PREOP-gallstones: Surgeon Develops Prediction Model For Elective Gallbladder Removal

Taylor S. Riall, MD, PhD Professor, John Sealy Distinguished Chair in Clinical Research Department of Surgery, University of Texas Medical Branch, Galveston, Interview with:
Taylor S. Riall, MD, PhD

Professor, John Sealy Distinguished Chair in Clinical Research
Department of Surgery, University of Texas Medical Branch,
Galveston, TX

Medical Research: What is the background for this study? What are the main findings?

Dr. Riall: In patients who have symptoms related their gallstones – most commonly sharp right upper quadrant abdominal pain (often associated with fatty meals), nausea, and vomiting – the current recommendation is to remove the gallbladder (perform cholecystectomy). However, in older patients there are multiple factors that make this decision difficult. Older patients have more associated medical problems (like diabetes, heart disease, etc.) making elective surgery higher risk. On the flip side, older patients are at higher risk of developing complications from their gallstones, and once they do, their mortality (death from gallbladder disease) and complications increase substantially.

In recent study of Medicare beneficiaries with symptomatic gallstones, we found that fewer than 25% underwent elective removal of the gallbladder after an initial episode of pain or symptoms related to their gallbladder. We then developed a model that predicted the likelihood of these same patients requiring emergent gallstone-related complications if they did not have their gallbladder removed electively.

This information prompted the current study. We sought to determine if the patients getting their gallbladders removed were the ones at highest risk for complications. Similar to the previous study, we found that only 22% of Medicare beneficiaries in this study (a different population) underwent elective gallbladder removal. We divided patients into three groups based on our risk prediction model – those with <30% risk, 30-60% risk, and >60% risk of requiring acute gallstone-related hospitalization. Please note that while we call the <30% risk group “low” risk, a 17% chance of hospitalization is actually a significant risk – much higher than seen in other medical conditions for which surgery or other interventions may be considered.

  • First, our model worked well – the ACTUAL hospitalization rate was 17%, 45%, and 69% in the two years after the first symptoms.
  • Second, whether patients had their gallbladder removed seemed unrelated to risk. 22% of patients in the lowest risk group, 21% in the middle risk group, and 23% in highest risk group had their gallbladder removed. Even more striking, in the healthiest patients – those with no medical problems and no reason not to perform elective surgery – cholecystectomy rates actually decreased with increasing risk of emergent admission. Cholecystectomy was performed in 34% of patients in the low risk group, 25% of patients in the moderate risk group, and 26% of patients in the highest risk group.
  • In addition, fewer than 10% of patients who didn’t have their gallbladder removed were ever seen by a surgeon, suggesting that this decision is being made at the level of the primary care or emergency physician and not necessarily patient choice.

Medical Research: What should clinicians and patients take away from your report?

Dr. Riall: Treatment for any disease process, should, ideally be based on risk. In the era of patient-centered outcomes research, our risk prediction model, called PREOP-gallstones, provides a starting point for individualized care and shared decision making in older patients with gallstones. By using our model in clinical practice, especially at the level of the primary care physician, we can improve outcomes by increasing surgical referrals and elective cholecystectomy rates in older patients at highest risk for gallstone-related hospitalization. This would avoid the complications associated with subsequent complicated gallstone disease. Likewise, it would allow physicians to avoid cholecystectomy in patients who are high surgical risk and at low risk for developing complications from their gallstones. Finally, in patients who are low surgical risk and have low to moderate risk of complications, this risk information can help patients make a decision in the context of their symptoms, the impact of their symptoms on their quality of life, and their personal preferences.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Riall: Our next step is to perform in depth physician interviews to better understand how decisions regarding removal of the gallbladder are made. We are currently interviewing primary care physicians, emergency physicians, gastroenterologists and surgeons. Studies in other disease processes suggest that physicians are poor at predicting risk and incorporating this information into shared decision making. We are also interviewing patients to understand if they were offered surgery, if they were referred to a surgeon, and why, or why not, they chose to undergo cholecystectomy. Once we better understand the current decision making process

We are exploring the ideal way to incorporate our model into clinical practice such that is easy for physicians to use in their normal workflow. We will then perform studies evaluating the effectiveness of incorporating our model into clinical practice.


The Risk Paradox: Use of Elective Cholecystectomy in Older Patients Is Independent of Their Risk of Developing Complications
Riall, Taylor S. et al.

Journal of the American College of Surgeons
Published Online: December 17, 2014


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Last Updated on December 28, 2014 by Marie Benz MD FAAD