Head-to-head comparison of the CHOKAI and UROLITHIASIS scores for predicting ureteral stones: A multicenter prospective validation.

OBJECTIVE

The CHOKAI score, which includes seven clinical factors, namely, age, sex, pain features, hematuria, and hydronephrosis, was designed to predict uncomplicated renal colic and rule out serious alternative conditions. The more recently introduced UROLITHIASIS score adds laboratory data, such as urine microscopy and serum creatinine. This study compared the diagnostic accuracy of the CHOKAI and UROLITHIASIS scores for identifying ureteral stones and determined the optimal UROLITHIASIS cutoff in a Japanese cohort.

METHODS

We conducted a multicenter prospective observational study between May 2024 and June 2025, which involved 96 adults presenting with flank, back, or lower abdominal pain at nine Japanese hospitals. Both scores were calculated using clinical information, urinalysis, ultrasound, and blood tests. The final diagnoses were established via imaging and clinical evaluation. The primary outcome was the difference in the area under the receiver operating characteristic curve (AUC) between the two scores, whereas the secondary outcome was the optimal UROLITHIASIS cutoff value.

RESULTS

Of the 96 patients, 65 were diagnosed with ureteral stones. The CHOKAI score demonstrated better performance (AUC 0.941 [95 % CI, 0.877-0.995]) than the UROLITHIASIS score (AUC 0.853 [95 % CI, 0.758-0.937]) (P = 0.036). At its previously validated cutoff value ≥6, the CHOKAI score exhibited a sensitivity of 1.000 and a specificity of 0.793. The optimal cutoff value for the UROLITHIASIS score in this sample was ≥8.

CONCLUSIONS

The CHOKAI score exhibited higher diagnostic accuracy and maintained stronger performance at the validated threshold, which indicates its usefulness in avoiding unnecessary CT scans.