A prediction formula was constructed using multivariate logistic regression based on significant factors, including smoking, gout medication use, preoperative Hb level, and Hb drop, as follows: PY=1=e3.8 − 1.2Med + 1.3smoking − 0.4preOP Hb + 0.7Hb drop1+e3.8 − 1.2Med + 1.3smoking − 0.4preOP Hb + 0.7Hb drop. Here, GSTM1 is linked to gout.