External validation of an electronic health record-based diagnostic model for histological acute tubulointerstitial nephritis

Background
Accurate diagnosis of acute tubulointerstitial nephritis (AIN) often requires a kidney biopsy. We previously developed a diagnostic statistical model for predicting biopsy-confirmed AIN by combining four laboratory tests after evaluating over 150 potential predictors from the electronic health record. Here, we validate this diagnostic model in two biopsy-based cohorts at Johns Hopkins Hospital (JHH) and Yale, which were geographically and temporally distinct from the development cohort, respectively.
Methods
We analyzed patients who underwent kidney biopsy at JHH and Yale University (2019-2023). We assessed discrimination (AUC) and calibration using previously derived model coefficients and recalibrated the model using an intercept correction factor that accounted for differences in baseline prevalence of AIN between development and validation cohorts.
Results
We included 1982 participants: 1454 at JHH and 528 at Yale. JHH (5%) and Yale (17%) had lower proportions of biopsies..., , , # External validation of an electronic health record-based diagnostic model for histological acute tubulointerstitial nephritis

Please see accompanying manuscript for detailed methods: [https://pubmed.ncbi.nlm.nih.gov/39500309/](https://pubmed.ncbi.nlm.nih.gov/39500309/)

[https://doi.org/10.5061/dryad.3bk3j9kvf](https://doi.org/10.5061/dryad.3bk3j9kvf)

## Description of the data and file structure

Study design and participants: IRB-approved prospective study (HIC2000027890) enrolled participants who were scheduled to undergo a clinical kidney biopsy between July 2020 and June 2023 and consented to participate in the Yale Kidney Biobank (NCT04343417).

Data sources: We manually reviewed the electronic health record for clinician notes before the time of biopsy for pre-biopsy diagnosis. We classified the prebiopsy diagnosis as AIN if this was noted as a prebiopsy diagnosis in any position. In a sensitivity analysis at Yale, we classified the prebiopsy diagnosis as AIN only when this ...