ArticleAnnals of epidemiology2025
Quantifying the primary care workforce in the U.S.: A validation study with and without an imperfectly measured referent standard.
Article in Annals of epidemiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
1 citing paper in PubMed.
- Primary care workforce structural inertia and Medicaid participation during the COVID-19 pandemic, 2020-2021.Health affairs scholar · 2026Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
purposeTo validate the National Provider Identifier (NPI), a commonly used data source in health services research, for identifying primary care physicians, physician assistants (PAs), and nurse practitioners (NPs).
methodsValidation studies to calculate the sensitivity, specificity, and associated 95 % confidence intervals for physicians, PAs, and NPs. For physicians, Medicare claims data were used as an imperfectly measured referent standard. For PAs and NPs, we used a simulation-based method to estimate accuracy parameters that assumed the NPI and Medicare claims were equally misclassified.
resultsUsing the Medicare claims as the referent standard for physicians yielded a sensitivity and specificity of 0.95 (95 % CI: 0.88, 0.98) and 0.76 (95 % CI: 0.73, 0.79), respectively. Using the simulation-based method yielded a sensitivity and specificity of 0.57 (95 % CrI: 0.11, 0.97) and 0.56 (95 % CrI: 0.10, 0.96), respectively for PAs and 0.58 (95 % CrI: 0.13, 0.97) and 0.61 (95 % CrI: 0.14, 0.97), respectively for NPs.
conclusionsOur validation results varied by provider role. Accuracy was highest for physicians further highlighting the challenges in quantifying PAs and NPs based on their NPI alone. Failure to consider potential misclassification in the NPI may result in biased research findings.
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