Objective This study aimed to validate an osteoarthritis (OA) phenotyping algorithm within the Million Veteran Program (MVP) using the United States (US) Department of Veterans Affairs (VA) Centralized Interactive Phenomics Resource (CIPHER).

Methods A random sample of 213 veterans was analyzed sing ICD-9-CM/ICD-10-CM codes from a previously published algorithm (PMID:29559693). OA cases required two OA codes at least 30 days apart, while controls were excluded based on codes for conditions more common in OA patients, such as chondrocalcinosis and crystal arthropathies. Manual chart reviews identified documented OA mentions and joint replacements. Cohen’s kappa statistic assessed agreement. Discrepancies between chart data and coding were re-evaluated through re-abstraction.

Results Among 213 veterans, 174 (82%) had chart-documented OA. Agreement between chart review and code-based general OA identification was moderate (kappa = 0.47). Joint-specific agreement was substantial for knee (kappa = 0.63) and hip OA (kappa = 0.59), but lower for spine (kappa = 0.16) and hand (kappa = 0.34). Agreement was high for hip (kappa = 0.86) and knee replacements (kappa = 0.69). The McNemar test showed significant asymmetry for general OA, hand OA, and thumb OA, indicating discrepancies between chart and coded data. No significant asymmetry was found for knee and hip OA, supporting better alignment.

Conclusions This study supports the validity of the OA phenotyping algorithm using the VA database for identifying OA. The variability in identifying milder cases highlights the need for refined phenotyping algorithms and standardized diagnostic protocols to improve OA detection and personalized care for veterans.

JAS has received consultant fees from ROMTech; Atheneum; Clearview healthcare partners; American College of Rheumatology; Yale; Hulio; Horizon Pharmaceuticals/DINORA; ANI/Exeltis, USA Inc.; Frictionless Solutions; Schipher; Crealta/Horizon; Medisys; Fidia; PK Med; Two labs Inc.; Adept Field Solutions; Clinical Care options; Putnam associates; Focus forward; Navigant consulting; Spherix; MedIQ; Jupiter Life Science, UBM LLC; Trio Health; Medscape; WebMD; and Practice Point communications; the National Institutes of Health; and the American College of Rheumatology. JAS has received institutional research support from Zimmer Biomet Holdings. JAS received food and beverage payments from Intuitive Surgical Inc./Philips Electronics North America. JAS owns stock options in Atai life sciences; Kintara therapeutics; Intelligent Biosolutions; Acumen pharmaceutical; TPT Global Tech; Vaxart pharmaceuticals; Atyu biopharma; Adaptimmune Therapeutics; GeoVax Labs; Pieris Pharmaceuticals; Enzolytics Inc.; Seres Therapeutics; Tonix Pharmaceuticals Holding Corp.; Aebona Pharmaceuticals; and Charlotte's Web Holdings; Inc. JAS previously owned stock options in Amarin; Viking and Moderna pharmaceuticals. JAS is on the speaker's bureau of Simply Speaking. Dr. Singh was a member of the executive of Outcomes Measures in Rheumatology (OMERACT); an organization that develops outcome measures in rheumatology and receives arms-length funding from 8 companies. Dr. Singh serves on the FDA Arthritis Advisory Committee. Dr. Singh is the co-chair of the Veterans Affairs Rheumatology Field Advisory Board (FAB). Dr. Singh is the editor and the Director of the University of Alabama at Birmingham (UAB) Cochrane Musculoskeletal Group Satellite Center on Network Meta-analysis. Dr. Singh previously served as a member of the following committees: member; the American College of Rheumatology's (ACR) Annual Meeting Planning Committee (AMPC) and Quality of Care Committees; the Chair of the ACR Meet-the-Professor, Workshop and Study Group Subcommittee and the co-chair of the ACR Criteria and Response Criteria subcommittee. Other authors have no conflict of interest to disclose.

This research is based on data from the Million Veteran Program, Office of Research and Development, Veterans Health Administration, and was supported by MVP000, MVP078 as well as award #I01RX002745. This publication does not represent the views of the Department of Veteran Affairs or the United States Government.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

All participants were recruited as part of the MVP. All participants had previously consented to sharing their deidentified data for research. The research described in this manuscript received ethical and study protocol approval from the Veterans Affairs Central Institutional Review Board in accordance with the principles outlined in the Declaration of Helsinki.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

This study relied on the electronic health records housed in the VA medical system. All summary-level data produced in the present study are available upon reasonable request to the authors