Source of Funding: None

643A COMPARISON OF INPATIENT VERSUS OUTPATIENTRESISTANCE PATTERNS IN PEDIATRIC URINARYTRACT INFECTION

Kara N. Saperston*, San Francisco, CA; Dan J. Shapiro, SanFrancisco, CO; Adam L. Hersh, Salt Lake City, UT; Hillary L. Copp,San Francisco, CA

INTRODUCTION AND OBJECTIVES: Most antibiograms foruropathogens are derived from hospital-based laboratory data. There isevidence that these data may provide inaccurate information aboutambulatory uropathogen resistance patterns. The goal of the presentstudy was to compare current national patterns of inpatient and outpa-tient antibiotic resistance in pediatric UTI.

METHODS: We examined inpatient and outpatient urinary iso-lates from children �18 years using The Surveillance Network®(TSN®), a database with antibiotic susceptibility results and patientdemographic data from 195 US hospitals. We determined the preva-lence and antibiotic resistance patterns for the six most commonuropathogens: Escherichia coli, Proteus mirabilis, Klebsiella, Entero-bacter, Pseudomonas aeruginosa, and Enterococcus. We compareddifferences in uropathogen prevalence and resistance patterns forinpatient and outpatient isolates with chi-square analysis.

RESULTS: We identified 25,418 outpatient (86% female) and5560 inpatient (63% female) urinary isolates. Escherichia coli was themost common uropathogen overall, but the prevalence of Escherichiacoli varied by sex and visit setting: outpatient isolates (79% of uropatho-gens overall: females 83%, males 50%) versus inpatient isolates (54%overall: females 64%, males 37%) (p�0.001). Resistance rates formany commonly prescribed antibiotics were higher in the inpatientversus outpatient setting: Escherichia coli: TMP/SMX (30% vs. 24%)and cephalothin (22% vs. 16%) (p�0.001); Klebsiella: cephalothin(14% vs. 7%) (p�0.03); Enterobacter: ceftriaxone (24% vs. 12%) andceftazidime (33% vs. 15%) (p�0.001); Enterococcus: ampicillin (13%vs. 3%) and ciprofloxacin (12% vs. 5%) (p�0.001). Resistance ratesbetween Proteus and Pseudomonas were similar between inpatientand outpatient isolates.

CONCLUSIONS: Uropathogen resistance rates for several ofthe most common antibiotic agents are substantially higher for urinaryspecimens obtained from inpatients than from outpatients. Separatehospital- and community-based antibiograms should be performed tooptimize empiric-prescribing choices for UTI in children.

Prevalence of uropathogen by sex and visit setting

Organism

Mal

eO

utpt

Pre

vale

nce

Mal

eIn

ptP

reva

lenc

e

P-v

alue

Fem

ale

Out

ptP

reva

lenc

e

Fem

ale

InP

tP

reva

lenc

e

P-v

alue

E. Coli50%

(48–52)37%

(35–39) �0.00183%

(83–84)64%

(63–66) �0.001

Enterobacter5%

(5–6)10%

(8–11) �0.0011%

(1–1)4%

(4–5) �0.001

Enterococcus17%

(16–18)27%

(25–29) �0.0015%

(5–5)13%

(12–14) �0.001

Klebsiella10%

(9–11)12%

(10–13) 0.074%

(4–5)10%

(9–11) �0.001

P. aeruginosa7%

(6–8)10%

(8–11) �0.0012%

(2–2)6%

(5–7) �0.001

P. mirabilis11%

(10–12)5%

(4–6) �0.0014%

(4–4)2%

(2–3) �0.001

No. of observ. 3,437 2,072 21,981 3,488

Source of Funding: None

644RELIABILITY OF VOIDING CYSTOURETHROGRAM FOR THEGRADING OF VESICOURETERAL REFLUX

O’Neil Brock*, Patrick Cartwright, Constance Maves, Karin Hoeg,Angela Presson, Chad Wallis, Salt Lake City, UT

INTRODUCTION AND OBJECTIVES: The voiding cystoure-throgram (VCUG) is commonly used in the evaluation of urinary tractinfections and in the setting of hydronephrosis to detect vesicoureteralreflux (VUR). It is important to understand differences in VCUG gradingbetween interpreting physicians as pediatricians depend heavily uponradiologists’ reports for management and referral decisions while pe-diatric urologists base treatment on their own interpretation. Further,understanding VCUG reliability will better frame VUR research resultsas many studies utilize VCUG grading for participant entry and treat-ment protocols. We sought to assess the reliability of VCUG betweenand among pediatric radiologists and urologists.

METHODS: Two-hundred consecutive VCUGs representing400 renal units were independently graded by two fellowship trainedpediatric urologists and pediatric radiologists. VUR was graded from 0to V according to the International Classification of VesicoureteralReflux. Studies were excluded if ordered primarily for neurogenicbladder or posterior urethral valves. A quadratic weighted kappa coef-ficient was calculated to determine inter-rater agreement where valuesbetween 0.81-1 were considered near perfect agreement. A modifiedMcNemar test was performed to assess for systematic rater bias with0.5 indicating no bias.

RESULTS: Seventy-five percent of studies are in female chil-dren with a mean age of 4.54 months (SD 3.72). Weighted kappavalues reflect very strong reliability of VCUG for grading VUR between(0.95) and among urologists (0.97) and radiologists (0.95). Closerinspection of scoring reveals important discrepancies in grading clus-tered around grades II-IV with raters assigning different scores in up to49% of cases. There is also significant bias with radiologists reportinghigher grades (McNemar ratio 0.88; p�0.0001).

CONCLUSIONS: VCUG is very reliable for grading VUR. Ra-diologists may grade reflux higher than urologists. This propensity islikely advantageous as a higher grade is more likely to result in areferral by primary care providers to a pediatric urologist than if radiol-ogists were biased to grade lower. Disagreement between raters is notan uncommon event but differences are generally only by a singlegrade leading to high kappa values. However, scoring discrepanciesare more common with certain grades (II-IV) and even small differ-ences in this critical range may result in important alterations to clinicaldecisions and interpretation of research results that rely on the VCUGfor patient stratification.

Source of Funding: None

Vol. 189, No. 4S, Supplement, Sunday, May 5, 2013 THE JOURNAL OF UROLOGY� e263