Table 2.

Attrition

Patient selection criteria	n	%
Patients in MarketScan® Commercial and Medicare Research Databases from January 1, 2011–July 31, 2015a	131,603,746
Female	67,754,615	100.0
Received a screening mammographyb	11,687,689	17.3
Received a breast imaging diagnostic procedure (diagnostic mammography, ultrasound, MBI, tomosynthesis, MRI, or biopsy)c	2,168,710	3.2
Continuous health plan coverage ≥13 months prior to the index dated	1,544,629	2.3
Aged ≥18 years at index	1,275,804	1.9
No inpatient or outpatient claims with a procedure code indicating any diagnostic breast imaging in the pre-index period (except screening mammography)	1,040,601	1.5
No inpatient or outpatient claims with a new breast cancer diagnosis at any time in the pre-index period	1,039,473	1.5
Patients with ≥13 months of continuous eligibility	875,526	1.3

Notes:

^aAll patients with health coverage in the MarketScan database, including patients who did NOT have any breast imaging procedures.

^bScreening mammography was identified using ICD-9-CM procedure codes V76.11, V76.12, V76.19, HCPCS code G0202, or CPT code 77057.

^cPatients receiving breast imaging diagnostic procedures were not required to have had a claim for screening mammography.

^dThe index date is the first medical claim date for any diagnostic mammography, ultrasound, MBI, tomosynthesis, MRI, or biopsy performed.

Abbreviations: CPT, Common Procedural Terminology code; HCPCS, Healthcare Common Procedure Coding System code; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification, procedure code; MBI, molecular breast imaging; MRI, magnetic resonance imaging.