Table 1

Study Sample Patient Characteristics, N = 77,306

Predictor Variable

% of All Patients

Demographic

Age, mean (SD)

76 (7)

White race

94

Stage

Stage I

51

Stage II

26

Stage III

10

Stage IV

4

Stages I-III but T or N unknown

9

Extent of disease^a

Axillary LN involvement

19

Metastatic disease

14

Cancer treatment^a

No. visits to surgeon, mean (SD)

4 (3)

No. visits to medical oncologist, mean (SD)

4 (9)

No. visits to radiation oncologist, mean (SD)

3 (5)

Imaging (CT, MRI, PET, or bone scan)

25

Radiation therapy

44

Breast conserving surgery

45

Mastectomy

49

Axillary LN dissection

72

Chemotherapy (any agent)

18

Doxorubicin

7

Paclitaxel

3

No. physician visits, mean (SD)

14 (12)

Screening mammography

78

Influenza vaccine

34

General health status^a

No. hospital admission for any cause, mean (SD)

1 (1)

Charlson comorbidity score

0 comorbid conditions

69

1 comorbid condition

18

2 or more comorbid conditions

8

Unknown

5

Abbreviations: CT computed tomography; LN lymph nodes; MRI magnetic resonance imaging PET positron emission tomography; SD standard deviation

^a As indicated by Medicare claims codes; thus percentage of patients with code for metastatic disease not equal to patients with Stage IV disease.

Smith et al. Epidemiologic Perspectives & Innovations 2010 7:1   doi:10.1186/1742-5573-7-1