Table 2.

Unadjusted Health Care Costs and Utilization by Imaging Category

	Adherence to Clinical Practice Guidelines That Advise Against Early MRI for Patients without “Red Flags”
	Nonadherent (N = 336)	Adherent (N = 1434)	p-value
Any utilization of services, %
MRI	100.0	17.8	<.001
CT	5.4	3.1	.048
Radiograph	30.4	18.1	<.001
Injection	40.8	6.9	<.001
Surgery	19.9	2.5	<.001
Number of visits, mean (SD)*
Chiropractic	14.7 (28.1)	13.9 (24.2)	.641
PT/OT	18.4 (19.9)	6.8 (13.8)	<.001
Outpatient	12.2 (8.0)	4.3 (6.1)	<.001
Costs, mean (SD)*†
Outpatient services	$7,583 (5,147)	$2,807 (4,084)	<.001
Inpatient services	1,702 (2,445)	388 (1,077)	<.001
Non-medical‡	2,425 (3,347)	670 (2,062)	<.001
Disability compensation	10,442 (10,916)	2,775 (6,089)	<.001
Total costs	22,151 (17,092)	6,640 (11,019)	<.001

^*Mean number of visits and mean costs include all workers, including nonusers and those with zero costs.

^†Costs refer to total reimbursed amounts for procedures and visits that occurred within 1 year following injury, inflation adjusted to 2005 equivalents, based on Medical Consumer Price Index.

^‡Nonmedical costs include reimbursement for vocational (return-to-work) assistance or rehabilitation, employability assessments, worker transportation, medical devices, and other costs not included in other cost categories.

Nonadherent group reflects workers who received an MRI within the first 6 weeks of injury. Adherent group reflects workers who received an MRI after the first 6 weeks of injury (N = 255) or did not receive an MRI at all (N = 1,179).

Values are counts (percentages) and unadjusted means (SD) as indicated. p-values indicate unadjusted comparison using chi-squared or t-tests.

CT, computed tomography (lumbar); MRI, magnetic resonance imaging (lumbar); PT/OT, physical therapy or occupational therapy.