Mammography Volume Research Articles

The Importance of Outcomes Ascertainment for Accurate Assessment of the Mammography Screening Cancer Detection Rate: A Simulation Study

PurposeCancer detection rate (CDR), an important metric in the mammography screening audit, is designed to ensure adequate sensitivity. Most practices use biopsy results as the reference standard; however, commonly ascertainment of biopsy results is incomplete. We used simulation to determine the relationship between the cancer ascertainment rate of biopsy (AR-biopsy), CDR estimation, and associated error rates in classifying whether practices and radiologists meet the established ACR benchmark of 2.5 per 1,000. Materials and MethodsWe simulated screening mammography volume, number of cancers detected, and CDR, using negative binomial and beta-binomial distributions, respectively. Simulations were performed at both the practice and radiologist level. Average CDR was based on linearly rescaling a published CDR by the AR-biopsy. CDR distributions were simulated for AR-biopsy between 5% and 100% in steps of five percentage points and were summarized with boxplots and smoothed histograms over the range of AR-biopsy, to quantify the proportion of practices and radiologists meeting the ACR benchmark at each level of AR-biopsy. ResultsDecreasing AR-biopsy led to an increasing probability of categorizing CDR performance as being below the ACR benchmark. Our simulation predicts that at the practice level, an AR-biopsy of 65% categorizes 17.6% below the benchmark (compared to 1.6% at an AR-biopsy of 100%), and at the radiologist level, an AR-biopsy of 65% categorizes 34.7% as being below the benchmark (compared to 11.6% at an AR-biopsy of 100%). ConclusionsOur simulation demonstrates that decreasing the AR-biopsy (in currently clinically relevant ranges) has the potential to artifactually lower the assessed CDR on both the practice and radiologist levels and may, in turn, increase the chance of erroneous categorization of underperformance per the ACR benchmark.

Experience of a single healthcare system with screening mammography before and after COVID-19 shutdown

PurposeTo evaluate COVID-19's longitudinal impact on screening mammography volume trends. MethodsHIPAA-compliant, IRB-approved, single institution, retrospective study of screening mammogram volumes before (10/21/2016–3/16/2020) and greater than two years after (6/17/2020-11/30/2022) a state-mandated COVID-19 shutdown (3/17/2020–6/16/2020) were reviewed. A segmented quasi-poisson linear regression model adjusting for seasonality and network and regional population growth compared volume trends before and after the shutdown of each variable: age, race, language, financial source, risk factor for severe COVID-19, and examination location. ResultsAdjusted model demonstrated an overall increase of 65 screening mammograms per month before versus a persistent decrease of 5 mammograms per month for >2 years after the shutdown (p < 0.0001). In subgroup analysis, downward volume trends were noted in all age groups <70 years (age < 50: +9/month before vs. −7/month after shutdown; age 50–60: +17 vs. −7; and age 60–70: +21 vs. −2; all p < 0.001), those identifying as White (+55 vs. −8, p < 0.0001) and Black (+4 vs. +1, p = 0.009), all financial sources (Medicare: +22 vs. −3, p < 0.0001; Medicaid: +5 vs. +2, p = 0.006; private insurance/self-pay: +38 vs. −4, p < 0.0001), women with at least one risk factor for severe COVID-19 (+30 vs. −48, p < 0.0001), and screening mammograms performed at a hospital-based location (+48 vs. −14, p = 0.0001). ConclusionThe screening mammogram volume trend more than two years after the COVID-19 shutdown has continued to decline for most patient populations. Findings highlight the need to identify additional areas for education and outreach.

Breast exam use during the protracted COVID-19 pandemic, by age, race, and geography.

In this study we analyzed data collected from the onset of the COVID-19 pandemic through March 31, 2022 to identify temporal shifts in breast exam volume. Screening mammography volume stabilized toward the end of the study period, while diagnostic exam volume varied over time and by age. Older women experienced a decline in diagnostic exam volume between August 2020 and April 2021 that was not observed among women aged 50 years or less (50-69 years, monthly percentage change (MPC): -6.5; and 70+ years, MPC: -15.7). With respect to breast biopsy volume, women younger than 70 years of age had increased exam volume beginning in April 2020 and June 2020, whereas a corresponding increase among older women was delayed until April 2021(70+ years, MPC: 9.3). Findings from our study suggest a temporal shift in the use of breast exams that could result in differential detection of breast cancer by age.

Changes in Mammography Use by Women's Characteristics During the First 5 Months of the COVID-19 Pandemic.

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic led to a near-total cessation of mammography services in the United States in mid-March 2020. It is unclear if screening and diagnostic mammography volumes have recovered to pre-pandemic levels and whether utilization has varied by women’s characteristics.MethodsWe collected data on 461,083 screening mammograms and 112,207 diagnostic mammograms conducted during January 2019 through July 2020 at 62 radiology facilities in the Breast Cancer Surveillance Consortium. We compared monthly screening and diagnostic mammography volumes before and during the pandemic, stratified by age, race/ethnicity, breast density, and family history of breast cancer.ResultsScreening and diagnostic mammography volumes in April 2020 were 1.1% (95% confidence interval [CI] = 0.5% to 2.4%) and 21.4% (95% CI = 18.7% to 24.4%) of April 2019 pre-pandemic volumes, respectively, but by July 2020 rebounded to 89.7% (95% CI = 79.6% to 101.1%) and 101.6% (95% CI = 93.8% to 110.1%) of July 2019 pre-pandemic volumes, respectively. The year-to-date cumulative volume of screening and diagnostic mammograms performed through July 2020 was 66.2% (95% CI = 60.3% to 72.6%) and 79.9% (95% CI = 75.4% to 84.6%), respectively, of year-to-date volume through July 2019. Screening mammography rebound was similar across age groups and by family history of breast cancer. Monthly screening mammography volume in July 2020 for Black, White, Hispanic, and Asian women reached 96.7% (95% CI = 88.1% to 106.1%), 92.9% (95% CI = 82.9% to 104.0%), 72.7% (95% CI = 56.5% to 93.6%), and 51.3% (95% CI = 39.7% to 66.2%) of July 2019 pre-pandemic volume, respectively.ConclusionDespite a strong overall rebound in mammography volume by July 2020, the rebound lagged among Asian and Hispanic women and a substantial cumulative deficit in missed mammograms accumulated, which may have important health consequences.

Influence of Mammography Volume on Radiologists' Performance: Results from BreastScreen Norway.

Background Several European screening mammography programs that use independent double reading with consensus recommend an annual minimum reading volume of 5000 mammograms per radiologist. This recommendation is based only on expert opinion, and the influence of reading volume on performance in such programs is unknown. Purpose To examine the influence of annual and cumulative reading volume on radiologists' reading performance for digital mammography in a screening program that uses independent double reading with consensus. Materials and Methods This retrospective study included data from digital mammographic examinations in BreastScreen Norway obtained from 2006 to 2016. Multilevel mixed-effects models were used to determine how sensitivity, rate of screening-detected breast cancer (SDC), and false-positive rate (FPR) before and after consensus meeting related to annual and cumulative reading volume. Results The study included 2 373 433 readings performed by 121 radiologists. The median annual reading volume ranged from 153 to 19 500 mammograms, and the median cumulative reading volume was 30 566 mammograms. Sensitivity and SDC rate were relatively stable at 87% to 90% and 4.9 to 4.7 per 1000 readings (0.49% and 0.47%), respectively, between 100 and 10 000 annual readings and at 88% to 89% and 4.8 to 4.9 per 1000 readings (0.48% and 0.49%) between 500 and 100 000 cumulative readings. There was a decreasing trend with higher annual volumes (P for trend < .001 for both) to a sensitivity of 81% and SDC rate of 3.9 per 1000 readings (0.39%) at 18 000 readings. There was a decreasing trend in FPR before and after consensus with higher annual and cumulative volumes (P for trend < .001 for all). FPRs before consensus meeting were 5.3% at 100 annual readings and 4.0% at 4000 annual readings and were 6.7% at 500 cumulative readings and 3.6% at 20 000 cumulative readings. FPRs after consensus meeting were 2.5% at 100 annual readings and 2.3% at 4000 annual readings and were 2.7% at 500 cumulative readings and 2.2% at 20 000 cumulative readings. Conclusion Annual reading volumes between 4000 and 10 000 mammograms and cumulative reading volumes greater than 20 000 mammograms may be the most optimal volumes for achieving high reading performance in a screening program with independent double reading. © RSNA, 2019 See also the editorial by Rosenberg and Seidenwurm in this issue.

Facility Mammography Volume in Relation to Breast Cancer Screening Outcomes.

To clarify the relationship between facility-level mammography interpretive volume and breast cancer screening outcomes. We calculated annual mammography interpretive volumes from 2000-2009 for 116 facilities participating in the U.S. Breast Cancer Surveillance Consortium (BCSC). Radiology, pathology, cancer registry, and women's self-report information were used to determine the indication for each exam, cancer characteristics, and patient characteristics. We examined the effect of annual total volume and percentage of mammograms that were screening on cancer detection rates using multinomial logistic regression adjusting for age, race/ethnicity, time since last mammogram, and BCSC registries. "Good prognosis" tumours were defined as screen-detected invasive cancers that were <15 mm, early stage, and lymph node negative at diagnosis. From 3,098,481 screening mammograms, 9,899 cancers were screen-detected within one year of the exam. Approximately 80% of facilities had annual total interpretive volumes of >2,000 mammograms, and 42% had >5,000. Higher total volume facilities were significantly more likely to diagnose invasive tumours with good prognoses (odds ratio [OR] 1.32; 95% confidence interval [CI] 1.10-1.60, for total volume of 5,000-10,000/year v. 1,000-2,000/year; p-for-trend <0.001). A concomitant decrease in tumours with poor prognosis was seen (OR 0.78; 95%CI 0.63-0.98 for total volume of 5,000-10,000/year v. 1,000-2,000/year). Mammography facilities with higher total interpretive volumes detected more good prognosis invasive tumours and fewer poor prognosis invasive tumours, suggesting that women attending these facilities may be more likely to benefit from screening.

Process improvement in breast cancer care: Is mammography volume associated with a greater need for process improvement?

45 Background: Chicago black women are 62% more likely to die from breast cancer than white women. Previous data from 39 Chicago hospitals suggested significant variation in mammography quality (Chicago Breast Cancer Quality Consortium, 2010). We developed process improvement recommendations for sites that participated in our care process assessment (Weldon CB, et al, ASCO-Abstract-6120-2012). This study was funded through a generous grant from the Susan G. Komen for the Cure Foundation. We compared improvement needs between high and low patient volume institutions. Methods: Using Deming’s PDCA cycle for continuous improvement, we created care process improvement recommendations for 25 Chicago institutions with the patient base averaging more than 50% minority patients (20 community, 3 academic and 2 public hospitals). Low mammography volume (&lt; 5,000 mammograms/ year) was reported by 12 of the 25 sites. Recommendations are based on analysis across sites, literature, and input from institution staff. Thematic and statistical analyses were performed using simple frequencies and Fisher's exact test. Results: Improvement recommendations are classified into nine areas (see Table). We found that 100% (12/12) of low mammography volume institutions have specific improvement needs in 6 or more process improvement areas, as compared to 23% (3/13) of the high mammography volume institutions (p value &gt; 0.0001). Conclusions: Lower volume mammography sites have a larger need for breast cancer care process improvements. [Table: see text]

Process improvement in breast cancer care: Is mammography volume associated with a greater need for process improvement?

6609 Background: Chicago Black women are 62% more likely to die from breast cancer than White women. Previous data from 39 Chicago hospitals suggested significant variation in mammography quality (Chicago Breast Cancer Quality Consortium, 2010). We developed process improvement recommendations for sites that participated in our care process assessment (Weldon CB, et al, ASCO-Abstract-6120-2012). This study was funded through a generous grant from the Susan G. Komen for the Cure Foundation. We compared improvement needs between high and low patient volume institutions. Methods: Using Deming’s PDCA cycle for continuous improvement, we created care process improvement recommendations for 25 Chicago institutions with the patient base averaging more than 50% minority patients (20 community, 3 academic and 2 public hospitals). Low mammography volume (&lt; 5000 mammograms/ year) was reported by 12 of the 25 sites. Recommendations are based on analysis across sites, literature, and input from institution staff. Thematic and statistical analyses were performed using simple frequencies and Fisher's exact test. Results: Improvement recommendations are classified into nine areas, see table. We found that 100% (12/12) of low mammography volume institutions have specific improvement needs in 6 or more process improvement areas, as compared to 23% (3/13) of the high mammography volume institutions (pvalue &gt; 0.0001). Conclusions: Lower volume mammography sites have a larger need for breast cancer care process improvements. [Table: see text]

Is Confidence of Mammographic Assessment a Good Predictor of Accuracy?

Interpretive accuracy varies among radiologists, especially in mammography. This study examines the relationship between radiologists' confidence in their assessments and their accuracy in interpreting mammograms. In this study, 119 community radiologists interpreted 109 expert-defined screening mammography examinations in test sets and rated their confidence in their assessment for each case. They also provided a global assessment of their ability to interpret mammograms. Positive predictive value (PPV) and negative predictive value (NPV) were modeled as functions of self-rated confidence on each examination using log-linear regression estimated with generalized estimating equations. Reference measures were cancer status and expert-defined need for recall. Effect modification by weekly mammography volume was examined. Radiologists who self-reported higher global interpretive ability tended to interpret more mammograms per week (p = 0.08), were more likely to specialize (p = 0.02) and to have completed a fellowship in breast or women's imaging (p = 0.05), and had a higher PPV for cancer detection (p = 0.01). Examinations for which low-volume radiologists were "very confident" had a PPV of 2.93 times (95% CI, 2.01-4.27) higher than examinations they rated with neutral confidence. Trends of increasing NPVs with increasing confidence were significant for low-volume radiologists relative to noncancers (p = 0.01) and expert nonrecalls (p < 0.001). A trend of significantly increasing NPVs existed for high-volume radiologists relative to expert nonrecall (p = 0.02) but not relative to noncancer status (p = 0.32). Confidence in mammography assessments was associated with better accuracy, especially for low-volume readers. Asking for a second opinion when confidence in an assessment is low may increase accuracy.

Abstract A101: Quality improvement as a tool to reduce health outcomes disparities in breast cancer: The Chicago Breast Cancer Quality Consortium as a model

Abstract Despite African American (AA) women in the US and Chicago having a lower incidence of breast cancer compared to White women, AA women are more likely to die of the disease. The situation is especially concerning in Chicago where the disparity is one of the highest in the country with AA women being 62% more likely to die of breast cancer compared to White women. Both national and Chicago-specific data suggests that differential quality of breast health care between the two groups plays a role in the disparity. Against this backdrop, the Chicago Breast Cancer Quality Consortium was established in 2008 to bring area providers together to share breast cancer quality screening and treatment data with the aim of analyzing whether disparities in quality were contributing to disparities in outcomes and to improve quality where quality deficits were identified. Expert advisory boards established for mammography and treatment developed consensus on collection methods and quality measures. Highest priority was given to measures of clinical outcomes that could be feasibly estimated through collection of aggregate data from all participating facilities, including those with the lowest resources who disproportionately serve minority women. Standardized forms were developed to record specific counts, and then entered onto a secure web-based portal. Measures for screening included cancer detection rate, proportion of cancers found that were minimal, proportion of cancers found that were early stage, timeliness of follow up after an abnormal mammogram and recall rate. Measures for treatment included proportion of patients receiving radiation after breast conserving surgery, proportion of patients tested for ER and PR, proportion of patients tested for HER-2, proportion of Her-2 positive patients who were treated with trastuzumab, and timeliness of treatment after diagnosis. Data on screening (39 facilities) and/or treatment quality metrics (21 facilities) was submitted by 43 of the 67 Metropolitan Chicago hospitals with mammography volume above 480 per year. Information regarding patient demographics including payor mix and race/ethnicity for both inpatient and outpatient services at each participating facility was derived from data reported annually to the Illinois Department of Public Health (IDPH) hospital profiles. Results from this first year of data collection will be presented and include the following results: Only 3 of the 10 benchmarks were shown to be met by half or more of the facilities examined. None of the 10 benchmarks were shown to be met by two-thirds or more of the facilities examined. The benchmark for recall rate was shown to be met by the largest percentage of facilities (62%), followed by cancer detection rate (39%) and lost to follow-up at diagnostic imaging (54%). Almost one third (28%) of facilities were able to show that they met the benchmarks for proportion minimal breast cancers, and about one fourth (26%) were able to show that they met standards for proportion early stage breast cancers. From these data it is clear that facilities are having difficulty meeting the benchmark values, and gathering and tracking the data necessary to be able create reliable estimates that could form the basis of quality improvement initiatives. Several of these measures are essential for a facility to be able to review its mammography quality (both image quality and reading effectiveness) and timeliness of follow up. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):A101.

How Widely Is Computer-Aided Detection Used in Screening and Diagnostic Mammography?

The aim of this study was to determine how widely computer-aided detection (CAD) is used in screening and diagnostic mammography and to see if there are differences between hospital facilities and private offices. The nationwide Medicare Part B fee-for-service databases for 2004 to 2008 were used. The Current Procedural Terminology(®) codes for screening and diagnostic mammography (both digital and screen film) and the CAD add-on codes were selected. Procedure volume was compared for screening vs diagnostic mammography and for hospital facilities vs private offices. From 2004 to 2008, Medicare screening mammography volume increased slightly from 5,728,419 to 5,827,326 (+2%), but the use of screening CAD increased from 2,257,434 to 4,305,595 (+91%). By 2008, CAD was used in 74% of all screening mammographic studies. During this same time period, the Medicare volume of diagnostic mammography declined slightly from 1,835,700 to 1,682,026 (-8%), but the use of diagnostic CAD increased from 360,483 to 845,461 (+135%). By 2008, CAD was used in 50% of all diagnostic mammographic studies. In hospital facilities in 2008, CAD was used in 70% of all screening mammographic studies, compared with 81% in private offices. For diagnostic mammography in 2008, CAD was used in 48% in hospitals, compared with 55% in private offices. Despite some operational drawbacks to using CAD, radiologists have embraced it in an effort to improve cancer detection. Its use has grown rapidly, and in 2008, it was used in three-quarters of all screening mammographic studies and half of all diagnostic mammographic studies. Women undergoing either screening or diagnostic mammography are more likely to receive CAD if they go to a private office than if they go to a hospital facility, although the differences are not great.

Improving Access to Breast Health Services with an Interdisciplinary Model of Care

This article reports a hospital's experience confronting a community crisis, stemming from local and national breast health access issues, and evaluates the subsequent effectiveness of the initiative to improve breast care service. An interdisciplinary Breast Care Facility was developed adjacent to a Community Hospital. Patients receiving breast cancer screening during the year prior to the Breast Center opening (2002) were compared with patients in subsequent years (2003-2005). Program effectiveness was evaluated by examining screening mammography volume, wait times and cancer detection rates. Screening volume increased by 29.6%. Wait times declined from 30 weeks to 3.5 weeks. Initially, patients with a suspicious screening mammography had a 2-3 week delay for diagnostic mammography and the subsequent evaluation took another 3-4 weeks. Both times improved to an average of 2-5 days. Screening cancer detection rates increased from 3.2 per 1,000, to 6.3 per 1,000. In addition, the number of cancers identified by screening increased from 40% to 58%, p = 0.002. Patient satisfaction measured by survey was over 95%, in areas of courtesy, counseling, and overall care. Our study demonstrates that a comprehensive breast center model can increase access to breast care services, improve patient satisfaction and address focal areas of shortage. Furthermore, in the years after the opening of the breast center the cancer detection rate during screening increased, an important observation that needs to be investigated with future studies.

Accuracy of Screening Mammography Interpretation by Characteristics of Radiologists

Radiologists differ in their ability to interpret screening mammograms accurately. We investigated the relationship of radiologist characteristics to actual performance from 1996 to 2001. Screening mammograms (n = 469,512) interpreted by 124 radiologists were linked to cancer outcome data. The radiologists completed a survey that included questions on demographics, malpractice concerns, years of experience interpreting mammograms, and the number of mammograms read annually. We used receiver operating characteristics (ROC) analysis to analyze variables associated with sensitivity, specificity, and the combination of the two, adjusting for patient variables that affect performance. All P values are two-sided. Within 1 year of the mammogram, 2402 breast cancers were identified. Relative to low annual interpretive volume (< or =1000 mammograms), greater interpretive volume was associated with higher sensitivity (P = .001; odds ratio [OR] for moderate volume [1001-2000] = 1.68, 95% CI = 1.18 to 2.39; OR for high volume [>2000] = 1.89, 95% CI = 1.36 to 2.63). Specificity decreased with volume (OR for 1001-2000 = 0.65, 95% CI = 0.52 to 0.83; OR for more than 2000 = 0.76, 95% CI = 0.60 to 0.96), compared with 1000 or less (P = .002). Greater number of years of experience interpreting mammograms was associated with lower sensitivity (P = .001), but higher specificity (P = .003). ROC analysis using the ordinal BI-RADS interpretation showed an association between accuracy and both previous mammographic history (P = .012) and breast density (P<.001). No association was observed between accuracy and years interpreting mammograms (P = .34) or mammography volume (P = .94), after adjusting for variables that affect the threshold for calling a mammogram positive. We found no evidence that greater volume or experience at interpreting mammograms is associated with better performance. However, they may affect sensitivity and specificity, possibly by determining the threshold for calling a mammogram positive. Increasing volume requirements is unlikely to improve overall mammography performance.