Development of a clinical prediction rule for determining the risk of upper urinary tract deterioration in patients with spinal cord injury

Objective: To develop the clinical prediction rule (CPR) of upper urinary tract deterioration (UUTD) outcome at three years, which is the average diagnostic timepoint, in patients with traumatic spinal cord injury (TSCI) Study design: Retrospective cohort study Setting: Department of Rehabilitation Medicine, Maharaj Nakorn Chiang Mai Hospital Subjects: TSCI patients with onset of injury in January 2008 - December 2020. Methods: After screening the medical records of 714 TSCI patients, clinical and urodynamic parameter data from 176 patients, collected at 3-18 months after SCI, were retrospectively analyzed. CPR was developed to predict UUTD at three years after SCI by conducting logistic regression analysis. The performance of the model was evaluated in terms of both discrimination and calibration using the AuROC and calibration plot, respectively. Results: The incidence of UUTD was 18.8% (33/176) with a mean duration of 3.72 years after the onset of injury. The developed CPR consists of three predictive factors: completeness of SCI (American Spinal Injury Association – ASIA Impairment Scale [AIS] C), presence of detrusor overactivity, and the occurrence of autonomic dysreflexia during a urodynamic study, to predict UUTD at three years after SCI. The developed CPR had acceptable discriminative (AuROC = 0.711 [95%CI:0.603-0.819] and calibrating performance (nearly approximate observed and predicted risk graphs and Brier Score = 0.1245). Conclusions: Our developed CPR for prognosing UUTD at three years after TSCI was established and demonstrated acceptable performance in both discrimination and calibration. However, a further external validation study is needed before applying this CPR in other clinical contexts.