At a cost-effectiveness threshold of $100,000 per QALY gained, biennial mammography was cost-effective for women aged 40 to 49 years whose breast density was Breast Imaging Reporting and Data System (BI-RADS) category three or four, or who had previously undergone a breast biopsy and had a family history of breast cancer.
It was cost-effective for women aged 50 to 59 years who had category two, three, or four breast density, or who had category one breast density, had undergone a previous breast biopsy, and had a family history of breast cancer. For all other women in this age range, with category one breast density, mammography every three to four years was cost-effective.
Biennial mammography was cost-effective for all women aged 60 to 69 years, except those with category one breast density and no additional risk factors, for whom mammography every three to four years was cost-effective.
Biennial mammography was cost-effective for women aged 70 to 79 years, with category three or four breast density, and those with either a previous breast biopsy or a family history of breast cancer. For those with category one or two breast density and no additional risk factors, mammography every three to four years was cost-effective.
The cost per QALY with annual compared with biennial screening was greater than $340,000 for all ages and categories of breast density. Annual mammography was never cost-effective.
At a threshold of $50,000 per QALY, biennial mammography was cost-effective for women aged 40 to 49 years, with category three or four breast density and either a previous breast biopsy or a family history of breast cancer.
These results were sensitive to variations in the disutility for a false-positive mammography result and the accuracy of screening. The likelihood of mammography every three or four years being cost-effective was generally low, and biennial mammography had the highest chance of being cost-effective for most patients.