Table 1

	Group				X² Test	p-value
	Study (n=30)		Control (n=30)
	No.	%	No.	%
Age (years):>
<40	17	56.7	23	76.7
40+	13	43.3	7	23.3	2.70	0.10
Range	22.0-55.0		22.0-50.0
Mean±SD	38.1±10.4		33.8±8.8
Sex:
Male	14	46.7	17	56.7
Female	16	53.3	13	43.3	0.60	0.44
Past history of:
Recurrent tension headache	17	56.7	16	53.3	0.07	0.80
Abdominal surgery	14	46.7	18	60.0	1.07	0.30

Table 1: Demographic characteristics and medical history of patients in the study and control groups.