External validation and comparison of two prediction models for seizure recurrence after the withdrawal of antiepileptic drugs in adult patients

Abstract Objective The models currently available for predicting the risk of seizure recurrence after antiepileptic drug (AED) withdrawal in adult epilepsy patients include the prediction model developed by Lamberink et al (Lamberink model, 2017) and the Medical Research Council prediction model (MRC model, 1993). However, there was no external validation for the two models. The purpose of this study was to perform an independent external validation and a comparison of the Lamberink model and the MRC model in adult patients. Methods The study population was recruited from the Wenzhou Epilepsy Follow‐up Registry Database (WEFURD). All the predictors of the Lamberink and MRC models and the occurrence of seizure recurrence in the participants were collected based on the WEFURD. Participants' predicted probabilities of seizure recurrence were obtained by a Web‐based tool and the prognostic index formula. The external validation of the Lamberink model and the MRC model were quantified by discrimination, calibration, and decision curve analysis (DCA). Results Of 212 patients, 126 (59.4%) had seizure recurrence after AED withdrawal. The Lamberink 2‐year model, the Lamberink 5‐year model, the MRC 1‐year model, and the MRC 2‐year model had areas under the curve of 0.71 (95% confidence interval [CI] = 0.64‐0.78), 0.68 (95% CI = 0.60‐0.76), 0.60 (95% CI = 0.50‐0.69), and 0.58 (95% CI = 0.50‐0.66), respectively. Additionally, the Lamberink 2‐year model had a significantly better integrated discrimination improvement than the MRC 2‐year model ( P < .001). Regarding calibration, the Lamberink 2‐year model ( P = .121) and the MRC 1‐year model ( P = .264) were well calibrated, but the Lamberink 5‐year model ( P = .022) and the MRC 2‐year model ( P = .008) were not. In the DCA, the Lamberink 2‐year model performed well at threshold probabilities of 30%‐65%. Significance This external validation shows that the Lamberink 2‐year model might be more accurate and has greater clinical benefit than others for guiding drug withdrawal in adult epilepsy clinics.