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Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Potential misclassification of patients with psoriasis in electronic databases
Murat Icen1, Cynthia S Crowson, Marian T McEvoy
1Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Journal of the American Academy of Dermatology
|October 7, 2008
Summary
Electronic health record psoriasis diagnostic codes have limited accuracy for research. Manual review confirmed psoriasis in only 57% of patients identified by codes, highlighting potential misclassification in studies.
Area of Science:
- Dermatology
- Health Informatics
- Epidemiology
Background:
- Electronic health records (EHRs) and claims databases are vital for observational research.
- Psoriasis diagnosis validation in EHRs is crucial for accurate study outcomes.
Purpose of the Study:
- To assess the accuracy of psoriasis diagnostic codes within an electronic database.
- To determine the positive predictive value of these codes for identifying psoriasis patients.
Main Methods:
- A population-based study in Olmsted County, Minnesota, utilizing a comprehensive electronic database.
- Manual review of medical records for 2556 patients with psoriasis-related diagnostic codes (1976-2000).
Main Results:
- Psoriasis was confirmed in 57.0% of patients (1458/2556), with 81% confirmed by dermatologists.
- The most common code, ICD-9 696.1, had a positive predictive value of 68.7%.
- Increased code frequency improved predictive value, but a single code in 5 years still yielded 60% accuracy.
Conclusions:
- Electronic identification of psoriasis patients using diagnostic codes alone risks misclassification.
- The variable nature of psoriasis (remitting/relapsing, diverse presentation) complicates accurate case ascertainment in databases.
