. Author manuscript; available in PMC: 2010 May 25.

Published in final edited form as: Arch Intern Med. 2009 May 25;169(10):972–981. doi: 10.1001/archinternmed.2009.78

Table 4.

Clinical events among Medicare beneficiaries within 180 days after diagnosis of acute low back pain, by the rapidity and modality of imaging they received

Rapidity and Modality of Imaging	Total (100%)	New Diagnoses of Cancer N (%)	Hospitalizations for Back Diagnoses N (%)	Complications or Progression of Back Pain N (%)
No imaging	22,745	1,511 (7.3)	22 (0.1)	28 (0.2)
Rapidity
29-180days	1,657	64 (3.9)^b	69 (4.3)^b	29 (2.3)^b
Within 28 days	9,637	651 (5.8)^a	288 (2.5)^b	111 (1.0)^b
Modality
Radiograph only	7,696	474 (5.3)^a	65 (0.7)^b	31 (0.3)^a
CT/MRI	3,598	241 (6.0)^a	292 (7.3)^b	109 (2.9)

Unweighted counts and weighted percentages are based on analysis of claims in years 2000-2002 and 2004-2006 for 35,039 fee-for-service Medicare beneficiaries treated by one of 4,567 primary care physician respondents to the Community Tracking Study Physician Survey. P-values reflect comparisons to beneficiaries who did not receive imaging.

p<0.05

p<0.001