Shirakami et al. (A-42) investigated the clinical significance of endothelin (ET), natriuretic peptides, and the renin-angiotensin-aldosterone system in pediatric liver transplantation. Subjects were children ages 6 months to 12 years undergoing living-related liver transplantation due to congenital biliary atresia and severe liver cirrhosis. Among the data collected were the following serum total bilirubin (mg/dl) levels after transplantation (h–hours, d–days):

Time After Reperfusion of Donor Liver Preoperative Liver Transection Anhepatic Phase 1 h 2 h 4 h 8 h 1 d 2 d 3 d 6.2 1.2 0.9 0.8 1.1 1.5 2 1.4 1.6 1.3 17.6 11.9 9.3 3.5 3 6.1 9 6.3 6.4 6.2 13.2 10.2 7.9 5.3 4.9 3.3 3.6 2.8 1.9 1.9 3.9 3.3 3 2.9 2.3 1.4 1.2 0.8 0.8 0.9 20.8 19.4  9.4 8.4 6.8 7.1 3.7 3.8 3.2 1.8 1.8 1.6 1.4 1.4 1.1 1.9 0.7 0.8 0.7 8.6 6.5 4.8 3.1 2.1 1 1.3 1.5 1.6 3.2 13.4 12 10.1 5.8 5.6 4.5 4.1 3 3.1 3.6 16.8 13.9 8.3 3.7 3.7 2.2 2.1 1.9 3.1 4.1 20.4 17.8 17 10.8 9.3 8.9 7 2.8 3.8 4.8 25 21.5 13.8 7.6 7 5 11.5 12.3 10.1 11.4 9.2 6.3 6.8 5.3 4.8 0.2 4 4.2 3.7 3.5 8 6.5 6.4 4.1 3.8 3.8 3.5 3.1 2.9 2.8 2.9 3 4.1 3.4 3.4 3.7 4.2 3.3 2 1.9 21.3 17.3 13.6 9.2 7.9 7.9 9.8 8.6 4.7 5.5 25 25 24 20.1 19.3 18.6 23.6 25 14.4 20.6 23.3 23.7 15.7 13.2 11 9.6 9.3 7.2 6.3 6.3 17.5 16.2 14.4 12.6 12.7 11.5 10 7.8 5.5 4.9

 Missing observation.

Source: Data provided courtesy of Dr. Gotaro Shirakami.

Note that there is a missing observation in the data set. You may handle this problem in at least three ways.

(a) Omit the subject whose datum is missing, and analyze the data of the remaining 17 subjects.

(b) Use a computer package that automatically deals with missing data.

(c) Analyze the data using a missing data procedure. For such a procedure, see Jerome L. Myers and Arnold D. Well, Research Design and Statistical Analysis, Erlbaum Associates, Hillsdale, NJ, 1995, pp. 256–258.