FIGURE 3.

Effect of perioperative music on postoperative opioid requirement. Forest plot presenting the effect of perioperative music on postoperative opioid requirement (milligrams of morphine equianalgesics). CI indicates confidence interval; Mean, mean milligrams of morphine equianalgesics; N, total number of patients in study; N_C, number of patients in the control group; N_M, number of patients in the music group; PACU, post-anesthesia care unit; SD, standard deviation in milligrams of morphine equianalgesics; SMD, standardized mean difference.