Moledina, Dennis G.Eadon, Michael T.Calderon, FridaYamamoto, YuShaw, MelissaPerazella, Mark A.Simonov, MichaelLuciano, RandySchwantes-An, Tae-HwiMoeckel, GilbertKashgarian, MichaelKuperman, MichaelObeid, WassimCantley, Lloyd G.Parikh, Chirag R.Wilson, F. Perry2023-10-112023-10-112022Moledina DG, Eadon MT, Calderon F, et al. Development and external validation of a diagnostic model for biopsy-proven acute interstitial nephritis using electronic health record data [published correction appears in Nephrol Dial Transplant. 2023 Aug 31;38(9):2098]. Nephrol Dial Transplant. 2022;37(11):2214-2222. doi:10.1093/ndt/gfab346https://hdl.handle.net/1805/36259Background: Patients with acute interstitial nephritis (AIN) can present without typical clinical features, leading to a delay in diagnosis and treatment. We therefore developed and validated a diagnostic model to identify patients at risk of AIN using variables from the electronic health record. Methods: In patients who underwent a kidney biopsy at Yale University between 2013 and 2018, we tested the association of >150 variables with AIN, including demographics, comorbidities, vital signs and laboratory tests (training set 70%). We used least absolute shrinkage and selection operator methodology to select prebiopsy features associated with AIN. We performed area under the receiver operating characteristics curve (AUC) analysis with internal (held-out test set 30%) and external validation (Biopsy Biobank Cohort of Indiana). We tested the change in model performance after the addition of urine biomarkers in the Yale AIN study. Results: We included 393 patients (AIN 22%) in the training set, 158 patients (AIN 27%) in the test set, 1118 patients (AIN 11%) in the validation set and 265 patients (AIN 11%) in the Yale AIN study. Variables in the selected model included serum creatinine {adjusted odds ratio [aOR] 2.31 [95% confidence interval (CI) 1.42-3.76]}, blood urea nitrogen:creatinine ratio [aOR 0.40 (95% CI 0.20-0.78)] and urine dipstick specific gravity [aOR 0.95 (95% CI 0.91-0.99)] and protein [aOR 0.39 (95% CI 0.23-0.68)]. This model showed an AUC of 0.73 (95% CI 0.64-0.81) in the test set, which was similar to the AUC in the external validation cohort [0.74 (95% CI 0.69-0.79)]. The AUC improved to 0.84 (95% CI 0.76-0.91) upon the addition of urine interleukin-9 and tumor necrosis factor-α. Conclusions: We developed and validated a statistical model that showed a modest AUC for AIN diagnosis, which improved upon the addition of urine biomarkers. Future studies could evaluate this model and biomarkers to identify unrecognized cases of AIN.en-USPublisher PolicyBiopsyCreatinineElectronic health recordInterstitial nephritisUrinalysisArticle