Trend of Incident Kidney Stone Disease in a Large Managed Care Organization 1997-2007

Objective: Recent trend of incident kidney stone disease in the U.S. population is not clear. We aim to determine the incidence trend through time in an integrated healthcare system serving a defined geographical region. Methods: Incident kidney stone rates were obtained using the Intermountain Healthcare Data Warehouse. Intermountain Healthcare is a healthcare organization that serves over 2 million Utah residents. Incident stone formers were defined as patients having first ever diagnosis of kidney stone disease and were identified by ICD9 codes 592.0, 592.1 & 592.9 assigned from 1997 to 2007. Negative binomial regression analyses were used to examine the incidence trend. Results: 53,045 incident stone formers were identified. Adjusted for age, gender, race and imaging use, there were no significant changes in kidney stone incidence rates from 1997 (0.49%) to 2007 (0.52%), p=0.2. For men, the age, race and imaging use adjusted incidence rates were stable from 1997 (0.67%) to 2007 (0.63%), p=0.9. For women, the adjusted incidence rates also did not change significantly from 1997 (0.35%) to 2007 (0.44%), p=0.3. Furthermore, the age, gender and imaging use adjusted incident rates did not change significantly in any of the race categories (non-Hispanic white, non-Hispanic black and Mexican Americans) from 1997 to 2007. Conclusions: Incident kidney stone rates did not change from 1997 to 2007 in our study population from Utah. The causes of these findings remain to be determined.