Errors in Text and Conversion Factors. In the Article titled “Validation and Refinement of a Prediction Rule to Identify Children at Low Risk for Acute Appendicitis” by Kharbanda et al, published in the August issue of the Archives (2012;166[8]:738-744), errors occurred in the text and in conversion factors given in the text, 3 table footnotes, and 2 figure legends. In the text, on page 739, the last sentence in the right-hand column (which continues onto page 740) should have read: “The following variables were entered: duration of abdominal pain, nausea, emesis, history of focal RLQ pain, presence of abdominal tenderness, maximal tenderness in the RLQ, abdominal pain with walking, abdominal pain on the right side with walking, and the absolute neutrophil and white blood cell counts using both continuous and categorical cutoff points.” Also on page 739, the first sentence of the “Data Analysis” subsection should have read as follows: “The previously published low-risk prediction rule consisted of the following variables: absolute neutrophil count of 6.75 × 103/μL or less (to convert the count to ×109 per liter, multiply by 1), absence of nausea, and absence of maximal tenderness in the right lower quadrant (RLQ) of the abdomen.” On page 741, the second footnote to Table 1 should have appeared as: “SI conversion factor: To convert WBC count to ×109 per liter, multiply by 1.” On pages 741 and 742, the second footnote to Tables 3 and 4 should have appeared as: “SI conversion factor: To convert ANC to ×109 per liter, multiply by 1.” Also on those pages, the second sentence of the legends to Figures 2 and 3 should have read: “ANC indicates absolute neutrophil count (to convert count to ×109 per liter, multiply by 1); RLQ, right lower quadrant.”