":"0000-0001-5388-3386","position":16,"is_corresponding":false},{"id":251911,"name":"Chris J. Kennedy","orcid":"0000-0001-7444-2766","position":17,"is_corresponding":false},{"id":1268019,"name":"Galina Lozinski","orcid":null,"position":18,"is_corresponding":false},{"id":1267568,"name":"Daisy C. Perez","orcid":"0000-0002-9528-0062","position":19,"is_corresponding":false},{"id":868525,"name":"Marina Wilson","orcid":"0009-0001-0867-7599","position":20,"is_corresponding":false},{"id":39622,"name":"Ben Y. Reis","orcid":"0000-0001-9908-5523","position":21,"is_corresponding":false},{"id":104618,"name":"Jordan W. Smoller","orcid":"0000-0002-0381-6334","position":22,"is_corresponding":false},{"id":56252,"name":"Anthony J. Deo","orcid":null,"position":0,"is_corresponding":true}],"reference_count":16,"raw_metadata":null,"created_at":"2026-07-19T02:02:12.215092Z","pmid":"38728421","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}