Technical Report-Diagnosis and Management of an Initial UTI in Febrile Infants and Young Children
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FROM THE AMERICAN ACADEMY OF PEDIATRICS Technical Report—Diagnosis and Management of an Initial UTI in Febrile Infants and Young Children S. Maria E. Finnell, MD, MS, Aaron E. Carroll, MD, MS, Stephen M. Downs, MD, MS, and the Subcommittee on Urinary Tract Infection abstract OBJECTIVES: The diagnosis and management of urinary tract infec- KEY WORDS urinary tract infection, infants, children, vesicoureteral reflux, tions (UTIs) in young children are clinically challenging. This report was voiding cystourethrography, antimicrobial, prophylaxis, developed to inform the revised, evidence-based, clinical guideline re- antibiotic prophylaxis, pyelonephritis garding the diagnosis and management of initial UTIs in febrile infants ABBREVIATIONS and young children, 2 to 24 months of age, from the American Academy UTI—urinary tract infection of Pediatrics Subcommittee on Urinary Tract Infection. VUR—vesicoureteral reflux VCUG—voiding cystourethrography METHODS: The conceptual model presented in the 1999 technical re- CI—confidence interval port was updated after a comprehensive review of published litera- RR—risk ratio RCT—randomized controlled trial ture. Studies with potentially new information or with evidence that LR—likelihood ratio reinforced the 1999 technical report were retained. Meta-analyses on SPA—suprapubic aspiration the effectiveness of antimicrobial prophylaxis to prevent recurrent UTI This document is copyrighted and is property of the American were performed. Academy of Pediatrics and its Board of Directors. All authors have filed conflict of interest statements with the American RESULTS: Review of recent literature revealed new evidence in the Academy of Pediatrics. Any conflicts have been resolved through following areas. Certain clinical findings and new urinalysis methods a process approved by the Board of Directors. The American can help clinicians identify febrile children at very low risk of UTI. Oral Academy of Pediatrics has neither solicited nor accepted any commercial involvement in the development of the content of antimicrobial therapy is as effective as parenteral therapy in treating this publication. UTI. Data from published, randomized controlled trials do not support The guidance in this report does not indicate an exclusive antimicrobial prophylaxis to prevent febrile UTI when vesicoureteral course of treatment or serve as a standard of medical care. reflux is found through voiding cystourethrography. Ultrasonography Variations, taking into account individual circumstances, may be of the urinary tract after the first UTI has poor sensitivity. Early antimi- appropriate. crobial treatment may decrease the risk of renal damage from UTI. CONCLUSIONS: Recent literature agrees with most of the evidence presented in the 1999 technical report, but meta-analyses of data from recent, randomized controlled trials do not support antimicrobial pro- phylaxis to prevent febrile UTI. This finding argues against voiding cys- tourethrography after the first UTI. Pediatrics 2011;128:e749–e770 www.pediatrics.org/cgi/doi/10.1542/peds.2011-1332 doi:10.1542/peds.2011-1332 All technical reports from the American Academy of Pediatrics automatically expire 5 years after publication unless reaffirmed, revised, or retired at or before that time. PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275). Copyright © 2011 by the American Academy of Pediatrics COMPANION PAPERS: Companions to this article can be found on pages 572 and 595, and online at www.pediatrics.org/cgi/doi/ 10.1542/peds.2011-1330, www.pediatrics.org/cgi/doi/10.1542/ peds.2011-1818, and www.pediatrics.org/cgi/doi/10.1542/peds. 2011-1330. PEDIATRICS Volume 128, Number 3, September 2011 e749 Downloaded from by guest on November 1, 2015
FIGURE 1 Evidence model from the 1999 technical report on the diagnosis and treatment of infants and children with UTIs. In 1999, the Subcommittee on Urinary nician must undertake a diagnostic was considered very poor, and the ef- Tract Infection of the American Acad- strategy, primarily involving labora- fectiveness of treatments to prevent emy of Pediatrics released its guide- tory testing, to arrive at a posterior these complications was not ad- line on detection, diagnosis, and man- (posttest) probability of UTI, ruling the dressed directly but was assumed. agement for children between 2 and 24 diagnosis in or out. Poor test choices The cost-effectiveness analysis using months of age with febrile urinary or interpretation of results can lead to these data led to the conclusion that tract infections (UTIs).1 The guideline misdiagnosis. In cell 3, the clinician diagnosis and treatment of UTI and was supported by a technical report2 must choose a treatment for acute UTI; evaluation for urinary tract anomalies that included a critical review of the in cell 4, the clinician must consider had borderline cost-effectiveness, relevant literature and a cost- the possibility of structural or func- costing approximately $700 000 per effectiveness analysis. Consistent with tional anomalies of the urinary tract case of hypertension or end-stage re- the policies of the American Academy and diagnose them appropriately to nal disease prevented. On the basis of of Pediatrics, the subcommittee has avoid ongoing renal damage. these results, the subcommittee rec- undertaken a revision of the guideline. Implicit in cell 4 is the idea that anom- ommended testing all children be- This technical report was developed to alies of the urinary tract, such as vesi- tween 2 and 24 months of age with fe- support the guideline.3 coureteral reflux (VUR) and obstruc- ver with no obvious source for UTI, by The revised technical report was to be tions, may, if left untreated, lead to culturing urine obtained through blad- based on a selective review of the liter- significant renal damage, resulting in der tap or catheterization. As an option ature, focusing on changes in the evi- hypertension or end-stage renal dis- for children who were not going to re- dence regarding detection, diagnosis, ease. Furthermore, it is assumed that ceive immediate antimicrobial treat- and management of UTIs in these chil- treatment with medical or surgical ment, the committee recommended dren. The original technical report was therapies can prevent these conse- ruling out UTI through urinalysis of designed around an evidence model quences successfully. urine obtained with any convenient (Fig 1). Each cell (numbered 1– 4) cor- The conclusions of the 1999 technical method. The committee concluded that responded to a stage in the recogni- report were that there were high- children found to have a UTI should un- tion, diagnosis, or management of UTI. quality data regarding the prevalence dergo renal ultrasonography and void- The boxes represented steps the clini- of UTI among febrile infants, the per- ing cystourethrography (VCUG) for cian must follow, and the arrows rep- formance of standard diagnostic tests evaluation for urinary tract abnormal- resented the process of moving from for UTI, and the prevalence of urinary ities, most frequently VUR. one step to the next. Downward arrows tract abnormalities among children Ten years later, the subcommittee has represented undesirable consequences with UTI. The evidence indicating that undertaken a review of the technical in management.4 certain patient characteristics (age, analysis for a revised guideline. The In cell 1, the clinician must combine gender, and circumcision status) af- strategy for this technical report was patient demographic data and other fected the probability of UTI was to survey the medical literature pub- presenting clinical data to arrive at an weaker. The evidence supporting the lished in the past 10 years for studies assessment of the risk of UTI. Failure to relationship between urinary tract ab- of UTIs in young children. The literature do so results in a missed opportunity normalities and future complications, was examined for any data that varied to make the diagnosis. In cell 2, the cli- such as hypertension or renal failure, significantly from those analyzed in the e750 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS first technical report. This survey children with VUR. To explore this par- asymptomatic bacteriuria in addition found an emerging body of literature ticular issue, a second, systematic, tar- to the cases of pyelonephritis or fe- addressing the effectiveness of antimi- geted literature search and formal brile UTI. crobial agents to prevent recurrent meta-analysis were conducted to esti- UTI. Therefore, the authors conducted mate the effectiveness of antimicro- Search Methods a critical literature review and meta- bial prophylaxis to prevent renal dam- The initial literature search was con- analysis focused on that specific issue. age in children with VUR. In addition, 1 ducted on June 24, 2008, and the author (Dr Finnell) and the chairper- search was repeated on April 14, 2009. METHODS son of the guideline committee (Dr Studies were obtained from the follow- Surveillance of Recent Literature Roberts) contacted the authors of ing databases: Medline (1993 to June those studies to obtain original data 2008), Embase (1993 to June 2008), Co- The authors searched Medline for arti- permitting subgroup analyses. chrane Central Register for Controlled cles published in the past 10 years with the medical subject headings Trials, bibliographies of identified rel- Targeted Literature Search and “urinary tract infection” and “child evant articles and reviews, and the Meta-analysis (all).” The original search was con- Web site www.ClinicalTrials.gov. To examine specifically the effective- ducted in 2007, but searches were re- The search terms “vesico-ureteral re- ness of antimicrobial prophylaxis to peated at intervals (approximately ev- flux,” “VUR,” “vesicoureter*,” “vesico prevent recurrent UTI and pyelone- ery 3 months) to identify new reports ureter*,” “vesicourethral,” or “vesico phritis in children with VUR, a formal as the guideline was being developed. urethral” and “antibiotic,” “anti biotic,” meta-analysis of randomized con- Titles were reviewed by 2 authors (Drs “antibacterial,” “anti bacterial,” “anti- trolled trials (RCTs) was conducted. Downs and Carroll) to identify all arti- microbial,” “anti microbial,” “antiinfec- First, a systematic literature review fo- cles that were potentially relevant and tive,” or “anti infective” were used. The cused on RCTs, including studies in seemed to contain original data. All ti- asterisk represents the truncation or press, was performed. tles that were considered potentially wild card symbol, which indicates that relevant by either reviewer were re- Inclusion Criteria all suffixes and variants were included. tained. Abstracts of selected articles The search was limited to the publica- RCTs published in the past 15 years were reviewed, again to identify arti- tion types and subject headings for all (1993–2009) that compared antimicro- cles that were relevant to the guideline clinical trials and included all key- bial treatment versus no treatment or and that seemed to contain original word variants for “random” in Medline placebo treatment for the prevention data. Review articles that were rele- and Embase.5 In addition, the Web site of recurrent UTI and included a mini- vant also were retained for review. www.ClinicalTrials.gov was searched mum of 6 months of follow-up monitor- Again, all abstracts that were consid- on May 20, 2010. ing were included. Published articles, ered potentially relevant by either re- The search strategy and the screening articles in press, and published ab- viewer were retained. In addition, of the titles for selection of potentially stracts were included. There were no members of the subcommittee submit- relevant abstracts were completed by language restrictions. To be included, ted articles that they thought were rel- 1 reviewer (Dr Finnell). Two reviewers studies needed to enroll children who evant to be included in the review. (Drs Finnell and Downs) screened se- had undergone VCUG for determina- Selected articles were reviewed and tion of the presence and grade of VUR. lected abstracts to identify appropri- summarized by 2 reviewers (Drs Studies that examined antibiotic pro- ate articles. Published articles and ab- Finnell and Downs). The summaries phylaxis versus no treatment or pla- stracts that met the inclusion criteria were reviewed, and articles present- cebo treatment were included. were included in the meta-analysis. Addi- ing potentially new information were tional information was sought from au- retained. In addition, representative Outcome Measures thors whose articles or abstracts did not articles reinforcing evidence in the The primary outcome was the number contain the information needed for a de- 1999 technical report were retained. of episodes of pyelonephritis or febrile cision regarding inclusion. The selection The most significant area of change in UTI diagnosed on the basis of the pres- process is summarized in Fig 2. the UTI landscape was a new and grow- ence of fever and bacterial growth in ing body of evidence regarding the ef- urine cultures. A secondary outcome Assessment of Studies fectiveness of antimicrobial prophy- was an episode of any type of UTI, in- The quality of selected articles and ab- laxis to prevent recurrent infections in cluding cystitis, nonfebrile UTI, and stracts was assessed with the scoring PEDIATRICS Volume 128, Number 3, September 2011 e751 Downloaded from by guest on November 1, 2015
Meta-analyses All statistical tests were performed by using Review Manager 5.1 (Nordic Co- chrane Centre, Copenhagen, Den- mark). The following settings were used for the analyses: dichotomous outcome and Mantel-Haenzel statisti- cal method. Data were analyzed with a random-effects model. When no statis- tically significant effect and no statisti- cal heterogeneity were detected, data also were analyzed with a fixed-effects model, because that type of analysis is more likely to detect a difference. The effect measure was presented as a risk ratio (RR). The results for the pri- mary outcome (pyelonephritis or fe- brile UTI) and the secondary outcome (any type of UTI, including cystitis, non- febrile UTI, and asymptomatic bacteri- uria) were calculated as point esti- mates with corresponding 95% confidence intervals (CIs). Heterogene- ity was analyzed by using the Q statistic with a threshold of P ⬍ .05. The num- ber of studies was insufficient for as- sessment of publication bias with a funnel plot. Meta-analyses of Data According to VUR Grade and for Children 2 to 24 Months of Age The published data on which the meta- analyses were based did not contain subgroup data relevant to the practice guideline. Specifically, some studies did not report outcomes according to the severity of VUR, and some did not report outcomes specific to the age range of interest (2–24 months). FIGURE 2 Therefore, the committee chairperson Study selection for meta-analyses. contacted the authors of the reports included in the meta-analysis, to ob- tain original data. Data on recurrence system described by Downs and Black which evaluated febrile UTI or pyelone- according to VUR grade and for the in 1998.6 Each study received scores phritis as the outcome. A second meta- subgroup of children 2 to 24 months of (from 2 assessors) on a scale from 0 to analysis, which included all studies age were received from the authors, 32. Six of the articles and abstracts with the outcome “all UTI,” also was and these data were analyzed in sepa- were included in a first meta-analysis, conducted. rate meta-analyses. e752 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS RESULTS TABLE 1 LRs and Posttest Probabilities of UTI for Infant Boys According to Number of Findings Present Surveillance of Recent Literature Finding LR Posttest Probability, % The surveillance of recent literature All Boys Circumcised Boys Uncircumcised yielded 1308 titles. Of those, 297 ab- Boys stracts were selected for review. From Positive Negative After After After After After After Positive Negative Positive Negative Positive Negative among the abstracts, 159 articles Results Results Results Results Results Results were selected for full review. The re- Uncircumcised 2.8 0.33 5.9 0.7 — — — — sults of this surveillance, as well as the History of UTI 2.6 0.96 5.5 2.1 1.8 0.7 14.0 5.7 full review and meta-analyses, are or- Temperature of ⬎39°C 1.4 0.76 3.1 1.7 1.0 0.5 8.1 4.5 Fever without apparent 1.4 0.69 3.1 1.5 1.0 0.5 8.1 4.1 ganized according to the evidence dia- source gram in Fig 1. Ill appearance 1.9 0.68 4.1 1.5 1.3 0.5 10.6 4.1 Fever for ⬎24 h 2.0 0.9 4.3 2.0 1.4 0.6 11.1 5.3 Nonblack race 1.4 0.52 3.1 1.2 1.0 0.4 8.1 3.2 Box 1: Prevalence and Risk Factors for UTI The Presence of UTI Should Be gether, these estimates are consistent clude boys with a history of UTI, be- Considered for Any Child 2 Months with a pooled prevalence of 5% deter- cause the guideline addresses only to 2 Years of Age With Unexplained mined in earlier studies. first-time UTIs, and to exclude those Fever The previous technical report exam- with ill appearance, because they are ined the effects of age, gender, and cir- likely to require antimicrobial agents, The previous technical report de- cumcision status on the prevalence of in which case a urine specimen would scribed a very consistent UTI preva- UTI. The conclusion was that boys more be required. Finally, boys with and lence of 5% among children 2 to 24 than 1 year of age who had been cir- without circumcision should be con- months of age with a fever without ob- cumcised were at sufficiently low risk sidered separately. This leaves 4 risk vious source. In 1996, Hoberman et al7 of UTI (⬍1%) that evaluation of this factors for boys who present with fe- conducted a study of urine diagnostic subpopulation would not be cost- ver, namely, temperature above 39°C, tests with a cohort of 4253 infants with effective. New work confirms an ap- fever for more than 24 hours, no ap- fever and found a prevalence of 5%. proximately threefold to fourfold de- parent fever source, and nonblack Similarly, in a 1999 cohort study of 534 creased risk of UTI among circumcised race. All 4 have similar LRs. If 2 as- children 3 to 36 months of age with a boys.10 The difference seems to be sumptions are made, then the decision temperature of more than 39°C and no greater for younger children.11 Addi- rule can be simplified. The first as- apparent source of fever, UTI preva- tional clinical characteristics were sumption is that, as a first approxima- lence was determined to be 5%.8 In a shown more recently to affect the risk tion, each risk factor has a positive LR 1998 cohort study of 2411 children of UTI among febrile infants and chil- of 1.4 and a negative LR of 0.7. The sec- (boys and girls ⬍12 months of age and dren. From a study by Shaikh et al,12 a ond assumption is that the presence of girls 12–24 months of age) seen in the set of likelihood ratios (LRs) for vari- each risk factor is conditionally inde- emergency department with a temper- ous risk factors for UTI was derived pendent of the others, given the pres- ature of more than 38.5°C, Shaw et al9 (Table 1). ence or absence of UTI. With these rea- determined the prevalence of UTI to be 3.3%. Because 84% of those children A simplified way to examine the data on sonable assumptions, Table 2 applies were black, this estimate may be low boys from Shaikh et al12 is first to ex- to boys with no previous history of UTI for the general population (see below). In a meta-analysis of 14 studies, the TABLE 2 LRs and Posttest Probabilities of UTI for Febrile Infant Boys According to Number of pooled prevalence of UTI was 7% (95% Findings Present CI: 5.5%– 8.4%) among febrile children No. of Risk Factors LR Posttest Probability, % 0 to 24 months of age, of both genders, All Boys Uncircumcised Circumcised with or without additional symptoms 0 0.34 0.8 2.1 0.2 of UTI.10 In the 6- to 12-month age 1 0.69 1.5 4.1 0.5 2 1.37 3.0 7.9 1.0 group, however, the prevalence was 3 2.74 5.8 14.7 1.9 5.4%; in the 12- to 24-month age group, 4 5.49 11.0 25.6 3.7 the prevalence was 4.5%. Taken to- Risk factors: temperature above 39°C, fever for more than 24 hours, no apparent fever source, and nonblack race. PEDIATRICS Volume 128, Number 3, September 2011 e753 Downloaded from by guest on November 1, 2015
TABLE 3 LRs and Posttest Probabilities of UTI for Febrile Infant Girls According to Number of TABLE 4 LRs and Posttest Probabilities of UTI Findings Present (Prospective Original Study) for Febrile Infant Girls According to Cutoff Value, No. LR Posttest Probability, % Number of Findings Present (Retrospective Validation Study) of Factors Positive Negative Below At or Above No. of LR Posttest (Approximate) Cutoff Value Cutoff Value Findings Probability, % 1 1.04 0.20 0.8 5.1 0 or 1 1.02 0.8 2 1.35 0.17 0.8 6.5 2 1.10 0.9 3 2.5 0.42 2.1 11.4 3 1.26 1.0 4 9.4 0.79 3.9 33.0 4 3.04 2.4 5 15.8 0.95 4.7 45.0 5 2.13 1.7 Risk factors: less than 12 months of age, white race, temperature ⬎ 39°C, fever for at least 2 days, and absence of another Risk factors: less than 12 months of age, white race, tem- source of infection. perature ⬎ 39°C, fever for at least 2 days, and absence of another source of infection. and do not appear ill. The LR is calcu- age, white race, temperature of lated as LR ⫽ (1.4)p ⫻ (0.7)n, where p more than 39°C, fever for at least 2 is the number of positive findings and days, or absence of another source number of risk factors. Similar results n is the number of negative findings. of infection. could be derived from the validation This assumes that the clinician has as- However, those authors evaluated study and are shown in Table 4. How- sessed all 4 risk factors. It should be their decision rule with several differ- ever, because the second study had a noted that, for uncircumcised boys, ent cutoff points, to determine the weaker design, the values in Table 3 the risk of UTI never decreases below score below which the risk of UTI de- are more reliable. 2%. For circumcised boys, the proba- creased below a test threshold of 1%. These studies provide criteria for bility exceeds 1% if there are 2 or more Unfortunately, the published article practical decision rules that clini- risk factors. did not include the set of negative LRs cians can use to select patients who Other studies have shown that the needed to reproduce the posterior need urine samples for analysis presence of another, clinically obvious probabilities.17 However, it was possi- and/or culture. They do not establish source of infection,13 particularly doc- ble to approximate them through ex- a threshold or maximal risk of UTI umented viral infections,14 such as re- trapolation from the receiver operat- above which a urine sample is spiratory syncytial virus infections,15 ing characteristic curve presented. On needed. However, in surveys of pedi- reduces the risk of UTI by one-half. In a the basis of these estimated negative atricians, Roberts et al18 found that series of studies conducted by Gore- LRs and the positive LRs provided in only 10% of clinicians thought that a lick, Shaw, and others,9,16,17 male gen- the article,17 Table 3 was derived. For urine culture is indicated if the prob- der, black race, and no history of UTI each cutoff value in the number of risk ability of UTI is less than 1%. In addi- were all found to reduce the risk. The factors, Table 3 shows the posterior tion, the cost-effectiveness analysis authors derived a prediction rule spe- probability for children with fewer than published in the 1999 technical re- cifically for girls, with 95% sensitivity that number of risk factors (below the port set a threshold of 1%. However, and 31% specificity. In a subsequent cutoff value) and for those with that circumstances such as risk of loss to validation study, they confirmed that number of risk factors or more. There- follow-up monitoring or other clini- these findings had predictive power, fore, the posttest probability is not the cian concerns may shift this thresh- but the validation study used a weaker, risk of UTI for children with exactly that old up or down. retrospective, case-control design, compared with the more-robust, pro- spective, cohort design of the original TABLE 5 List of Test Characteristics of Diagnostic Tests for UTI Reported in 1999 Technical Report2 derivation study. On the basis of the Test Sensitivity, % Specificity, % earlier cohort study and starting with Range Median Mean Range Median Mean a baseline risk of 5%, a child scoring Leukocyte esterase test 67–94 84 83 64–92 77 78 low on the prediction rule would Nitrite test 15–82 58 53 90–100 99 98 have a slightly less than 1% risk of Blood assessment 25–64 53 47 60–89 85 78 Protein assessment 40–55 53 50 67–84 77 76 UTI. To score this low on the predic- Microscopy, leukocytes 32–100 78 73 45–98 87 81 tion rule, a young girl would have to Microscopy, bacteria 16–99 88 81 11–100 93 83 exhibit no more than 1 of the follow- Leukocyte esterase or nitrite test 90–100 92 93 58–91 70 72 ing features: less than 12 months of Any positive test results in urinalysis 99–100 100 99.8 60–92 63 70 e754 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS TABLE 6 Test Characteristics of Laboratory Tests for UTI in Children Study Test Population n Sensitivity, % Specificity, % Lockhart et al19 (1995) Leukocyte esterase or nitrite test results Prospective sample, ⬍6 mo of 207 67 79 positive age, ED Any bacteria with Gram-staining Hoberman et al7 (1996) ⬎10 white blood cells per counting chamber ⬍2 y of age, 95% febrile, ED 4253 96 93 or any bacteria per 10 oil emersion fields Shaw et al9 (1998) Enhanced urinalysis Infants ⬍12 mo of age and girls 3873 94 84 Dipslide or standard urinalysis ⬍2 y of age, ⱖ38.5°C, ED 83 87 Lin et al20 (2000) Hemocytometer, ⱖ10 cells per L Systematic review, febrile infants NA 83 89 hospitalized, febrile UTI ED indicates emergency department; NA, not applicable. Box 2: Diagnostic Tests for UTI Obtaining a Urine Sample the positive predictive value of a positive The 1999 technical report reviewed a In the UTI practice parameters from culture result for urine obtained in a bag large number of studies that de- 1999, the subcommittee defined the would be 15%. This means that, of all pos- scribed diagnostic tests for UTI. The re- gold standard of a UTI to be growth of itive culture results for urine obtained in bacteria on a culture of urine obtained a bag, 85% would be false-positive sults are summarized in Table 5. This through suprapubic aspiration (SPA). results. updated review of the literature largely reinforced the findings of the In the previous technical report, SPA was reported to have success rates Box 3: Short-term Treatment of UTIs original technical report. ranging from 23% to 90%,22–24 although General Principles of Treatment More-recent work compared micros- higher success rates have been Published evidence regarding the short- copy, including the use of hemocytom- achieved when SPA is conducted under term treatment of UTIs supports 4 main eters and counting chambers (en- ultrasonographic guidance.25,26 SPA is hanced urinalysis), with routine points. First, complications, such as bac- considered more invasive than cathe- teremia or renal scarring, are suffi- urinalysis or dipslide reagents (Table terization and, in RCTs from 200627 and ciently common to necessitate early, 6). Lockhart et al19 found that the ob- 2010,28 pain scores associated with thorough treatment of febrile UTIs in in- servation of any visible bacteria in an SPA were significantly higher than fants.35 Second, treatment with orally ad- uncentrifuged, Gram-stained, urine those associated with catheterization. ministered antimicrobial agents is as ef- sample had better sensitivity and This result was found for both boys fective as parenteral therapy.36,37 Third, specificity than did combined dipslide and girls. Similar to previous studies, bacterial sensitivity to antimicrobial leukocyte esterase and nitrite test re- these RCTs also revealed lower suc- agents is highly variable across time and sults. Hoberman et al7 in 1996 and cess rates for SPA (66% and 60%), geographic areas, which suggests that Shaw et al20 in 1998 both evaluated en- compared with catheterization (83% therapy should be guided initially by lo- hanced urinalysis, consisting of more and 78%).27,28 In comparison with SPA cal sensitivity patterns and should be ad- than 10 white blood cells in a counting results, cultures of urine specimens justed on the basis of sensitivities of chamber or any bacteria seen in 10 oil obtained through catheterization are isolated pathogens.38,39 Fourth, meta- emersion fields; they found sensitivity 95% sensitive and 99% specific.7,11,12 analyses have suggested that shorter of 94% to 96% and specificity of 84% Cultures of bag specimens are difficult durations of oral therapy may not have a to 93%. In 2000, Lin et al21 found that to interpret. In the original technical disadvantage over longer courses for a count of at least 10 white blood report, sensitivity was assumed to be UTIs. However, those studies largely ex- cells per L in a hemocytometer was 100% but the specificity of bag cultures cluded febrile UTI and pyelonephritis.40 less sensitive (83%) but quite spe- was shown to range between 14% and cific (89%). Given the sensitivity of 84%.2 Our updated surveillance of the Experimental and Clinical Data enhanced urinalysis, the probability literature did not show that these num- Support the Concept That Delays in of UTI for a typical febrile infant with bers have improved.29–33 One article the Institution of Appropriate a previous likelihood of UTI of 5% suggested that a new type of collection Treatment for Pyelonephritis Increase would be reduced to 0.2% to 0.4% bag may result in improved specificity,34 the Risk of Renal Damage with negative enhanced urinalysis but that study was not controlled. With a The 1999 technical report cited evi- results. prevalence of 5% and specificity of 70%, dence that febrile UTIs in children less PEDIATRICS Volume 128, Number 3, September 2011 e755 Downloaded from by guest on November 1, 2015
TABLE 7 Recent Studies Documenting the Prevalence of VUR Among Children With UTI Study Description n Prevalence, % Sargent and Stringer50 (1995) Retrospective study of first VCUG for UTI in children 1 wk to 15 y of age 309 30 Craig et al51 (1997) Cross-sectional study of children ⬍5 y of age with first UTI 272 28 McDonald et al52 (2000) Retrospective chart review of children with VCUG after UTI 176 19 Oostenbrink et al53 (2000) Cross-sectional study of children ⬍5 y of age with first UTI 140 26 Mahant et al54 (2001) Retrospective chart review of children with VCUG after UTI 162 22 Mahant et al55 (2002) Retrospective review of VCUG in children ⬍5 y of age admitted with first UTI 162 22 Chand et al56 (2003) Retrospective review of VCUG or radionuclide cystogram in children ⬍7 y of age 15 504 35 Fernandez-Menendez et al44 (2003) Prospective cohort study of 158 children ⬍5 y of age (85% ⬍ 2 y) with first UTI 158 22 Camacho et al41 (2004) Prospective cohort study of children 1 mo to 12 y of age (mean age: 20 mo) with 152 21 first febrile UTI Hansson et al57 (2004) Retrospective cross-sectional study of children ⬍2 y of age with first UTI 303 26 Pinto58 (2004) Retrospective chart review of first VCUG for UTI in children 1 mo to 14 y of age 341 30 Zamir et al59 (2004) Cohort study of children 0–5 y of age hospitalized with first UTI 255 18 than 2 years of age are associated with renal parenchymal damage at 6 to 12 Proof of Cure bacterial sepsis in 10% of cases.35 Fur- months (3 studies; RR: 0.80 [95% CI: Data supporting routine repeat cultures thermore, renal scarring is common 0.50 –1.26]) between oral antimicro- of urine during or after completion of an- among children who have febrile UTIs. bial therapy (10 –14 days) and intrave- timicrobial therapy were not available The risk is higher among those with nous antimicrobial treatment (3 days) for the 1999 technical report. Retrospec- higher grades of VUR41 but occurs with followed by oral antimicrobial treat- tive studies did not show “proof of bacte- all grades, even when there is no VUR. ment (11 days). riologic cure” cultures to be benefi- Although it was not confirmed in all cial.47,48 Studies demonstrating that studies,42,43 older work2 and newer Duration of Therapy clinical response alone ensures bacteri- studies44 demonstrated an increased In the 1999 technical report, data ologic cure are not available. risk of scarring with delayed treat- slightly favoring longer-duration (7–10 ment. Children whose treatment is de- Box 4: Evaluation and Management days) over shorter-duration (1 dose to layed more than 48 hours after onset of Urinary Tract Abnormalities 3 days) antimicrobial therapy for pedi- of fever may have a more than 50% Prevalence of VUR atric patients with UTIs were pre- higher risk of acquiring a renal scar. sented.2 Since then, several meta- Several cohort studies published since Oral Versus Intravenous Therapy analyses with different conclusions the 1999 technical report provide esti- In a RCT from 1999, Hoberman et al36 have been published on this topic.40,45,46 mates of the prevalence of VUR of var- studied children 1 to 24 months of age A 2003 Cochrane review addressing ious grades among infants and chil- with febrile UTIs. They compared 14 the question analyzed studies that ex- dren with UTIs (Table 7). Overall, these days of oral cefixime treatment with 3 amined the difference in rates of re- estimates are reasonably consistent days of intravenous cefotaxime treat- currence for positive urine cultures af- with those reported in earlier studies, ment followed by oral cefixime treat- ter treatment.40 It compared short although the grades of reflux are now ment to complete a 14-day course. The (2– 4 days) and standard (7–14 days) reported more consistently, by using investigators found no difference in duration of treatment for UTIs and the international system of radio- outcomes between children who were found no significant difference in the graphic grading of VUR.49 treated with an orally administered, frequency of bacteriuria after comple- The prevalence of VUR among children third-generation cephalosporin alone tion of treatment (8 studies; RR: 1.06 in these studies varies between 18% and those who received intravenous [95% CI: 0.64 –1.76]). Although the au- and 35%. The weighted average preva- treatment. thors of the review did not exclude lence is 34%, but this is largely driven In a Cochrane review, Hodson et al37 studies of children with febrile UTIs or by the enormous retrospective study evaluated studies with children 0 to 18 pyelonephritis, each individual study by Chand et al.56 Most studies report a years of age, examining oral versus in- included in the meta-analysis had al- rate of 24% or less, which is less than travenous therapy. No significant dif- ready excluded such children. To date, the estimate of VUR prevalence in the ferences were found in duration of fe- there are no conclusive data on the du- 1999 technical report. ver (2 studies; mean difference: 2.05 ration of therapy for children with fe- Data on the prevalence of VUR among hours [95% CI: ⫺0.84 to 4.94 hours]) or brile UTIs or pyelonephritis. children without a history of UTI do not e756 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS would expect grade V reflux to be pres- ent in ⬍1% of children with a first UTI. It has been suggested that the risk of VUR and, more specifically, high- grade VUR may be higher for chil- dren with recurrent UTI than for chil- dren with a first UTI. Although it was not tested directly in the studies re- FIGURE 3 viewed, this idea can be tested and Prevalence of VUR as a function of the midpoint of each age stratum, as reported by Chand et al.56 the magnitude of the effect can be estimated from the data found in the literature search for this meta-anal- ysis.64–70 These data clearly demon- strate that the risk of UTI recurrence is associated with VUR (Fig 5). Further- more, this relationship allows the like- lihood of each grade of reflux (given that a UTI recurrence has occurred) to be estimated by using Bayes’ theorem, as follows: p(VURi|UTI) FIGURE 4 Distribution of reflux grades among children with VUR.41,44,51,56,57,62,63 p(UTI|VURi) ⫻ p(VURi) ⫽ 冘 , p(UTI|VURi) ⫻ p(VURi) V i⫽0 exist. Using a retrospective approach predominance of each reflux grade, and existing urine culture data, Han- but grades II and III consistently are where p(UTI|VURi) refers to the proba- nula and Ventola and colleagues,60,61 in the most common. With the exception bility of VUR of grade i given the recur- 2 separate publications, found similar of the study by Camacho et al,41 all rence of UTI. If it is assumed that the rates of prevalence of any grade of VUR studies showed grades IV and V to be conditional probabilities remain the among children with proven (37.4%) or the least frequent, and grade V ac- same with second or third UTIs, then certain (36%) UTI versus false (34.8%) or counted for 0% to 5% (weighted aver- Bayes’ theorem can be reapplied for a improbable (36%) UTI. These results sug- age: 3%) of reflux. With that value mul- third UTI as well. gest that VUR is prevalent even among tiplied by the prevalence of VUR among By using estimates of p(UTI VUR) (Fig 5) children without a history of UTI. young children with a first UTI, we and the previously determined distri- The prevalence of VUR decreases with age. This was approximated by analy- sis across studies in the 1999 technical report. Since then, Chand et al56 re- ported the prevalence VUR within age substrata of their cohort. Figure 3 shows the prevalence of VUR plotted as a function of the midpoint of each age stratum. Seven studies reported the preva- lence of different grades of reflux, by using the international grading sys- tem.41,44,51,56,57,62,63 The distributions of different reflux grades among children FIGURE 5 who had VUR are shown in Fig 4. There Probability of a recurrent febrile UTI as a function of VUR grade among infants 2 to 24 months of age is significant variability in the relative in the control groups of the studies included in meta-analyses.64,66–70 PEDIATRICS Volume 128, Number 3, September 2011 e757 Downloaded from by guest on November 1, 2015
other fever source and, (2) even within similar populations, reported rates vary widely. Ultrasonography yields ⬃15% positive results. However, it has a ⬃70% false- negative rate for reflux, scarring, and other abnormalities. Limited data exist regarding the false-negative rate for high-grade VUR (grade IV and V), but the studies reviewed presented 0% to FIGURE 6 40% false-negative rates for detection Distribution of VUR grades after different numbers of UTIs. of grade IV reflux through ultrasonog- raphy.59,74 Among the 15% of results butions of VUR grades (Fig 4), a very very high, approaching 100%.76 There- that are positive, between 1% and 24% approximate estimate of the distribu- fore, ultrasonography in the case of a are false-positive results. Of the true- tion of VUR grades after the first, sec- child with a UTI who is not responding positive results, ⬃40% represent ond, and third UTI can be made (Fig 6). to therapy as expected can be very some dilation of the collecting system, The likelihood that there is no VUR de- helpful in ruling out these infectious such as would be found on a VCUG; 10% creases rapidly. Conversely, the likeli- complications. represent abnormalities that are po- hood of VUR grades III to V increases Ultrasonography also is advocated for tentially surgically correctable (eg, rapidly. The risk of grades I and II screening for renal abnormalities ureteroceles or ureteropelvic junction changes little. such as hydronephrosis, suggesting obstruction). Approximately one-half posterior urethral valves, ureteropel- represent findings such as horseshoe Ultrasonography kidneys or renal scarring, for which vic junction obstruction, or ureteroce- Ultrasonography is used as a noninva- les. The evidence model illustrates the there is no intervention but which sive technique to identify renal abnor- expected outcomes from routine ultra- might lead to further evaluations, such malities in children after UTI. The sensi- sonography of the kidneys, ureters, as technetium-99m–labeled dimercap- tivity of the test varies greatly and has and bladder after the first febrile UTI in tosuccinic acid renal scintigraphy. The been reported to be as low as 5% for infants and young children (Fig 7). The 40% with dilation of the collecting detection of renal scarring71–73 and 10% model is based on the study results system are problematic. This repre- for detection of VUR.74 However, most documented in Tables 8 and 9 and a sents only a small fraction of children studies report moderate specificity. strategy of performing kidney and (15% ⫻ 88% ⫻ 40% ⫽ 5%) with first One possible reason for a decrease in bladder ultrasonography for all in- UTIs who would be expected to have specificity is that, in animal models, fants with UTIs. The numbers are not VUR before ultrasonography. Ultra- Escherichia coli endotoxin has been exact for 2 reasons, namely, (1) study sonography does not seem to be en- shown to produce temporary dilation populations vary and do not always riching for this population (although of the urinary tract during acute infec- precisely meet the definitions of 2 to 24 ultrasonography might identify a pop- tion.75 Therefore, use of routine ultra- months of age and febrile without an- ulation with higher-grade VUR). sonography for children with UTIs dur- ing acute infection may increase the false-positive rate. However, no human data are available to confirm this hypothesis. Ultrasonography is used during acute infection to identify renal or perirenal abscesses or pyonephrosis in children who fail to experience clinical improve- ment despite antimicrobial therapy. The sensitivity of ultrasonography for FIGURE 7 such complications is thought to be Evidence model for ultrasonography after a first UTI. e758 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS TABLE 8 Summary of Ultrasonography Literature studies were RCTs comparing prophy- Study n/N (%) Comments lactic antimicrobial agent use with False-negative rate some type of surgical intervention. Scarring None of those studies included a pla- Smellie et al73 (1995) 7/20 (35) Barry et al77 (1998) 23/170 (14) cebo arm.90–97 One study compared dif- Moorthy et al71 (2004) 219/231 (95) ferent lengths of antimicrobial prophy- Sinha et al78 (2007) 61/79 (77) Reported as renal units laxis.98 Another study compared Montini et al79 (2009) 33/45 (73) VUR different antimicrobial regimens but Smellie et al73 (1995) 21/36 (58) did not include a placebo arm.99 Six- Mahant et al55 (2002) 14/35 (40) teen studies were determined, on Hoberman et al74 (2003) 104/117 (90) Zamir et al59 (2004) 38/47 (81) closer inspection, to be not clinical Montini et al79 (2009) 48/66 (73) trials but prospective cohort studies, Other reviews, systematic reviews, or Smellie et al74 (1995) 5/5 (100) Duplex kidney meta-analyses. Twelve studies were False-positive rate Scarring found twice, either in Medline or Em- Barry et al77 (1998) 11/478 (2) base and the Cochrane Clinical Trials Moorthy et al71 (2004) 12/699 (1.7) Registry. Sinha et al78 (2007) 9/870 (1) Monitini et al79 (2009) 26/255 (10) One article was excluded after full re- VUR view (Fig 2). That study compared pro- Smellie et al73 (1995) 2/12 (17) Normal VCUG, DMSA, and IVU results Mahant et al55 (2002) 30/127 (24) phylactic antimicrobial agent use with Hoberman et al74 (2003) 17/185 (10) probiotic use.65 The study was not in- Zamir et al59 (2004) 27/208 (13) cluded in the meta-analysis, but the re- Other Giorgi et al80 (2005) 21/203 (10) sults are described separately. IVU indicates intravenous urography; DMSA, dimercaptosuccinic acid. There are RCTs of antimicrobial pro- phylaxis that are older than 15 years. In 4 studies from the 1970s, a total of Prenatal Ultrasonography were not described. These studies sug- 179 children were enrolled.100–103 Urinary tract abnormalities also may gest that normal prenatal ultrasono- Less than 20% of those children had be identified during prenatal ultra- graphic findings may not be sufficient to VUR. Because of limited reporting of sonography,85–87 which theoretically obviate the need for additional studies if results in that subgroup, those older would decrease the number of new ab- a UTI occurs in infancy. studies were not included in the normalities found through later ultra- analyses. sonography.81 However, the extent to Results of Targeted Literature Two additional RCTs comparing antimi- which normal prenatal ultrasono- Review and Meta-analysis on crobial prophylaxis and placebo treat- graphic findings decrease the need for Prophylaxis to Prevent Recurrent ment for children were published in later studies remains in doubt. UTI October 2009.69,70 The first trial en- Miron et al88 studied 209 children who Study Identification rolled children 0 to 18 years of age af- underwent ultrasonography prena- ter a first UTI, with 2% of enrolled chil- For the meta-analysis of studies on the tally and again after a UTI. They found dren (12 of 576 children) being more effectiveness of antimicrobial agents to that, among 9 children with abnormal than 10 years of age. The second trial prevent recurrent UTI in children with ultrasonographic results after UTI, 7 had enrolled children diagnosed as having VUR, we reviewed a total of 213 titles normal prenatal ultrasonographic re- VUR after a first UTI (194 [96%] of 203 from our primary literature search. Of children) or after prenatal ultrasonog- sults. These cases included 3 cases of hydronephrosis, 3 cases of moderate di- those, 45 were retained for abstract re- raphy (9 [4%] of 203 children), who lation, and 1 case of double collecting view on the basis of the title, of which 7 were then assigned randomly to re- system. Similarly, in a study by Lakhoo et were selected for full review. Six of the ceive antimicrobial prophylaxis, sur- al89 in 1996, 22 of 39 children with UTIs studies met the inclusion criteria. Figure veillance, or endoscopic therapy, at 1 had normal prenatal ultrasonographic 2 summarizes the selection process. to 2 years of age. The majority of these results but “abnormal” post-UTI ultra- Thirty-eight abstracts were excluded children (132 children [65%]) had sonographic results; the abnormalities before full review (Fig 2). Eight of those been diagnosed as having VUR before 1 PEDIATRICS Volume 128, Number 3, September 2011 e759 Downloaded from by guest on November 1, 2015
TABLE 9 Distribution of Positive Ultrasonographic Findings year of age and thus had been receiv- Study n/N (%) ing prophylaxis before random assign- Alon and Ganapathy62 (1999) 19/124 (15) ment. These studies were included in Minimal unilateral changes VUR 2 (1.6) the meta-analysis. Normal VCUG findings 2 (1.6) Resolved on repeat study 2 (1.6) Not monitored further 3 (2.4) Description of Included Studies Major changes 8 (6.5) Table 10 presents characteristics of VUR 1 (1.6) Normal findings 1 (1.6) the 8 included studies.64,66–70,104,105 Four Posterior urethral valve 1 (1.6) studies enrolled children after diagno- Hydroureternephrosis 1 (1.6) Gelfand et al81 (2000) 141/844 (16.7) sis of a first episode of pyelonephri- Bladder wall thickening 31 (3.7) tis.64,66–68 In those 4 studies, pyelone- Hydroureter 6 (0.7) Parenchymal abnormalities 42 (5.0) phritis was described as fever of more Pelvocalyceal dilation 27 (3.2) than 38°C or 38.5°C and positive urine Renal calculus 1 (0.1) Simple renal cyst 1 (0.1) culture results. In 1 of those studies,67 Urethelial thickening 31 (3.7) dimercaptosuccinic acid scanning re- Jothilakshmi et al82 (2001) 42/262 (16) Duplex kidney 3 (1) sults consistent with acute pyelone- Crossed renal ectopia 1 (0.38) phritis represented an additional Horseshoe kidney 1 (0.38) Hydronephrosis 5 (1.9) requirement for inclusion. The remain- Megaureter 6 (2.3) ing studies had slightly different inclu- Polycystic kidney 1 (0.38) Pelviureteric junction obstruction 1 (0.38) sion criteria. In the study by Craig et Posterior urethral valve 2 (0.76) al71 from 2009, symptoms consistent Renal calculus 3 (0.01) Rotated kidney 2 (0.76) with UTI and positive urine culture re- Ureterocele 2 (0.76) sults were required for inclusion. Fe- VUR 7 (2.7) Hoberman et al74 (2003) 37/309 (12) ver was documented for 79% of en- Dilated pelvis 13 (4.2) rolled children (454 of 576 children). In Pelvocaliectasis 12 (3.9) Hydronephrosis 2 (0.6) the study by Brandström et al,70 96% of Dilated ureter 9 (2.9) enrolled children (194 of 203 children) Double collecting system 3 (1.0) Extrarenal pelvis 1 (0.3) had pyelonephritis, defined in a similar Calculus 1 (0.3) manner as in the 6 initial studies. The Zamir et al59 (2004) 36/255 (14.1) Mild unilateral pelvis dilation 32 (12.5) remaining patients were enrolled af- Moderate unilateral pelvis dilation 1 (0.04) ter prenatal diagnosis of VUR. The 2 Enlargement kidney 1 (0.04) Small renal cyst 1 (0.04) included abstracts described studies Double collecting system and severe hydronephrosis 1 (0.04) that enrolled any child with VUR and Jahnukainen et al83 (2006)a 23/155 (14.8) Hydronephrosis 8 (5) not only children who had had pyelone- Double collecting system 11 (7) phritis.104,105 Seven of the 8 studies (all Multicystic dysplasia 1 (0.6) Renal hypoplasia 1 (0.6) except the study by Reddy et al108) re- Solitary kidney 1 (0.6) ported a gender ratio. Among those Horseshoe kidney 1 (0.6) Huang et al84 (2008) 112/390 (28.7) studies, there were 67% girls and 33% Nephromegaly 46 (11.8) boys. Six studies compared antimicro- Isolated hydronephrosis 20 (5.1) Intermittent hydronephrosis 3 (0.8) bial treatment with no treatment. Only Hydroureter 8 (2.1) 2 studies were placebo controlled, and Hydroureter and hydronephrosis 3 (0.8) those 2 were the only blinded stud- Thickened bladder wall 11 (2.8) Small kidneys 8 (2.1) ies.69,105 The grade of VUR among the Simple ureterocele 5 (1.3) enrolled children varied from 0 to V, Double collecting systems 4 (1.0) Increased echogenicity 3 (0.8) but few of the children had grade V Horseshoe kidney 1 (0.3) VUR. Montini et al79 (2009) 38/300 (13) Dilated pelvis, ureter, or pelvis and calyces 12 (4) The ages of children included in the Renal swelling or local parenchymal changes 10 (3.3) Increased bladder wall or pelvic mucosa, thickness 6 (2) initial meta-analyses were 0 to 18 Other 10 (3.3) years; therefore, some children were a Hospitalized children with UTI. included who were outside the target e760 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
FROM THE AMERICAN ACADEMY OF PEDIATRICS TABLE 10 Studies Included in Meta-analysis Study Study Sites n Age VUR Grade Antimicrobial Agents Control Follow-up Outcome Period, VUR No mo VUR Craig et al105 (2002) Australia 46 0 0–3 mo I–V TMP-SMX Placebo 36 UTI and renal damage Craig et al69 (2009) Australia 243 234 0–18 y I–V TMP-SMX Placebo 12 Symptomatic UTI, febrile UTI, hospitalization, and renal scarring Garin et al67 (2006) Chile, Spain, 113 105 3 mo to 18 y 0–III TMP-SMX/ No treatment 12 Asymptomatic UTI, cystitis, United States nitrofurantoin pyelonephritis, and renal scarring Brandström et al70 Sweden 203 0 1–2 y III–IV TMP-SMX/cefadroxil, No treatment 48 Febrile UTI, reflux status, (2010) nitrofurantoin and renal scarring Montini et al66 (2008) Italy 128 210 2 mo to 7 y 0–III TMP-SMX/amoxicillin- No treatment 12 Febrile UTI and renal clavulanate scarring Pennesi et al68 (2008) Italy 100 0 0–30 mo II–IV TMP-SMX No treatment 48 UTI and renal scarring Reddy et al104 (1997) United States 29 0 1–10 y I–V TMP-SMX/ No treatment 24 UTI, progression of disease, nitrofurantoin need for surgery, parental compliance Roussey-Kesler et al64 France 225 0 1–36 m I–III TMP-SMX No treatment 18 Febrile and afebrile UTI (2008) TMP-SMX indicates trimethoprim-sulfamethoxazole. age range for this report and for whom mercaptosuccinic acid scans) in the dif- rates of recurrence of pyelonephritis, re- other factors (eg, voiding and bowel ferent articles. gardless of age or degree of reflux. Al- habits) might have played a role. The though prophylaxis seems to reduce sig- median age of the included children, Quality Assessment nificantly but only slightly the risk of UTI however, was not above 3 years in any The included studies received scores when all forms are included, most of this of the included studies in which it was (from 2 assessors) from 7 to 26 (scale effect is attributable to reductions in reported. Separate meta-analyses range: 0 –32) with the scoring system de- rates of cystitis or asymptomatic bacte- were subsequently performed for the scribed by Downs and Black,6 with a me- riuria, which would not be expected to subgroup of children who were 2 to 24 dian score of 16. Score deductions re- lead to ongoing renal damage. months of age. The duration of antimi- sulted from lack of blinding of patients crobial treatment and follow-up moni- (all except 2 studies69,105), lack of blinding Recurrence of Pyelonephritis/Febrile toring ranged from 12 to 48 months. of assessors (all except 2 studies69,105), UTI Among All Studied Children With The antimicrobial agents used were limited or no information about patients VUR of Any Grade trimethoprim-sulfamethoxazole (1–2 lost to follow-up monitoring (3 stud- Recurrence of pyelonephritis was or 5–10 mg/kg),64,68,69,105 trimethoprim- ies64,67,104), lack of reporting of adverse reported in 6 of the 8 studies. The study sulfamethoxazole or amoxicillin-clavulanic effects (all except 2 studies66,69), and by Pennesi et al68 presented the results acid (15 mg/kg),66 trimethoprim- small sample sizes. The lowest scores, 7 as recurrence of pyelonephritis, but sulfamethoxazole or nitrofurantoin,67,104 or and 12, were received by the 2 abstracts recurrence was defined as episodes of trimethoprim-sulfamethoxazole, ce- because of lack of details in the descrip- fever or “symptoms of UTI.” When con- fadroxil, or nitrofurantoin.70 Urine col- tions of the methods.104,105 tacted, this author confirmed that all lection methods differed among stud- reported recurrences were charac- ies. Bag specimens were reported for Antimicrobial Therapy Versus No terized by fever above 38.5°C. There- 3 studies.64,66,70 In an additional 4 stud- Treatment fore, the article was included in the ies, the description of the urine collec- Overview of Findings meta-analysis. With a random-effects tion methods did not exclude the use of Described here are the results of model, there was no significant dif- bag specimens.67,68,104,105 Recurrent UTI several meta-analyses, subdivided ac- ference in rates of recurrence of py- was described as (1) asymptomatic bac- cording to type of recurrence (pyelo- elonephritis for children who re- teriuria (diagnosed through screening nephritis versus UTI), degree of VUR ceived antimicrobial therapy and cultures), (2) cystitis, (3) febrile UTI, and (none to grade V), and patient age. In those who did not. This meta- (4) pyelonephritis (diagnosed on the ba- summary, antimicrobial prophylaxis analysis yielded a RR of 0.77 (95% CI: sis of focal or diffuse uptake on di- does not seem to reduce significantly the 0.47–1.24) (Fig 8). Heterogeneity test- PEDIATRICS Volume 128, Number 3, September 2011 e761 Downloaded from by guest on November 1, 2015
FIGURE 8 Combined estimates of the effect of antimicrobial prophylaxis on prevention of pyelonephritis in children with VUR, from random-effects modeling. RRs and 95% CIs are shown. M-H indicates Mantel-Haenszel. FIGURE 9 Combined estimates of the effect of antimicrobial prophylaxis on prevention of pyelonephritis in children without VUR, from random-effects modeling. RRs and 95% CIs are shown. M-H indicates Mantel-Haenszel. ing results were significant (P ⫽ .04), TABLE 11 Combined Estimates of Effect of Antimicrobial Prophylaxis on Prevention of which indicated statistical heteroge- Pyelonephritis for All Children According to Grade of VUR neity between studies. VUR Grade No. of Children No. of Studies RR (95% CI)a 0 549 3 0.62 (0.30–1.27) Recurrence of Pyelonephritis/ I–II 455 5 0.94 (0.49–1.80) Febrile UTI Among Children of All III 347 6 0.74 (0.42–1.29) Ages Without VUR IV 122 3 0.69 (0.39–1.20) V 5 1 0.40 (0.08–1.90) There was no significant difference a From random-effects model. in rates of recurrence of pyelonephri- tis for children without VUR who re- ceived antimicrobial therapy and those who did not. With random-effects tions from each study with different (95% CI: 0.48 –1.26) (Fig 10). Hetero- modeling, the meta-analysis yielded a grades of VUR. None of those analyses geneity testing results were not signif- RR of 0.62 (95% CI: 0.30 –1.27) (Fig 9). showed a statistically significant dif- icant (P ⫽ .07). With fixed-effects mod- Heterogeneity testing results were not ference in rates of recurrence with eling, the meta-analysis yielded a RR of significant (P ⫽ .39). Because no dif- random- or fixed-effects modeling. 0.79 (95% CI: 0.58 –1.07). Heterogeneity ference was detected with a random- Random-effects modeling results are testing results were not significant effects model and there was no statis- presented. (P ⫽ .07). tical heterogeneity in this analysis, Recurrence of Pyelonephritis/Febrile Recurrence of Pyelonephritis/Febrile analysis also was conducted with a UTI Among Children 2 to 24 Months of UTI Among Children 2 to 24 Months of fixed-effects model. With fixed-effects Age With VUR of Any Grade Age With No VUR modeling, the meta-analysis yielded a There was no significant differ- There was no significant difference RR of 0.61 (95% CI: 0.31–1.23). ence in rates of recurrence of pyelo- in rates of recurrence of pyelonephri- Recurrence of Pyelonephritis/Febrile nephritis for children 2 to 24 months tis for children 2 to 24 months of age UTI Among Children of All Ages With of age with VUR who received antimi- without VUR who received antimicro- VUR, According to Grade crobial agents and those who did bial agents and those who did not. With Table 11 summarizes the results of not. With random-effects modeling, random-effects modeling, the meta- separate meta-analyses of subpopula- the meta-analysis yielded a RR of 0.78 analysis yielded a RR of 0.55 (95% CI: e762 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from by guest on November 1, 2015
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