Specificity
What is specificity?
The Breast Cancer Surveillance Consortium defines specificity as “the proportion of non-cancers during follow-up that had a negative mammography result” (BCSC Standard Definitions, Version 3.1).
What is the difference between sensitivity and specificity?
Sensitivity is the likelihood a patient will receive a positive examination when cancer truly exists. Specificity is the opposite of sensitivity, as it is the likelihood a patient will receive a negative examination when cancer does not exist.
What are the desirable performance benchmarks for specificity?
The performance benchmarks for specificity are as follows:
- Screening mammograms: 88.9%
- Diagnostic mammograms: 90.5%
How is specificity calculated?
Specificity is calculated with the following formula:
TN / (FP + TN)
- TN= True Negatives
- FP= False Positives
Sources:
Breast Cancer Surveillance Consortium (BCSC). (n.d.). BCSC Standard Definitions, Version 3.1. BCSC. https://www.bcsc-research.org/application/files/1516/9505/9808/BCSC_Data_Definitions_v3.1__2023.09.15.pdf
Funaro, K., Ataya, D., & Niell, B. (2021). Understanding the mammography audit. Radiologic Clinics of North America, 59(1), 41–55. https://doi.org/10.1016/j.rcl.2020.09.009
Breast Cancer Surveillance Consortium (BCSC). (n.d.). Screening Mammography Sensitivity, Specificity, & False Negative Rate. BCSC-Research. https://www.bcsc-research.org/statistics/screening-performance-benchmarks/screening-sens-spec-false-negative
Breast Cancer Surveillance Consortium (BCSC). (n.d.). Diagnostic Mammography Sensitivity, Specificity, & False Negative Rate. BCSC-Research. https://www.bcsc-research.org/statistics/diagnostic-performance-benchmarks/diagnostic-mammography-sensitivity-specificity