Table 1.
Characteristics of Breast Cancer Patients
| Sample Characteristics | Breast Cancer Cases | Controls |
|---|---|---|
| N (%) | N (%) | |
| Sample size | 29,110 (100.0) | 87,330 (100.0) |
| Age at diagnosisa, in years | ||
| 67–69 | 4,990 (17.1) | 15,035 (17.2) |
| 70–74 | 7,585 (26.1) | 22,631 (25.9) |
| 75–79 | 7,016 (24.1) | 20,846 (23.9) |
| 80–84 | 5,595 (19.2) | 15,319 (17.5) |
| 85–94 | 3,924 (13.5) | 13,499 (15.5) |
| Race | ||
| White | 25,823 (88.7) | 72,561 (83.1) |
| Black | 2,031 (7.0) | 7,118 (8.2) |
| Other | 1,256 (4.3) | 7,651 (8.8) |
| Elixhauser comorbid score | ||
| No conditions | 12,696 (43.6) | 38,088 (43.6) |
| 1–2 conditions | 11,450 (39.3) | 32,675 (37.4) |
| ≥3 conditions | 4,964 (17.1) | 16,567 (19.0) |
| Metropolitan statistical area | ||
| Yes | 4,690 (16.1) | 14,533 (16.6) |
| No | 24,420 (83.9) | 72,797 (83.4) |
| Median household income | ||
| <$33,000 | 5,863 (20.1) | 17,338 (19.9) |
| $33,000–$39,999 | 4,293 (14.7) | 14,674 (16.8) |
| $40,000–$49,999 | 6,077 (20.9) | 18,841 (21.6) |
| $50,000–$62,999 | 5,750 (19.8) | 16,948 (19.4) |
| ≥$63,000 | 7,122 (24.5) | 16,626 (19.0) |
| Year at diagnosisa | ||
| 2005 | 7,141 (24.5) | 21,423 (24.5) |
| 2006 | 7,236 (24.9) | 21,708 (24.9) |
| 2007 | 7,429 (25.5) | 22,287 (25.5) |
| 2008 | 7,304 (25.1) | 21,912 (25.1) |
| Baseline annual Medicare expenditureb | ||
| Median (interquartile range) ($) | $2,079 ($745–$5,467) | $2,080 ($745–$5,474) |
| Breast cancer stage | ||
| Stage I | 16,117 (55.4) | |
| Stage II | 9,707 (33.3) | |
| Stage III | 3,286 (11.3) | |
| Tumor size | ||
| <2 cm | 17,569 (60.4) | |
| 2–5 cm | 9,635 (33.1) | |
| >5 cm | 1,538 (5.3) | |
| Missing | 368 (1.3) | |
| Laterality | ||
| Left | 14,780 (50.8) | |
| Right | 14,319 (49.2) | |
| Other/unknown | 11 (0.0) | |
| Lymph node involvement | ||
| Yes | 7,119 (24.5) | |
| No/unknown | 21,991 (75.5) | |
| Hormone receptor statusc | ||
| Positive | 23,312 (80.1) | |
| Negative | 4,047 (13.9) | |
| Unknown | 1,751 (6.0) | |
Percentages may not add to 100% due to rounding.
a
Measured at the time of diagnosis (for cancer patients) or index date (for controls).
b
Assessed over a 12‐month period from 18 through 6 months prior to diagnosis/index date to avoid cost associated with work‐up leading to cancer diagnosis.
c
Estrogen or progesterone.