The risk of renal calculi in spinal cord injury patients

A retrospective epidemiologic study of renal calculi was conducted on 5,915 patients from the National Spinal Cord Injury Data Research Center data base. Various risk factors suspected of contributing to the development of renal calculi were identified. Logistic regression analyses were conducted to estimate the adjusted odds ratio for the formation of renal calculi for each risk factor. Life-table techniques were used to assess the interval of highest renal stone risk after injury. Spinal cord injury patients in whom renal calculi developed were more likely to be male patients with neurologically complete lesions and histories of bladder stones. Renal stones were most likely to develop within 3 months after injury. The estimated cumulative proportion of patients free of renal stones 8 years after injury was 92 per cent. Although it appears that patients at high risk for renal calculi can be identified with a relatively small set of predictor variables, more definitive urological information is needed to improve predictive accuracy before final construction of mathematical predictive models that can be considered appropriate for use in a clinical environment.