Table 3.

Summary of findings.

Outcomes	Primary Analysis	RCT Subgroup	Grade I Spondylolisthesis	Single-Vertebral Level Surgery
Oswestry Disability Index	MD 4.04 [0.95, 7.13], P = 0.01; I 2: 80%	MD 1.78 [−10.34, 13.91], P = 0.77; I 2: 80%	MD 6.48 [1.17, 11.79], P < 0.001; I 2: 72%	MD 4.15 [1.48, 6.82], P = 0.002; I 2: 0%
MCID ODI	OR 0.76 [0.57, 1.07], P = 0.12; I 2: 0%	Insufficient data	Insufficient data	Insufficient data
Back pain	SMD 0.27 [0.00, 0.53], P = 0.05; I 2: 90%	Insufficient data	SMD 0.26 [−0.58, 1.10], P = 0.55; I 2: 95%	SMD 0.15 [−0.20, 0.51], P = 0.39; I 2: 76%
Leg pain	SMD 0.13 [0.06, 0.21], P < 0.001; I 2: 0%	Insufficient data	SMD 0.02 [−0.17, 0.20], P = 0.86; I 2: 0%	SMD 0.13 [−0.02, 0.28], P = 0.08; I 2: 0%
Complications	OR 0.60 [0.34, 1.04], P = 0.07; I 2: 35%	OR 0.49 [0.11, 2.23], P = 0.36; I 2: 68%	OR 0.77 [0.45, 1.33], P = 0.35; I 2: 0%	OR 0.42 [0.09, 1.94], P = 0.27; I 2: 37%
Reoperation	OR 1.17 [0.71, 1.93], P = 0.54; I 2: 52%	OR 1.39 [0.33, 5.93], P = 0.66; I 2: 80%	Insufficient data	Insufficient data
Duration of surgery	MD −85.18 min [−122.79, −47.57], P < 0.001; I 2: 99%	MD −104.40 min [−168.75, −40.04], P = 0.001; I 2: 96%	MD −81.21 min [−129.40, −33.03], P = 0.001; I 2: 98%	MD −115.38 min [−160.05, −70.71], P < 0.001; I 2: 91%
Blood loss	MD −262.65 mL [−313.45, −211.85], P < 0.001; I 2: 87%	MD −345.00 mL [−458.89, −231.11], P < 0.001; I 2: 71%	MD −267.15 mL [−326.17, −208.14], P < 0.001; I 2: 90%	MD −277.09 mL [−395.15, −159.03], P < 0.001; I 2: 89%
Length of hospital stay	MD −2.64 d [−3.58, −1.70], P < 0.001; I 2: 91%	MD −2.14 d [−3.12, −1.16], P < 0.001; I 2: 49%	MD −2.09 d [−2.69, −1.49], P < 0.001; I 2: 62%	MD −2.03 d [−2.62, −1.44], P < 0.001; I 2: 70%

Data in brackets represent 95% CIs.