PS2-22: Accuracy of Diagnostic Codes to Identify Rheumatoid Arthritis in Archived Electronic Health System Data: Support for Future Cancer Research Network Studies of Lymphoma Risk Pathways
Year: 2013
Type: article
Abstract: Background/Aims: In preliminary work toward Cancer Research Networkbased studies of lymphoma risk pathways, we undertook an evaluation of the utility of ICD-9 CM diagnostic codes to accurately identify potential risk factor conditions, including rheumatoid arthritis (RA).Methods: Using the enrolled Virtual Data Warehouse (VDW) cohort at Marshfield Clinic Research Foundation, we ascertained a set of potential RA cases diagnosed between 2000 and 2010 by the presence of one or more diagnostic codes for RA (ICD-9 CM 714-714.89).Medical records were abstracted by trained staff on a random sample of 206 cases.Cases were adjudicated into categories of confirmed, probable, documented physician diagnosis only, equivocal, and non-case using a literature-based gold standard definition scheme.Outcome measures included positive predictive value (PPV) and relative sensitivity, with the confirmed, probable and physician diagnosis categories considered valid cases for the main analysis.Results: Upon review, 25 subjects did not have sufficient medical records available for evaluation, leaving 181 subjects for analysis, including 57 with only one RA code and 124 with 2 or more instances of an RA code.Overall PPV for patients with one or more RA codes was 56%.Subjects with only one diagnostic code had very low PPV (12%), while PPV was higher among those with 2 or more (76%).PPV improved to 91% when requiring a rheumatologist diagnosis, but only 40% of the true cases in the set were detectable in this way.The one algorithm that provided acceptably high PPV and relative sensitivity required 2 or more RA diagnostic codes and history of a rheumatoid factor test (PPV 83%, relative sensitivity 82%).Conclusions: A single ICD-9CM diagnostic code for RA was not highly predictive of a true diagnosis, but PPV was enhanced when requiring multiple codes and incorporating other VDW data elements.With one exception, algorithms with higher PPV had strong reductions in relative sensitivity.Limitations include non-systematic collection of RA medication data preventing the use of treatment in the algorithms, and the inability to evaluate absolute sensitivity.Next steps include a joint RA analysis with investigators at Kaiser Permanente Southern California, and possible inclusion of RA treatment data into the Marshfield algorithms.
Source: Clinical Medicine & Research
Institutions: Marshfield Clinic, National Cancer Institute
Language: English
Subfield: Health Information Management
Field: Health Professions
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2155967247