In order to amalgamate these epidemiological data, the investigators used three primary sources: National Health and Nutrition Examination Survey data, Medicare data, and data from Optum. Medicare represents the more senior (≥65 years old) population, while Optum, which is an aggregate of data from private insurance companies, primarily represents the working-age population.
Not surprisingly, the prevalence of kidney stones continues to trend upwards according to both Medicare and Optum, and this trend is seen in both male and female populations, though men are more commonly affected (Figure 1). Similarly, the utilization of emergency medical services, as well as ambulatory visits for kidney stone disease, continue to rise. Among one of the most striking results from this study is the vast financial burden that stone disease creates. For example, Medicare data shows that costs for kidney stone disease exceeded $500 million in 2013 alone, with the majority of that cost coming from hospital outpatient services (Figure 2). Additionally, data illustrating the role that stone disease plays in the current “opioid crisis” in the United States is seen in the fact that opioids are the most commonly filled prescriptions for kidney stone patients, and this number was on an upward trajectory (Figure 3, red line).
Figure 1. Kidney stone prevalence (Medicare = top; Optum = bottom)
Figure 2. Kidney Stones - Service Expenditures (Medicare)
Figure 3. Kidney Stones - Filled Prescriptions (Medicare = top; Optum = bottom)
Regarding future directions, these data indicate that computed tomography (CT) imaging remains the mainstay of kidney stone evaluation, while ultrasound is relatively rarely used. With growing evidence of a role for ultrasound in kidney stone evaluation, Dr. Matlaga encouraged further investigation of this practice. He also acknowledged that, while his talk was high “United States-centric,” there are global implications to be gleaned from this study. In particular, the usefulness of Medicare in data tracking has implications for the potential to perform similar studies in countries that function largely under a single-payer system similar to Medicare.
Presented by: Brian Matlaga, MD, James Buchanan Brady Urological Institute, Johns Hopkins University
Written by: Frank Jefferson, Department of Urology, University of California-Irvine, medical writer for UroToday.com at the 36th World Congress of Endourology (WCE) and SWL - September 20-23, 2018 Paris, France