Patient reports of pain cessation and stone passage do not always reflect true stone expulsion, according to study findings presented at the Canadian Urological Association 74th annual meeting in Quebec City.

In a large prospective study of 136 patients (69.5% male) with ureteral stones, radiographic imaging showed that only 58% of patients who reported pain cessation had actually passed their stones, Ryan McLarty, MD, of the University of Alberta in Edmonton, and colleagues reported. Furthermore, only 77.7% of patients claiming stone passage had in fact expelled their stones.

True ureteral stone passage was assessed by ultrasound, computed tomography, or ureteroscopy and compared with patient responses. Pain cessation had a high sensitivity (79.7%) but a low specificity (55.8%). Conversely, patient-reported stone passage had a high specificity (87.0%), but low sensitivity (59.3%).

“Both assessments may incorrectly assess ureteric stone expulsion,” Dr McLarty stated, “which raises concern for their validity as a clinical endpoint.”

Patients were followed for a mean 17 days from diagnosis. Half of cases involved distal ureteral stones. Mean stone size was 6.8 mm.

Reference

McLarty R, Assmus M, Wollin T, De S. Predicting ureteric stone expulsion with patient-reported outcomes: A prospective, observational study. Presented at the 2019 Canadian Urological Association 74th annual meeting held June 29-July 1 in Quebec City. Abstract POD-1.3.