Table 3.
County-Level Analysis of Stage-Specific Incidence Among Women with a New Breast Cancer Diagnosis
| Stage (n = 611 counties) | Connecticut pre- vs. post-IRR (95 % CI) | Other counties pre- vs. post-IRR (95 % CI) | Difference-in-differences IRR (95 % CI) | p value |
|---|---|---|---|---|
| Ages 40–74* | ||||
| DCIS | 0.98 (0.91–1.04) | 1.01 (0.99–1.03) | 0.96 (0.90–1.03) | 0.26 |
| Localized | 1.06 (1.02–1.11) | 1.04 (1.03–1.05) | 1.02 (0.98–1.07) | 0.31 |
| Regional | 0.92 (0.86–0.98) | 0.94 (0.93–0.95) | 0.98 (0.92–1.04) | 0.48 |
| Metastatic | 1.10 (0.97–1.25) | 1.11 (1.09–1.15) | 0.98 (0.86–1.12) | 0.81 |
| Ages 40–49** | ||||
| DCIS | 1.01 (0.91–1.12) | 1.00 (0.97–1.03) | 1.01 (0.91–1.12) | 0.89 |
| Localized | 1.06 (0.98–1.15) | 0.99 (0.97–1.01) | 1.07 (0.99–1.16) | 0.07 |
| Regional | 0.94 (0.84–1.04) | 0.93 (0.91–0.96) | 1.00 (0.90–1.12) | 0.97 |
| Metastatic | 1.07 (0.81–1.41) | 1.12 (1.05–1.19) | 0.96 (0.72–1.27) | 0.77 |
| Ages 50–74** | ||||
| DCIS | 0.94 (0.87–1.00) | 0.99 (0.97–1.01) | 0.95 (0.88–1.02) | 0.13 |
| Localized | 1.04 (0.99–1.08) | 1.02 (1.01–1.04) | 1.01 (–0.97–1.06) | 0.59 |
| Regional | 0.90 (0.84–0.97) | 0.92 (0.91–0.94) | 0.97 (0.91–1.05) | 0.47 |
| Metastatic | 1.08 (0.94–1.25) | 1.09 (1.06–1.13) | 0.99 (0.86–1.14) | 0.90 |
*Models adjusted for median household income, percentage white, percentage insured, physicians per capita, percentage of women ages 40–65, and period during 2013 when data from California were excluded
**Age-stratified models are adjusted for same set of covariates as main model except for age distribution
IRR = incidence rate ratio