. Author manuscript; available in PMC: 2011 Nov 1.

Published in final edited form as: Comput Human Behav. 2010 Nov 1;26(6):1327–1335. doi: 10.1016/j.chb.2010.04.006

Table 3.

Differences Between Phone and Online Samples in Indicators of Mental Health

	Online (n = 265) M (SD) or %	Phone (n = 255) M (SD) or %	χ² or t
Alcohol and Substance Use/Abuse
Alcohol Use in Past Year	82.4%	90.3%	6.34^**
Alcohol Abuse Ever	30.9%	38.0%	2.90
Alcohol Abuse in Past Year	1473%	14.5%	0.004
Substance Use Ever	45.7%	55.7%	5.23^**
Any Substance Use in Past Year	11.7%	14.1%	0.68
Nonexperimental Use in Past Year	6.4%	7.5%	0.22

PTSD
Scored Above Clinical Cut-Off	4.5%	1.6%	3.82^*
PCL Total Score	21.13 (9.37)	19.70 (6.91)	1.98^*
PCL Re-Experiencing	6.69 (3.28)	6.43 (2.58)	1.02
PCL Avoidance	8.14 (3.80)	7.52 (2.95)	2.10^*
PCL Hyperarousal	6.30 (2.98)	5.76 (2.07)	2.41^*

Social Support	22.34 (5.89)	25.18 (3.99)	6.48^***

p < .05,

^**

p < .01,

^***

p < .001.