. Author manuscript; available in PMC: 2010 Oct 19.

Published in final edited form as: Pain. 2006 May 15;124(1-2):150–157. doi: 10.1016/j.pain.2006.04.008

Table 2.

The association of the Impact of Event Scale and chronic widespread pain in monzygotic and dizygotic twins

Impact of Event Scale	All Twins		Monozygotic Twins		Dizygotic Twins
Impact of Event Scale	Odds Ratio	95% CI^a	Odds Ratio	95% CI	Odds Ratio	95% CI
Tercile 1^b	1.0	--	1.0	--	1.0	--
Tercile 2	2.4	1.6–3.7	2.3	1.3–4.1	2.6	1.4–4.9
Tercile 3	3.5	2.3–5.3	3.8	2.2–6.6	3.1	1.7–5.9
	P_trend < 0.0001		P_trend < 0.0001		P_trend < 0.0001

CI = confidence interval;

Impact of Event Scale score tercile ranges: tercile 1 = 0–6; tercile 2 = 7–24; tercile 3 = 25+