The investigators conducted a controlled pre-post study to measure the occurrence of outcomes both before and after women were switched from a low-deductible health plan, defined as a maximum annual deductible of $500 or less, to a high-deductible plan, defined as an annual deductible of $1,000 or more.
The study population comprised 273,499 women aged 25-64 years who had no evidence of breast cancer before they were included in the study. The women had all been enrolled in a low-deductible plan for at least 1 year, and were then switched by employer mandate to a high-deductible plan and followed for up to 4 additional years.
Controls included 2.4 million women matched by time of inclusion whose employers continued to offer only low-deductible health plans.
Although at baseline there were no differences between the study sample and the controls in time to first diagnostic breast imaging, breast biopsy, diagnosis of early stage breast cancer, or initiation of breast cancer chemotherapy, at follow-up the women who had been switched to the high-deductible plans had significant delays in all categories.