Table 5.

Factors Associated With Arterial Testing Before Amputation

VariableUnadjusted RR (95% CI)P ValueAdjusted RR (95% CI)P Value
Age group, y
 <500.80 (0.75–0.86)<0.0010.78 (0.73–0.83)<0.001
 50–540.94 (0.88–1.00)0.070.90 (0.84–0.95)<0.001
 55–590.96 (0.91–1.01)0.110.91 (0.86–0.95)<0.001
 60–641.02 (0.97–1.06)0.450.95 (0.91–0.99)0.03
 65–691.03 (0.99–1.07)0.120.99 (0.96–1.03)0.70
 70–741.03 (0.99–1.06)0.131.01 (0.98–1.05)0.39
 75–791.00 (Reference)1.00 (Reference)
 80–840.99 (0.96–1.03)0.741.02 (0.99–1.06)0.17
 85–890.98 (0.94–1.02)0.301.03 (1.00–1.07)0.09
 ≥900.90 (0.85–0.94)<0.0010.98 (0.94–1.04)0.54
Women0.91 (0.89–0.93)<0.0010.91 (0.89–0.93)<0.001
Race
 Black1.10 (1.07–1.12)<0.0011.10 (1.08–1.13)<0.001
 White1.00 (Reference)1.00 (Reference)
 Other1.07 (1.03–1.12)0.0021.08 (1.03–1.13)<0.001
Comorbid conditions
 Cancer1.04 (1.01–1.07)0.020.98 (0.95–1.01)0.27
 Cerebrovascular disease1.11 (1.09–1.14)<0.0011.04 (1.02–1.06)<0.001
 Chronic obstructive pulmonary disease1.09 (1.07–1.11)<0.0011.03 (1.01–1.05)0.01
 Congestive heart failure1.16 (1.13–1.18)<0.0011.02 (1.00–1.04)0.08
 Dementia0.90 (0.86–0.94)<0.0010.87 (0.84–0.91)<0.001
 Diabetes mellitus1.20 (1.17–1.22)<0.0011.09 (1.06–1.12)<0.001
 Hypertension1.18 (1.15–1.22)<0.0011.03 (1.00–1.06)0.07
 Ischemic heart disease1.19 (1.17–1.22)<0.0011.04 (1.02–1.07)0.001
 Peripheral arterial disease1.19 (1.16–1.21)<0.0011.10 (1.07–1.12)<0.001
 Renal disease1.21 (1.19–1.24)<0.0011.10 (1.08–1.13)<0.001
Outpatient evaluation and management visit1.20 (1.18–1.23)<0.0011.09 (1.06–1.11)<0.001
Rural location0.92 (0.90–0.95)<0.0010.95 (0.93–0.97)<0.001
US Census region
 East North Central1.07 (1.04–1.10)<0.0011.07 (1.04–1.10)<0.001
 East South Central0.96 (0.92–1.00)0.030.99 (0.95–1.03)0.65
 Middle Atlantic1.07 (1.03–1.10)<0.0011.05 (1.02–1.09)0.002
 Mountain0.82 (0.76–0.88)<0.0010.85 (0.80–0.91)<0.001
 New England0.95 (0.90–1.00)0.070.95 (0.90–1.01)0.09
 Pacific0.95 (0.91–0.99)0.010.96 (0.92–1.00)0.045
 South Atlantic1.00 (Reference)1.00 (Reference)
 West North Central0.94 (0.90–0.99)0.011.00 (0.95–1.04)0.94
 West South Central1.01 (0.97–1.04)0.691.02 (0.98–1.05)0.38
Year of index amputation
 20021.00 (Reference)1.00 (Reference)
 20031.01 (0.97–1.05)0.690.99 (0.95–1.04)0.80
 20041.03 (0.98–1.07)0.241.02 (0.98–1.06)0.35
 20051.07 (1.03–1.12)<0.0011.05 (1.01–1.10)0.01
 20061.06 (1.02–1.11)0.0041.04 (1.00–1.09)0.05
 20071.04 (1.00–1.09)0.051.03 (0.98–1.07)0.22
 20081.05 (1.01–1.10)0.0201.04 (1.00–1.09)0.05
 20091.07 (1.03–1.12)0.0011.05 (1.01–1.09)0.03
 20101.05 (1.01–1.10)0.021.03 (0.99–1.07)0.18
  • CI indicates confidence interval; and RR, risk ratio.