Was the drop in mammography rates in 2005 associated with the drop in hormone therapy use?

Abstract

Background: In 2005, mammography rates in the United States dropped nationally for the first time among age-eligible women. An increased risk of breast cancer related to hormone therapy (HT) use reported in 2002 led to a dramatic drop in its use by 2005. Because current users of HT also tend to have higher mammography rates, the authors examined whether concurrent drops in HT and mammography use were associated.

Methods: Multivariate logistic regression was used to test for an interaction between HT use and survey year, controlling for a range of measurable factors in data from the 2000 and 2005 National Health Interview Surveys (NHIS).

Results: Women ages 50 to 64 years were more likely to report a recent mammogram if they also reported more education, a usual source of care, private health insurance, any race except non-Hispanic Asian, talking with an obstetrician/gynecologist or other physician in the past 12 months, or were currently taking HT. Women aged ≥ 65 years were more likely to report a recent mammogram if they also reported younger age (ages 65-74 years), more education, a usual source of care, having Medicare Part B or other supplemental Medicare insurance, excellent health, any race except non-Hispanic Asian, talking with an obstetrician/gynecologist or other physician in the past 12 months, or were currently taking HT.

Conclusions: The change in HT use was associated with the drop in mammography use for women ages 50 to 64 years but not for women aged ≥ 65 years. NHIS data explained 70% to 80% of the change in mammography use.

Figure 1

Population Mammography Screening

Figure 2

What would happen to mammography use in the 24% of the pop who stopped taking HT? Hypothetical 1 - Overall screening level in the population would remain unchanged. This situation represents a SIGNIFICANT INTERACTION between HT use and time because the relationship between HT use and mammography is different after the change in HT use. Hypothetical 2 - Overall screening level in the population would decrease reflecting the larger portion of women in the HT non-user category. This situation results in NO SIGNIFICANT INTERACTION between HT use and time because the relationship between HT use and mammography remains the same after the change in HT use.

Figure 3

Decline in recent screening between 2000 and 2005