Independent variable		Back pain lifetime				p-value
		No		Yes
		n	%	n	%
Gender	Female	53	27	143	73	0.002
Gender	Male	34	47.2	38	52.8
Age (years)	20 - 29	13	50	13	50	0.009
	30 - 39	39	41.9	54	58.1
	40 - 49	25	23.6	81	76.4
	50 - 59	9	22	32	78
	60 - 69	1	50	1	50
Marital status	Married	43	27.2	115	72.8	0.015
	Single	43	43.4	56	56.6
	Divorced	0	0	5	100
	Widow	1	16.7	5	83.3
Tobacco c.	Yes	1	50	1	50	0.595
	No	86	32.3	180	67.7
Chronic disease	Yes	7	20	28	80	0.091
	No	80	34.3	153	65.7
Family history	Yes	30	24	76	95	0.006
	No	57	39.9	86	60.1
BMI	Underweight	0	0	2	100	0.230
	Normal weight	27	39.1	42	60.9
	Overweight	40	33.9	78	66.1
	Obese	20	25.3	59	74.7
Stress level	Low	25	49	26	51	0.019
	Moderate	55	28.9	135	71.1
	High	7	25.9	20	74.1
Physical activity	Low	63	37.3	106	62.7	0.020
	Moderate	13	18.8	56	81.2
	High	11	36.7	19	63.3