Table 2

Postoperative patient outcomes for the total cohort and groups stratified by age.

Outcome Measure	Total Cohort (N = 164)	Age <70 y (N = 125)	Age ≥70 y (N = 39)	P
VAS Back Outcomes, median (IQR)
Preoperative	6.0 (4.0–7.5)	6.0 (4.5–7.5)	5.1 (3.3–7.0)	0.060^{^a}
ΔDay 1	1.5 (–0.5 to 3.6)	1.3 (-0.5–3.5)	1.5 (–0.8–3.5)	0.855^{^b}
ΔDay 4	2.0 (0.0–4.5)	2.0 (0.0–4.5)	1.5 (–0.3–4.9)	0.658^{^b}
Δ1 week	2.5 (0.5–4.5)	2.5 (0.5–4.6)	2.5 (0.0–4.2)	0.872^{^b}
Δ2 week	3.0 (1.0–5.0)	3.0 (1.0–5.5)	2.1 (1.0–4.8)	0.699^{^b}
Δ3 month	3.4 (0.8–5.8)	3.5 (1.0–6.0)	2.4 (0.0–5.3)	0.199^{^a}
VAS Ipsilateral Leg Outcomes, median (IQR)
Preoperative	6.2 (4.0–8.0)	6.4 (4.5–8.0)	5.5 (2.0–8.0)	0.140^{^a}
ΔDay 1	3.5 (1.0–6.4)	3.5 (1.0–6.0)	3.0 (0.0–6.8)	0.780^{^b}
ΔDay 4	3.5 (1.0–6.0)	3.5 (1.5–6.0)	2.5 (0.0–6.4)	0.547^{^a}
Δ1 week	3.5 (1.0–6.0)	3.5 (1.5–6.0)	2.5 (0.3–6.8)	0.580^{^a}
Δ2 weeks	3.9 (1.5–6.0)	4.0 (2.0–6.0)	2.0 (0.0–6.3)	0.135^{^a}
Δ3 months	4.2 (2.0–7.0)	4.3 (2.9–6.5)	3.5 (0.0–7.4)	0.428^{^a}
ODI Outcomes, median (IQR)
Preoperative	20.3 (15.2–26.3)	20.3 (15.5–27.0)	20.0 (14.8–24.5)	0.248^{^a}
ΔDay 1	–0.9 (–7.1–7.6)	–1.8 (–8.0–8.0)	1.0 (–5.4–5.0)	0.621^{^a}
ΔDay 4	–1.0 (–6.1–8.0)	0.0 (–6.3–9.0)	–2.3 (–5.0–6.1)	0.325^{^b}
Δ1 week	1.8 (–5.0–9.7)	2.0 (–5.0–10.5)	1.0 (–5.0–7.5)	0.405^{^b}
Δ2 weeks	4.3 (–3.0–10.1)	5.0 (–2.3–11.5)	4.0 (–4.5–6.6)	0.099^{^a}
Δ3 months	11.3 (4.9–18.1)	12.0 (5.3–19.0)	8.3 (3.4–15.3)	0.158^{^b}
Perceived Surgical Outcome at 3 mo, n/N (%)				0.623^{^c}
Good	130/164 (79%)	98/125 (78%)	32/39 (82%)
Poor	34/164 (21%)	27/125 (22%)	7/39 (18%)

Abbreviations: IQR, interquartile range; ODI, Oswestry Disability Index; VAS, visual analog scale.
Note: “Δ” Values are reported as the median change in score from preoperative evaluation to the indicated follow-up time point. Positive values represent an improvement and negative values represent a decline.
↵a Wilcoxon rank sum test.
↵b Two sample t test.
↵c Pearson’s χ ² test.