Abstract
OBJECTIVE AND RATIONALE: To investigate the longitudinal incidence of kidney/urinary stones in patients with severe motor and intellectual disabilities and explore health burden events in patients with stone formation. METHODS: This was a retrospective, observational study. We identified patients with severe motor and intellectual disabilities who had the following: 1) admission to our hospital wards for >10 years; 2) two or more assessments for stone formation by ultrasonography or computed tomography; and 3) absence of kidney/urinary stones in the first imaging study. The Kaplan-Meier method was used to analyze the cumulative incidence of kidney/urinary stones. Recurrent urinary tract infections, hydronephrosis, renal dysfunction, and death were identified as health burdens. RESULTS: Among the 41 patients (19 men, 22 women; median age, 28 years; range, 8-50 years), stone formation was detected in 11 (27%) patients during the observation period. The cumulative incidence rate of stone formation was 9.8% (95% confidence interval, 3.8-23.9) and 18.7% (95% confidence interval, 9.2-35.7) at five and 10 years, respectively. Death was frequently observed in patients with stone formation; six (55%) of the 11 patients with stone formation died during the follow-up period; two (15%) died among the other 30 patients without stone formation. However, only one patient with stone formation died in a renal event; the causal relationship between the stone formation and the deaths was not clarified. CONCLUSION: The longitudinal incidence of kidney/urinary stones was higher in patients with severe motor and intellectual disabilities than in the general population. Considering the difficulty of patients with severe motor and intellectual disabilities in conveying their symptoms, regular assessment of the kidney using abdominal imaging may be recommended.