Differences in reproductive risk factors for breast cancer in middle-aged women in Marin County, California and a sociodemographically similar area of Northern California

Table 4 Five-Year (2000–2004) Incidence Rates of Invasive Breast Cancer for Kaiser Permanente Female Members Aged 40–64 in Marin County and East/Central Contra Costa County, California¹

	Marin	East/Central Contra Costa	p-value
Number of cases/Population	184/65,937	384/148,388
Five-year rate per 100,000 women adjusted for age	257.7 (220.9 – 298.8)	240.5 (216.8 – 266.0)	p = .69
Five-year rate per 100,000 women adjusted for age and ethnicity	264.7 (224.6 – 309.8)	245.7 (218.9 – 274.9)	p = .74

¹ Rates adjusted to the age and race/ethnic (White nonHispanic vs. Other) composition of the female population in each geographic area per U.S. Census 2000 estimates.

ISSN: 1472-6874