Table 4.

Correlation coefficients between plasma creatine kinase and cell‐free DNA

	Spearman's Rank Correlation ρ	P Value	Kendall's Rank Correlation τ	P Value
All surgery	0.53	0.003	0.38	0.003
All surgery 6–72 hours	0.47	0.040	0.35	0.030
HL surgery 6–72 hours	0.96	0.003	0.9	0.003

HL, hemilaminectomy.