Copyright © 2017 International Anesthesia Research Society. Unauthorized reproduction of this article is prohibited. XXX 2017 • Volume XXX • Number XXX www.anesthesia-analgesia.org 1 DOI: 10.1213/ANE.0000000000002681 KEY POINTS • Question: Is perioperative steroid use associated with an increased incidence of reoperation for posttonsillectomy bleeding? • Findings: There was no signifcant association between perioperative steroid use and reopera- tion for bleeding with the incremental risk of reoperation within an acceptable range. • Meaning: Our results support the safety of perioperative steroid use for tonsillectomy. T here is evidence that dexamethasone reduces post- tonsillectomy complications, such as nausea and vomiting, pain, and delayed recovery. 1,2 Guidelines recommend intraoperative administration of dexametha- sone for tonsillectomy in both children and adults to reduce postoperative complications 3,4 ; however, there are ongoing concerns that intraoperative dexamethasone may increase the risk of reoperation for posttonsillectomy hemorrhage, and conficting results have been reported regarding this issue even after the publication of the guidelines. One ran- domized controlled trial indicated that dexamethasone use increases the risk of posttonsillectomy bleeding. 5 Conversely, a noninferiority trial concluded that dexa- methasone use has no association with an increased risk of reoperation for bleeding. 6 However, this trial was criti- cized for setting the same noninferiority margin at 5% for all kinds of bleeding, including any bleeding, bleeding requir- ing rehospitalization, and bleeding requiring reoperation. 7 Several meta-analyses have also concluded that there is no signifcant increase in posttonsillectomy bleeding inci- dence in patients administered dexamethasone, 8–11 but one of these did report an increased incidence of reintervention BACKGROUND: Steroids reduce postoperative complications after tonsillectomy such as nau- sea and vomiting, pain, and delayed recovery. However, steroids may also increase the risk of severe posttonsillectomy bleeding requiring reoperation. METHODS: To evaluate the risk of postoperative bleeding requiring reoperation related to peri- operative steroid use, we conducted a retrospective cohort study of 6149 patients treated at 68 hospitals using a hospital-based claims database. The primary outcome was reoperation for bleeding within 14 postoperative days. We estimated odds ratios (ORs) between periopera- tive steroid use and reoperation by multivariable logistic regression analysis adjusted for con- founders. We also estimated differences in the adjusted risk. Subgroup analyses after dividing patients into adults and children were also performed. RESULTS: The incidence of reoperation did not differ signifcantly between patients who received steroids on the day of tonsillectomy and those who did not (1.8%, n = 15 vs 1.5%, n = 79; adjusted OR 0.81, 95% confdence interval [CI], 0.45–1.43; P = .46). We also found nonsignif- cant associations in both adults (OR, 0.73; 95% CI, 0.38–1.38; P = .33) and children (OR, 1.18; 95% CI, 0.34–4.11; P = .80). The adjusted risk differences estimated by the logistic regression model were −0.30% (95% CI, −1.05 to 0.45) in all patients, −0.64% (95% CI, −1.82 to 0.54) in adults, and 0.13% (95% CI, −0.93 to 1.19) in children. CONCLUSIONS: Steroid use on the day of tonsillectomy was not associated with an increased risk of reoperation for bleeding. Although the wide range of CIs for the ORs could not eliminate the possibility of increased risk, especially in children, the incremental risks of reoperation for steroid use were within an acceptable range for both adults and children. Our results support the safety of perioperative steroid use for tonsillectomy, considering the magnitude of risk of reoperation because of bleeding. (Anesth Analg 2017;XXX:00–00) Perioperative Steroid Use for Tonsillectomy and Its Association With Reoperation for Posttonsillectomy Hemorrhage: A Retrospective Cohort Study Yoshihisa Miyamoto, MD, MPH, Maki Shinzawa, MD, PhD, Shiro Tanaka, PhD, Sachiko Tanaka-Mizuno, PhD, and Koji Kawakami, MD, PhD From the Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Kyoto, Japan. Accepted for publication October 20, 2017. Funding: Support was provided solely from institutional and/or departmen- tal sources. Conficts of Interest: See Disclosures at the end of the article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.anesthesia-analgesia.org). Yoshihisa Miyamoto, MD, MPH, is currently affliated with the Department of Anesthesia, Kanagawa Children’s Medical Center, Yokohama, Japan. Maki Shinzawa, MD, PhD, is currently affliated with the Department of Nephrology, Graduate School of Medicine, Osaka University, Suita, Japan. Shiro Tanaka, PhD, is currently affliated with the Department of Clinical Biostatistics, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Sachiko Tanaka-Mizuno, PhD, is currently affliated with the Department of Medical Statistics, Shiga University of Medical Science, Otsu, Japan. Reprints will not be available from the authors. Address correspondence to Koji Kawakami, MD, PhD, Department of Phar- macoepidemiology, Graduate School of Medicine and Public Health, Kyoto University, Yoshidakonoecho, Sakyo-ku, Kyoto 606–8501, Japan. Address e- mail to kawakami.koji.4e@kyoto-u.ac.jp. Copyright © 2017 International Anesthesia Research Society