Why does the adverse effect of inappropriate MRI for LBP vary by geographic location? An exploratory analysis

Table 1 Cohort characteristics according to individual and state-level variables

Variable	Number	Percentage	Mean (minimum, maximum)	SD
Gender
Female	18,352	30.9
Male	41,008	69.1
Age (years)			39.4	10.8
Tenure (years)			5.8	7.7
Average Weekly Wage ($)			403.0	187.5
Injury Severity
Less severe	47,805	80.5
More severe	11,555	19.5
Early opioid prescribing (MEA per 100 mg)
No	43,013	72.5
Yes	16,347	27.5	3.9	3.8
Early lumbar MRI scan
No	41,805	70.4
Yes	17,555	29.6
Lumbar spine surgery
No	53,869	90.7
Yes	5491	9.3
Industry type
Mining	1071	1.8
Construction	2087	3.5
Transportation, Communications, Electric, Gas, and Sanitary Services	16,305	27.5
Agriculture, Forestry, and Fishing	588	1.0
Manufacturing	10,887	18.3
Wholesale Trade	4515	7.6
Retail Trade	6626	11.2
Services	14,782	24.9
Public Administration	1990	3.4
Finance, Insurance, and Real Estate	509	0.9
Litigation status
Yes	19,182	32.3
No	40,178	67.7
Median household income ($K)			52.7	21,394
Wage replacement rate (%)			68	3
Waiting period (days)			5.3	1.9
Retroactive period (days)			15.7	7.0
State medical fee schedule
No	10,498	17.7
Yes	48,862	82.3
Initial treating provider choice
Allowed	22,516	37.9
Not allowed	36,844	62.1
Treating provider change
Allowed	8282	14.0
Allowed once	14,241	24.0
Not Allowed	36,837	62.1
Annual unemployment rate			5.3	1.0
Annual number of state active Orthopedic surgeons per 100,000 population in 2004 and 2006			6.3	0.99
Annual number of state active physicians per 100,000 population			272.1	66.6
Number of state MRI facilities per 100,000 population in 2006			2.4	0.62

ISSN: 1471-2474