Table 1

Prevalence of major depression and back pain at T-1 by characteristics of the study sample at T-1.

		% in General Sample at T1	Back Pain at T-1 (%)	p	Major Depression at T-1 (%)	p
Health outome
Major depression at T-1				<0.001
	No	89.5	20.8
	Yes	10.5	37.4
Back pain at T-1						<0.001
	No	77.5			8.5
	Yes	22.5			17.4
Demographic characteristic
Age				0.049		<0.001
	30–49	35.0	20.8		13.6
	50–59	28.8	21.8		12.1
	60–75	36.2	24.8		6.2
Sex				0.005		<0.001
	Male	45.5	20.4		6.1
	Female	54.5	24.4		14.1
Race/Ethnicity				0.901		0.731
	Others	8.1	22.8		11.0
	Non-Hispanic White	91.9	22.5		10.4
Socioeconomic status
Education				<0.001		0.01
	High school or less	30.9	27.4		12.3
	Some college	21.0	23.8		11.5
	College and more	48.0	18.9		8.9
Personal earning				<0.001		<0.001
	<$19,999	32.4	29.3		14.1
	$20,000–$59,999	44.2	20.9		9.8
	$60,000–$200,000+	23.0	16.3		6.8
Health behavior
Leisure-time physical activity				<0.001		0.342
	Active	20.0	17.8		9.0
	Insufficiently active	37.0	21.4		10.9
	Inactive	42.0	25.8		10.9
Tobacco use				<0.001		<0.001
	No	85.0	21.2		8.9
	Yes	15.0	30.0		19.6
Alcohol consumption				0.006		0.012
	Non drinkers	40.1	25.3		12.3
	Light to moderate drinkers	45.1	20.9		8.9
	Heavy drinkers	14.8	20.0		10.2
Obesity				<0.001		0.083
	No	68.6	20.4		9.9
	Yes	31.4	27.1		11.8