Table 2 Utilization of radiology modalities per 1,000 person-years

X-ray

379

570

0.66

0.65–0.68

<0.001

 Ambulatory care

329

493

0.67

0.65–0.69

<0.001

 Inpatient care

50

77

0.65

0.60–0.70

<0.001

Sonography

146

156

0.94

0.90–0.99

0.02

 Ambulatory care

138

147

0.94

0.89–0.99

0.02

 Inpatient care

8

9

0.89

0.72–1.11

0.28

Computed tomography

26

21

1.24

1.09–1.41

0.001

 Ambulatory care

21

18

1.17

1.01–1.35

0.03

 Inpatient care

5

3

1.66

1.19–2.31

0.002

Magnetic resonance imaging

32

14

2.29

1.84–2.87

<0.001

 Ambulatory care

29

10

2.90

2.26–3.77

<0.001

 Inpatient care

3

4

0.74

0.42–1.27

0.25

Radioisotope scanning

10

10

1.00

0.73–1.37

1.00

 Ambulatory care

8

8

1.00

0.70–1.42

1.00

 Inpatient care

2

2

1.00

0.48–2.08

1.00

Positron emission tomography

0.9

0.5

2.00

0.54–9.08

0.27

 Ambulatory care

0.7

0.4

2.00

0.43–12.36

0.34

 Inpatient care

0.2

0.1

2.00

0.10–118

0.63

Interventional procedures

12

17

0.71

0.60–0.83

<0.001

 Ambulatory care

9

14

0.64

0.535–0.78

<0.001

 Inpatient care

3

3

1.00

0.69–1.45

1.00