Context Mammography is recommended and is cost-effective for women aged 50 to
69 years, but the value of continuing screening mammography after age 69 years
is not known. In particular, older women with low bone mineral density (BMD)
have a lower risk of breast cancer and may benefit less from continued screening.
Objective To compare life expectancy and cost-effectiveness of screening mammography
in elderly women based on 3 screening strategies.
Design Decision analysis and cost-effectiveness analysis using a Markov model.
Patients General population of women aged 65 years or older.
Interventions The analysis compared 3 strategies: (1) Undergoing biennial mammography
from age 65 to 69 years; (2) undergoing biennial mammography from age 65 to
69 years, measurement of distal radial BMD at age 65 years, discontinuing
screening at age 69 years in women in the lowest BMD quartile for age, and
continuing biennial mammography to age 79 years in those in the top 3 quartiles
of distal radius BMD; and (3) undergoing biennial mammography from age 65
to 79 years.
Main Outcome Measures Deaths due to breast cancer averted, life expectancy, and incremental
Results Compared with discontinuing mammography screening at age 69 years, measuring
BMD at age 65 years in 10,000 women and continuing mammography to age 79 years
only in women with BMD in the top 3 quartiles would prevent 9.4 deaths and
add, on average, 2.1 days to life expectancy at an incremental cost of $66,773
per year of life saved. Continuing mammography to age 79 years in all 10,000
elderly women would prevent 1.4 additional breast cancer deaths and add only
7.2 hours to life expectancy at an incremental cost of $117,689 per year of
life saved compared with only continuing mammography to age 79 years in women
with BMD in the top 3 quartiles.
Conclusions This analysis suggests that continuing mammography screening after age
69 years results in a small gain in life expectancy and is moderately cost-effective
in those with high BMD and more costly in those with low BMD. Women's preferences
for a small gain in life expectancy and the potential harms of screening mammography
should play an important role when elderly women are deciding about screening.