NCT07718802 · Children's Hospital of Philadelphia
Observational Approach Versus Surgical Intervention for Stones
(OASIS)
What this study is about
The aims of the Observational Approach versus Surgical Intervention for Asymptomatic Stone (OASIS) trial are: 1) to determine whether observation compared to upfront surgery results in less healthcare-related life disruption due to kidney stones among children and adults with asymptomatic kidney stones; 2) to identify the groups benefiting the most from each strategy; and 3) to determine the preferences and values informing the choice between observation and upfront surgery.
View original scientific description
The aims of the Observational Approach versus Surgical Intervention for Asymptomatic Stone (OASIS) trial are: 1) to determine whether observation compared to upfront surgery results in less healthcare-related life disruption due to kidney stones among children and adults with asymptomatic kidney stones; 2) to identify the groups benefiting the most from each strategy; and 3) to determine the preferences and values informing the choice between observation and upfront surgery.
Interventions
PROCEDURE
Surgery
Upfront surgery is the planned removal of asymptomatic stones and includes ureteroscopy and shockwave lithotripsy, which are routinely used in standard clinical care.
OTHER
Observation
Observation is the surveillance of asymptomatic stones with periodic CT, ultrasound, or x-ray, and clinic visits.
Primary outcome measures
Healthcare-related life disruption
Time frame: Every 3 months (+/- 14 days) from date of consent (observational cohort) or randomization (randomized cohort) until 24 months.
Composite of: Stone-specific emergency department (ED)/urgent care visits, stone-specific hospitalizations and surgery for stones for new symptoms (Shockwave Lithotripsy (SWL) and Ureteroscopy (URS)) as reported via Patient Centered Outcomes Research Network (PCORnet) Common Data Model (CDM) query and participant self-report on REDCap.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Individuals age 6 or older
- Diagnosis of kidney stone disease (nephrolithiasis)
- Asymptomatic, non-obstructive kidney stones measuring 4 to 10 mm (inclusive)
- Asymptomatic is defined as the absence of abdominal pain, flank pain, gross hematuria, and nausea and/or vomiting in the last 3 months that in the judgement of the site PI could be attributable to kidney stones.
- Non-obstructive is defined as a stone in a renal calyx or stones in multiple renal calyces on CT, ultrasound, and/or x-ray obtained within 6 months of screening.
- Informed consent and if appropriate, child assent.
- Willingness to be randomized to surgery or observation Note: subjects otherwise eligible who decline randomization may be enrolled in a parallel observational cohort.
- Fluent in English or Spanish
- Willingness to be audio- and/or video- recorded during interviews
Exclusion criteria
- Untreated hydronephrosis or caliectasis
- Pain (e.g., renal colic, abdominal pain) or gross hematuria attributed to kidney stones.
- Recurrent symptomatic urinary tract infections (≥3 in 12 months or ≥2 in 6 months). A symptomatic urinary tract infection is defined as having at least one bladder or voiding symptom (e.g., frequency, urgency, dysuria) with bacteriuria (≥105 colony forming units/mL of no more than 2 urinary tract pathogens).
- Stone in the renal pelvis, ureter, bladder or urethra
- Pregnant females
- Solitary kidney, transplant kidney, urinary diversion, medullary sponge kidney
- Anatomic abnormality of the kidney (e.g., horseshoe kidney)
- Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures
Where
- Minneapolis, Minnesota
- Philadelphia, Pennsylvania
Collaborators
Patient-Centered Outcomes Research Institute
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 3, 2026 · Source of record for eligibility and locations