Table 2.

Correlations between predictor variables and symptom severities

Predictor variables		PTSD symptom severities (PDS)		Depressive symptom severities (BDI)
	M (SD) or N (%)	2 weeks	6 months	2 weeks	6 months
Cortisol (nmol/l)1
in emergency room	12.18 (10.51)	− 0.33⁎2	− 0.33⁎2	− 0.052	− 0.45⁎⁎2
day after MVA 8 am	12.45 (4.81)	0.21	0.12	− 0.25	− 0.01
day after MVA 10 pm	4.40 (3.89)	0.17	0.17	0.00	0.06
6-month FU 8 am	13.19 (5.32)	N/I	− 0.10	N/I	− 0.07
6-month FU 10 pm	5.44 (8.83)	N/I	0.40⁎	N/I	0.42⁎
Cardio-vascular variables
Heart rate (bpm) taken from hospital notes	74.97 (15.70)	− 0.18	− 0.17	0.29	0.11
Mean resting heart rate (bpm) during assessment	72.93 (11.16)	− 0.22	− 0.15	0.14	0.06
Systolic blood pressure (mmHg)	125.94 (14.71)	− 0.25	− 0.20	0.14	− 0.03
Diastolic blood pressure (mmHg)	72 (14.64)	− 0.42⁎	− 0.37⁎	− 0.08	− 0.18
Questionnaire results
Past emotional problems3	Yes: 25 (47.2%) No: 28 (52.8%)	0.25	0.36⁎	0.20	0.56⁎⁎
Number of past traumas	2.40 (2.27)	0.11	0.13	0.10	0.33⁎
Pain in emergency room	4.03 (2.54)	0.36⁎	0.27	0.44⁎⁎	0.26
Pain severity at 6 months	.33 (1.23)	N/I	0.31	N/I	0.41⁎
Perceived threat to life	2.89 (2.81)	.34⁎	0.16	− 0.01	0.16
Fear	9.39 (5.16)	0.42⁎⁎	0.18	− 0.01	0.06
Helplessness	8.00 (4.77)	0.48⁎⁎	0.19	0.09	0.06
Guilt/shame	1.18 (1.96)	0.37⁎⁎	0.24	0.01	0.17
Anger	3.80 (3.02)	0.24	− 0.04	0.16	− 0.08
Dissociation	6.83 (7.49)	0.48⁎⁎	0.29⁎	0.01	0.18
Data-driven processing	8.95 (7.12)	0.54⁎⁎	0.32⁎	− 0.02	0.27

MVA: motor vehicle accident; FU: follow-up; ^⁎P < 0.05; ^⁎⁎P < 0.01; N/I: not of interest for the hypotheses tested.

¹Cortisol levels were not significantly correlated with the Body Mass Index, injury severity, cigarettes smoked per day, alcohol units consumed in past week, drug use in past week and anti-depressant medication taken or time elapsed since the accident.

²Time of day partialled out.

³Correlations in this row are point-biserial correlation coefficients.