Table 5.

Mixed effect model estimates

	Estimate (P values)
	SDNN	RMSSD	pNN50	HF	HFnu
Trajectory of time
Baseline value	0.160 (<0.001)*	0.186 (<0.001)*	0.196 (0.0002)*	0.271 (0.103)	0.238 (<0.001)*
Days postinjury	−0.0001 (0.712)	0.0001 (0.020)*	0.0009 (0.029)*	0.001 (0.005)*	0.0008 (<0.001)*
Effect of symptom domains in concussed individuals
PCSI—Physical	NS	NS	0.0157 (0.019)*	0.064 (<0.001)*	0.014 (<0.001)*
PCSI—Cognitive	NS	NS	0.023 (0.012)*	0.138 (<0.001)*	0.033 (<0.001)*
PCSI—Emotional	NS	NS	0.035 (0.101)	0.305 (<0.001)*	0.069 (<0.001)*
PCSI—Fatigue	NS	NS	0.028 (0.030)*	0.131 (<0.001)*	0.022 (0.003)*
Symptom status† (symptomatic vs asymptomatic)	NS	NS	NS	NS	NS
Concussed vs controls
Injury status‡ (concussed vs control)	−0.044 (0.524)	−0.143 (0.058)	NS	0.101 (<0.001)*	NS

*Denotes a significant main effect where p<0.05.

†Symptom status refers to symptomatic vs asymptomatic.

‡Injury status refers to concussed vs control.

‘NS’ denotes a non-significant effect; PCSI, Post-Concussion Symptom Inventory.