Rise in Emergency Department Visits of Pediatric Patients for Renal Colic from 1999-2008 John R. Allegra MD, PhD Morristown Memorial Residency in Emergency Medicine Emergency Medicine Associates of NJ Research Foundation

Authors Neeraja Kairam MD Barnet Eskin MD, PhD Morristown Memorial Hospital, Morristown, NJ Emergency Medical Research Associates Research Foundation

Introduction Renal colic is predominantly a disease of adults with only occasional cases occurring in the pediatric population. A recent report from a single hospital showed a rise in the number of children with renal colic.

Objectives To confirm in a large multihospital database whether there has been a rise in the number of emergency department visits for renal colic in the pediatric population.

Methods Design: Retrospective cohort. Setting: 29 EDs in New Jersey and New York, USA.

Population All emergency department pediatric patients ( age < 18 years) from 1-1-1999 to 12-31- 2008 with the ICD-9 diagnosis of “renal colic, calculus kidney, calculus ureter, urinary calculus, or uretheral calculus”

Protocol We analyzed the number of renal colic visits as a percent of the total emergency department pediatric visits in yearly intervals using the Student t test and performed a regression analysis. Alpha was set at 0.05.

Results The database contained 6.5 million visits of which 1.3 million (20%) were pediatric. 1028 (0.078%) visits were for renal colic Median age 16 yrs (IQR: 13-17 yrs) 61% were female.

Results The percentage of ED pediatric visits for renal colic increased from: 0.05% in 1999 to 0.089% in 2008 an increase of 78% (95% CI: 31-224%, p<0.003). The correlation coefficient for this upward trend was R2= 0.63 (p<0.007).

Discussion We found a marked increase in emergency department pediatric visits for renal colic over the past decade.

Discussion This may reflect a true rise in the incidence of renal colic in the pediatric population or may reflect an increased use of imaging modalities for abdominal and flank pain of uncertain etiology.

Limitations Our study is based on billing ICD 9 codes, which may be biased by physician’s habits with regard to assigning a diagnosis and coders’ assignment of ICD9 codes. There may also have been a drift in coding practices over the years.

Limitations We used as a denominator the total ED visits. Perhaps a better denominator would be population census data.

Limitations We did not have information on the severity of disease. Our cohort may have included many patients with mild disease.

Limitations The data here may not be representative of all hospital ED's, particularly those in the inner city and rural hospitals. The patterns may reflect the climate of New York and New Jersey and may not apply to other regions.

Conclusion We found a marked increase in emergency department pediatric visits for renal colic over the past decade.