Table 2:

Sample characteristics

Variable	No.^{^a}	Patients with LBP (240 Subjects)	No.^{^a}	Subjects without LBP (64 Subjects)
Age (range) (yr)^{^b}	240	43 (38–47)	64	45 (41–47)
Sex^{^c}	240		64
Male (median)		108 (45)		35 (54.7)
Female (median)		132 (55)		29 (45.3)
BMI (range) (Kg/m²)^{^b}	228	24.6 (22.4–27.3)	60	25.2 (21.9–27.4)
Lifetime smoking (pack-years) (range)^{^b}	224	2.3 (0.0–11.2)	60	3 (0–11)
Highly intense physical activity (median)^{^c}	199	51 (25.6)	48	9 (18.8)
Low back pain severity (VAS) (range)^{^b}	229	4 (2–7)	52	0 (0–0)
Duration of pain (range) (mo)	185	46 (11–112)	64
Disability (range) (RMQ)^{^b}	213	6 (3–12)	6	1 (1–1)
Vertebral endplate changes (any type)^{^c,^d}	240	193 (80.4)	64	56 (87.5)
Types of vertebral endplate changes^{^c}	193		56
Only type I		10 (4.2)		1 (1.6)
Types I and II		38 (15.8)		14 (21.9)
Types I and III		2 (0.8)		0 (0.0)
Type I, II, and III		11 (4.6)		0 (0.0)
Only type II		120 (50.0)		40 (62.5)
Types II and III		11 (4.6)		0 (0.0)
Only type III		1 (0.4)		1 (1.6)
No. of vertebral endplate changes per patient^{^b}	240	2 (1; 3)	64	3 (2; 4)
Severe disk degeneration^{^c}	240	158 (65.8)	64	30 (46.9)

↵a No. of subjects in each group for whom data on the corresponding variable were available (subjects who answered the corresponding question or in whom the variable was applicable—eg, age, sex, weight, height, patients who showed any type of vertebral endplate change or severe disk degeneration, and so forth).
↵b Median (P25, P75).
↵c No. (%).
↵d P value for the comparison of the proportion of vertebral endplate changes among subjects without LBP, compared with those with LBP: .191.