Optimum screening mammography reading volumes: evidence from the NHS Breast Screening Programme

A comparison of breast screening performance based on a standardised test, during and outside of the COVID-19 lockdown period

PURPOSE

In the UK, the COVID-19 pandemicand the resulting lockdown significantly impacted routine breast screening and led to reduced case volumes for breast screening readers. The aim of the study was to evaluate whether breast screening performance on a test-set based assessment scheme (PERFORMS) varied over time, in association with the lockdown period.

METHOD

In this retrospective study, performance data were obtained for all breast cancer screening readers in England who completed the PERFORMS schemes based on digital mammography (from 2015 to 2022). Cancer detection (sensitivity), correct return to screen (specificity) and the difference between the sensitivity and specificity were calculated for each breast screener in each PERFORMS scheme.

RESULTS

During the study period, 4906 readers participated in eight PERFORMS schemes. Both the cancer detection (H(7) = 775.56, p <.00001) and correct return to screen rate (H(7) = 401.13, p <.00001) varied significantly by scheme. The difference between cancer detection and correct return to screen rate in the scheme administered during the lockdown period was significantly higher than in all other schemes (p <.05, Bonferroni correction applied).

CONCLUSIONS

The performance of breast screeners on the PERFORMS test-set based assessment scheme which was administered during the lockdown period, was characterised by markedly high sensitivity and low specificity when compared to their performance on other tests taken pre-COVID and following the lockdown.

Performance of Radiologists and Radiographers in Double Reading Mammograms: The UK National Health Service Breast Screening Program

Background Double reading can be used in screening mammography, but it is labor intensive. There is limited evidence on whether trained radiographers (ie, technologists) may be used to provide double reading. Purpose To compare the performance of radiologists and radiographers double reading screening mammograms, considering reader experience level. Materials and Methods In this retrospective study, performance and experience data were obtained for radiologists and radiographer readers of all screening mammograms in England from April 2015 to March 2016. Cancer detection rate (CDR), recall rate (RR), and positive predictive value (PPV) of recall based on biopsy-proven findings were calculated for first readers. Performance metrics were analyzed according to reader professional group and years of reading experience using the analysis of variance test. P values less than .05 were considered to indicate statistically significant difference. Results During the study period, 401 readers (224 radiologists and 177 radiographers) double read 1 404 395 screening digital mammograms. There was no difference in CDR between radiologist and radiographer readers (mean, 7.84 vs 7.53 per 1000 examinations, respectively; P = .08) and no difference for readers with more than 10 years of experience compared with 5 years or fewer years of experience, regardless of professional group (mean, 7.75 vs 7.71 per 1000 examinations respectively, P = .87). No difference in the mean RR was observed between radiologists and radiographer readers (5.0% vs 5.2%, respectively, P = .63). A lower RR was seen for readers with more than 10 years of experience compared with 5 years or fewer, regardless of professional group (mean, 4.8% vs 5.8%, respectively; P = .001). No variation in PPV was observed between them (P = .42), with PPV values of 17.1% for radiologists versus 16.1% for radiographers. A higher PPV was seen for readers with more than 10 years of experience compared with 5 years or less, regardless of professional group (mean, 17.5% and 14.9%, respectively; P = .02). Conclusion No difference in performance was observed between radiographers and radiologists reading screening mammograms in a program that used double reading. Published under a CC BY 4.0 license Online supplemental material is available for this article. See also the editorial by Hooley and Durand in this issue.