Digital breast tomosynthesis (DBT) is a recent technological advancement in mammography and is performed by obtaining tomographic images of the breast, which are acquired by low-dose exposures along an arc and are reconstructed into a series of thin images that can be viewed consecutively1. Several studies have shown that DBT increases the cancer detection rate and reduces the recall rate associated with screening mammography, compared to full field digital mammography (FFDM), improving both sensitivity and specificity1–2.
DBT has two main potential disadvantages, one of which is increased radiation. Since DBT is traditionally performed as a combined exam with FFDM, there is an increased radiation dose compared to FFDM alone. To reduce radiation dose, many institutions (including ours) perform DBT with a synthetic 2D mammogram (instead of FFDM), obtained via an algorithm that reconstructs the DBT images. The advantage of performing DBT with a synthetic 2D mammogram is that the radiation dose is similar to that of FFDM alone. The second potential disadvantage of DBT is the cost to patients. Although Medicare and Medicaid cover DBT, it is not universally covered by private insurance; therefore some women may have to pay for it out-of-pocket.
At many institutions (including ours), patients who present for screening mammography are given the choice of DBT or FFDM. The purpose of our study was to evaluate the impact of insurance coverage and other socioeconomic factors on patients’ choice of screening mammography type. We also assessed patients’ main reasons for selecting DBT versus FFDM.
This study was approved by the Institutional Review Board and was performed over a 6-month period (July 11th, 2016 to January 13th, 2017) at the four outpatient clinics at our academic medical institution that offered both DBT and FFDM. All women who presented for screening mammography were given an anonymous paper survey (Figure 1) upon arrival to voluntarily complete during the visit.
Figure 1.
Survey
Patients were informed that they would receive a bill (typically $57), if their insurance company denied payment for DBT. A list of the insurance companies covering DBT was available at each site.
Patients choosing DBT were compared to those choosing FFDM using Fisher’s exact test (insurance coverage) and Cochran-Armitage test for trend (ordinal measures of income and education). Analysis was performed using SAS version 9.3 (SAS Institute, Inc., Cary, North Carolina). All reported p-values are two-sided, and statistical significance was defined as a p-value of less than 0.05.
A total of 1,741 patients completed the survey (15% of all screening mammogram patients during the study period). Among the surveys completed, 32 (1.8%) were unusable because the type of screening mammogram selected was not reported. The remaining 1,709 completed surveys were used for data analysis. DBT was chosen by 1,301 of the patients (76.1%), while the remaining 408 patients (23.9%) chose FFDM (similar to the percentages of the overall screening population at our institution).
Most of the patients who chose DBT (n=694; 60.8%) reported doing so because of fear of missed cancer, while most of the patients who chose FFDM (n=242; 68.6%) reported cost as the reason (Figure 2).
Figure 2.
Patient-reported reasons for choosing Full Field Digital Mammography (FFDM) versus Digital Breast Tomosynthesis (DBT)
Patients who chose DBT were significantly more likely to have insurance coverage than those who chose FFDM (Table 1). Additionally, most (89%) of the patients who selected FFDM and did not have insurance coverage for DBT reported that they would choose DBT if their insurance company begins to cover it. Patients who chose DBT had significantly higher income and higher education levels than those who chose FFDM (Table 1).
Table 1.
Impact of socioeconomic factors on choice of screening mammography type
| Characteristic | DBT N (%) |
FFDM N (%) |
P value* |
|---|---|---|---|
| Insurance coverage for DBT: | n=1289 | n=402 | <0.001 |
| Yes | 783 (60.7) | 35 (8.7) | |
| No | 96 (7.4) | 170 (42.3) | |
| Unsure | 410 (31.8) | 197 (49.0) | |
| Household income: | n=791 | n=293 | <0.001 |
| < $40,000 | 117 (14.8) | 62 (21.2) | |
| $40–80,000 | 227 (28.7) | 101 (34.5) | |
| $80–120,000 | 198 (25.0) | 78 (26.6) | |
| >$120,000 | 249 (31.5) | 52 (17.8) | |
| Education: | n=858 | n=315 | 0.001 |
| Some high school | 20 (2.3) | 14 (4.4) | |
| High school graduate | 229 (26.7) | 99 (31.4) | |
| College degree | 324 (37.8) | 123 (39.0) | |
| Masters degree | 211 (24.6) | 63 (20.0) | |
| Doctoral degree | 74 (8.6) | 16 (5.1) |
P value from Fisher’s exact test for insurance and Cochran-Armitage test for trend for income and education
Our results show that patients who reported having insurance coverage for DBT were significantly more likely to choose DBT. Patients with higher annual household income and those who are more educated were also significantly more likely to choose DBT, possibly because they could more easily afford the potential out-of-pocket costs and understand the benefits of DBT. In the current climate of healthcare policy uncertainty, it is imperative to understand the effect that policy can have on patients’ healthcare decisions. Universal insurance coverage for DBT would improve access for patients.
Acknowledgements
The authors would like to thank the following people for their assistance with data collection and data entry: Jeryl Hammond, Kelly Fuchs, MBA, Cynthia D. Buren, AAS, R.T.(R)(M), Sharlene Bartenfelter, Mary E. Stierhoff, BA, Ashley Carpenter, MA, and Margaret Leathers, MS. We would also like to acknowledge support for the statistical analysis from the Johns Hopkins Institute for Clinical and Translational Research (ICTR), which is funded in part by Grant Number UL1 TR001079 from the National Center for Advancing Translational Sciences (NCATS).
Grant Support: Kathryn A. Carson, ScM, reports funding from the National Center for Advancing Translational Sciences (NCATS), a component of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research.
Footnotes
Conflict of interest:
Susan Harvey, MD, reports working as a consultant for Hologic and IBM Watson Medical
REFERENCES
- 1.Conant EF, Beaber EF, Sprague BL, et al. Breast cancer screening using tomosynthesis in combination with digital mammography compared to digital mammography alone: a cohort study within the PROSPR consortium. Breast Cancer Res Treat. 2016. February;156(1):109–16. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Greenberg JS, Javitt MC, Katzen J, Michael S, Holland AE. Clinical performance metrics of 3D digital breast tomosynthesis compared with 2D digital mammography for breast cancer screening in community practice. AJR Am J Roentgenol. 2014. September;203(3):687–93. [DOI] [PubMed] [Google Scholar]