Increasing substance P levels in serum and synovial tissues from patients with developmental dysplasia of the hip (DDH)

Table 2 Correlation test of serum SP levels with HHS, VAS and ESR in patients with DDH and DDH&OA

Correlation of serum substance P levels
Group	Sex	N	With HHS		With VAS		With ESR
Group	Sex	N	R	P	R	P	R	P
DDH
	F	30	−0.344	0.063	0.216	0.251	0.086	0.652
	M	10	−0.820	<0.01*	0.591	0.072	0.407	0.243
	F + M	40	−0.219	0.175	0.349	0.027	0.156	0.336
DDH&OA
	F	27	−0.384	0.048	0.355	0.069	0.497	0.083
	M	13	−0.694	<0.01*	0.428	0.144	0.437	0.135
	F + M	40	−0.496	<0.01*	0.512	<0.01*	0.508	<0.01*

F female, M male, N number, R correlation coefficient. Spearman correlation test was implemented to investigate the possible correlations in separate groups. A two sides *P < 0.01 means significant correlation.