Table 3. Medications prescribed in the year prior to surgery stratified by Anatomical Therapeutic Chemical Level One Class.

Anatomical Therapeutic Chemical Level One Class	Total number of patients prescribed at least one medication (%, n=9,741)	Mean number of prescription medications per patient (standard deviation)
A: alimentary tract and metabolism	6,254 (64.2)	1.17 (1.2)
B: blood and blood forming organs	3,160 (32.4)	0.43 (0.7)
C: cardiovascular system	8,050 (82.6)	2.56 (2.0)
D: dermatologics	3,359 (34.5)	0.59 (1.0)
G: genitourinary system and sex hormones	3,861 (39.6)	0.57 (0.8)
H: systemic hormonal preparations	2,281 (23.4)	0.27 (0.5)
J: anti-infective for systemic use	4,899 (50.3)	1.02 (1.4)
L: antineoplastic and immunomodulating agents	574 (5.9)	0.07 (0.3)
M: musculoskeletal system	3,698 (38.0)	0.53 (0.8)
N: nervous system	7,468 (76.7)	2.50 (2.3)
P: antiparasitic products, insecticides, and repellents	101 (1.0)	0.01 (0.1)
R: respiratory system	6,289 (64.6)	2.02 (2.2)
S: sensory organs	999 (10.3)	0.17 (0.6)
V: various	1,669 (17.1)	0.17 (0.4)