Purpose: To characterize select laboratory tests ordered versus reported for patients diagnosed with COVID-19 in administrative healthcare and commercial laboratory data.
Methods: Among patients with an outpatient COVID-19 diagnosis claim in HealthVerity data (01/01/2021-12/31/2022), this study described baseline characteristics and descriptively compared SARS-CoV-2 diagnostic tests and liver function tests from administrative healthcare (insurance claims and hospital billing data) and commercial laboratories, overall and by code type (e.g., CPT, LOINC). Select liver function tests were also described by method-specific and methodless LOINC.
Results: Among 214 998 patients with COVID-19, 46.1% had a SARS-CoV-2 molecular diagnostic test recorded within 7 days of diagnosis (in either administrative or laboratory data); 44.5% had a corresponding CPT in medical claims, while only 10.0% had a corresponding LOINC in laboratory data. In contrast, the six most common liver function tests (albumin, aspartate aminotransferase, total protein, alkaline phosphatase, alanine aminotransferase, and total bilirubin) were identified in 55.7%-56.6% of patients via LOINC, but only in 3.2%-4.2% via CPT claims. Of the total count of select liver function tests performed in the laboratory data, 99.7% of aspartate aminotransferase, 96.1% of direct bilirubin, and 82.9% of lactate dehydrogenase were reported by methodless LOINC rather than method-specific LOINC.
Conclusions: Important differences were identified between orders for SARS-CoV-2 diagnostic tests and liver function tests, as well as missingness of LOINC method, highlighting challenges related to completeness of laboratory data in real-world data sources. These challenges underscore a need to improve data quality when considering the utility of laboratory data for research.
Keywords: COVID‐19; LOINC; SARS‐CoV‐2 tests; diagnostics; labs; liver function tests.
© 2025 John Wiley & Sons Ltd.