A Trade-off Analysis of Routine Newborn Circumcision

Background. The risks associated with newborn circumcision have not been as extensively evaluated as the benefits. Objectives. The goals of this study were threefold: 1) to derive a population-based complication rate for newborn circumcision; 2) to calculate the number needed to harm for newborn circumcision based on this rate; and 3) to establish trade-offs based on our complication rates and published estimates of the benefits of circumcision including the prevention of urinary tract infections and penile cancer. Methods. Using the Comprehensive Hospital Abstract Reporting System for Washington State, we retrospectively examined routine newborn circumcisions performed over 9 years (1987–1996). We used International Classification of Diseases, Ninth Revision codes to identify both circumcisions and complications and limited our analyses to children without other surgical procedures performed during their initial birth hospitalization. Results. Of 354 297 male infants born during the study period, 130 475 (37%) were circumcised during their newborn stay. Overall 287 (.2%) of circumcised children and 33 (.01%) of uncircumcised children had complications potentially associated with circumcision coded as a discharge diagnosis. Based on our findings, a complication can be expected in 1 out every 476 circumcisions. Six urinary tract infections can be prevented for every complication endured and almost 2 complications can be expected for every case of penile cancer prevented. Conclusions. Circumcision remains a relatively safe procedure. However, for some parents, the risks we report may outweigh the potential benefits. This information may help parents seeking guidance to make an informed decision. Pediatrics 2000;105:246–249; newborn circumcision, complications, urinary tract infections. ABBREVIATIONS. UTI, urinary tract infection; NNT, number needed to treat; NNH, number needed to harm; CHARS, Comprehensive Hospital Abstract Reporting System. Routine circumcision of newborn infants remains controversial.1–3 Although a recent policy statement by the American Academy of Pediatrics recommended that parents be given accurate and unbiased information regarding the risks and benefits of the procedure,3 accomplishing this task of well informed consent is hindered both by the lack of precise information about potential harm and by the lack of clear ways to present this information. The benefits of circumcision have been described in numerous previous studies using a variety of methodologies.4–8 Reported benefits include reduction in the risk of penile cancer,9 urinary tract infections (UTIs),4,5 and sexually transmitted diseases.10,11 Although the extent to which circumcision decreases the risk of each of these outcomes has been debated,6,12–15 a consensus appears to be emerging that there are some small protective effects.3 These protective effects of circumcision (or any other therapy) can be meaningfully conveyed in terms of a number needed to treat (NNT). The NNT is calculated from the reciprocal of the absolute risk reduction associated with a given treatment.16 In the case of circumcision, this number represents the number of children who would need to be circumcised to prevent 1 undesired outcome such as UTI. Although NNTs inform both providers and patients of the benefits of a given therapy or procedure, by themselves the NNTs present only half of the pertinent equation. What is also needed to make an informed decision is the number needed to harm (NNH). By analogy to NNTs, NNHs are based on the absolute difference in complication rates between treatment and control groups and tell one in effect how many patients would need to be circumcised before an adverse event can be expected to occur. Taken together, NNTs and NNHs can be used to construct a framework of “tradeoffs”; in essence, one can compute how many undesirable outcomes will be prevented per complication incurred. Trade-offs can be useful to patients and providers seeking to weigh the pros and cons of a given procedure. Although existing data are sufficient to enable us to estimate the NNT with circumcision for given outcomes, the risks of the procedure have received considerably less attention, hindering our ability to calculate NNHs. Previous studies of newborn circumcision complications have reported rates beFrom the *Department of Pediatrics, University of Washington; ‡Child Health Institute, University of Washington; §Robert Wood Johnson Clinical Scholars Program, University of Washington; iDepartment of Health Services, University of Washington, Seattle, Washington. Dr Christakis is a Robert Wood Johnson Generalist Physician Faculty Scholar. Received for publication Jun 9, 1999; accepted Sep 1, 1999. Address correspondence to Dimitri A. Christakis, MD, MPH, Child Health Institute 146 N Canal St, Suite 300, Seattle, WA 98103. E-mail: [email protected] PEDIATRICS (ISSN 0031 4005). Copyright © 2000 by the American Academy of Pediatrics. 246 PEDIATRICS Vol. 105 No. 1 January 2000 by guest on October 3, 2017 http://pediatrics.aappublications.org/ Downloaded from tween .19 and .60%, but because these data were either derived from single institutions or from the children of army recruits they are not populationbased.6,17,18 Therefore we undertook a large, retrospective, population-based cohort study of circumcision of newborn infants. Our goals were threefold: 1) to obtain population-based estimates of complications associated with circumcision; 2) to convert these complication rates into NNHs; and 3) to use these NNHs in conjunction with published data of the benefits of the procedure to develop a framework for presenting NNT versus NNH trade-offs to better inform both practitioners and parents about routine newborn circumcision.