Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Kidney stones are hard, pebble-like masses that form inside the kidney and can cause severe pain. When kidney stones are too large to pass out of the body in urine, patients may need treatment to remove them. As part of treatment, surgeons place long, hollow tubes called stents in the ureter to help drain urine from the kidney. But stents can cause pain and discomfort. Questions remain about which patients benefit from having a stent in place.

In this study, the research team is comparing patients with and without a stent to see how pain after treatment affects their daily lives. The team is also comparing patients’ unplanned healthcare use following treatment. 

Who can this research help?

Results may help doctors and patients when considering ways to treat kidney stones.

What is the research team doing?

The research team is enrolling 792 patients who are receiving surgery for kidney stones at one of 14 urology clinics across the United States. Before surgery, the team is asking patients if they agree to take part in a randomized controlled trial, or RCT. In RCTs, researchers assign patients to a treatment by chance. In this study, the treatment involves having a stent placed during surgery. In the group of patients who agree to take part in the RCT, the team is assigning patients by chance to have a stent placed or not.

The research team is asking patients who don’t agree to take part in the RCT if they are willing to take part in an observational study. In these studies, researchers examine what happens when patients and their doctors choose treatments. In the group of patients who agree to take part in the observational study, the surgeon is deciding whether to place a stent, which is usual clinical practice.

At the start of the study and again about one week and one month later, the research team is asking patients about:

  • How much their pain gets in the way of their daily activities
  • How intense their pain is
  • Urinary symptoms
  • Satisfaction with treatment

The research team is also asking patients and their caregivers about time off work during the first week after treatment. The team is looking at patients’ health records to track any unplanned healthcare use during the first month after treatment. Also, the team is interviewing 20–40 surgeons from the observational study. The team is asking surgeons why they decided to use a stent or not.

Patients who have had kidney stones and urologists are helping to plan and conduct this study.

Research methods at a glance

Design ElementDescription
DesignRandomized controlled trial 
Observational: cohort study
PopulationRandomized controlled trial: About 264 patients undergoing treatment for kidney stones 
Observational cohort study: About 528 patients undergoing treatment for kidney stones
  • Stent placement (randomized)
  • No stent placement (randomized)
  • Stent placement or no stent placement (nonrandomized; decided by surgeon)

Primary: pain interference; composite measure of healthcare utilization

Secondary: unplanned intensive care unit admissions, unplanned hospitalizations, unplanned additional procedures related to surgery, unplanned clinic visit and/or diagnostic testing, number of ambulatory patient–provider phone calls and/or electronic health record messages, pain intensity, urinary symptoms, treatment satisfaction, days of missed work among patients and caregivers

Timeframe  Timeframe Length of follow-up for collecting data on primary outcomes. View Glossary 1-month follow-up for primary outcomes

Project Information

Khurshid Ghani, MS
University of Michigan Medical School, Department
Stent Omission after Ureteroscopy and Lithotripsy in the Michigan Urological Surgery Improvement Collaborative (SOUL MUSIC)

Key Dates

July 2022
July 2025

Study Registration Information


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 26, 2024