Table 4.

Improvements from preoperatively to 1-year postoperatively in VAS as an estimation of back and leg pain, EuroQol and SF-36 as estimations of quality of life, and ODI as an estimation of disability. Data are mean (95% CI) or percentages. Elderly is defined as those aged ≥65 years, and younger refers to the sex-matched comparison group aged 20–64

	Improvement by surgery
	Elderly	Younger	p-value
VAS back pain	27 (25–29)	22 (21–23)	0.003
VAS leg pain	40 (38–42)	45 (44–46)	< 0.001
EuroQol-index	0.42 (0.40–0.45)	0.45 (0.44–0.46)	< 0.05
EuroQol-VAS	22 (20–24)	26 (26–27)	< 0.001
SF-36
PF	29 (27–31)	36 (36–37)	< 0.001
RP	42 (39–45)	51 (50–52)	< 0.001
BP	37 (35–39)	39 (38–40)	0.03
GH	2 (0–3)	2 (1–2)	0.8
VT	22 (20–24)	25 (24–25)	0.008
SF	31 (29–33)	34 (33–34)	0.02
RE	33 (30–37)	33 (32–34)	0.7
MH	15 (14–16)	16 (15–16)	0.3
PCS	9 (8–10)	10 (10–10)	0.03
MCS	12 (11–12)	13 (13–13)	0.004
ODI	28 (26–29)	29 (29–29)	0.1
Satisfaction, %			0.04
Satisfied/indeterminate	91	92
Dissatisfied	9.3	7.6

For Abbreviations, see Table 3.