From: Charlson comorbidity index is predictive of postoperative clinical outcome after single-level posterior lumbar interbody fusion surgery
Length of stay (day)
Direct cost (US dollar)
Group 0
20.3
20637.6
Group 1
20.9
21049.3
Group 2+
22.3
21899.3
P value
Group 0–group 1
1
Group 0–group 2+
0.009
0.03
Group 1–group 2+
0.05
0.3