Common contributing factors of diagnostic error: A retrospective analysis of 109 serious adverse event reports from Dutch hospitals.

INTRODUCTION: Although diagnostic errors have gained renewed focus within the patient safety domain, measuring them remains a challenge. They are often measured using methods that lack information on decision-making processes given by involved physicians (eg, record reviews). The current study analyses serious adverse event (SAE) reports from Dutch hospitals to identify common contributing factors of diagnostic errors in hospital medicine. These reports are the results of thorough investigations by highly trained, independent hospital committees into the causes of SAEs. The reports include information from involved healthcare professionals and patients or family obtained through interviews. METHODS: All 71 Dutch hospitals were invited to participate in this study. Participating hospitals were asked to send four diagnostic SAE reports of their hospital. Researchers applied the Safer Dx Instrument, a Generic Analysis Framework, the Diagnostic Error Evaluation and Research (DEER) taxonomy and the Eindhoven Classification Model (ECM) to analyse reports. RESULTS: Thirty-one hospitals submitted 109 eligible reports. Diagnostic errors most often occurred in the diagnostic testing, assessment and follow-up phases according to the DEER taxonomy. The ECM showed human errors as the most common contributing factor, especially relating to communication of results, task planning and execution, and knowledge. Combining the most common DEER subcategories and the most common ECM classes showed that clinical reasoning errors resulted from failures in knowledge, and task planning and execution. Follow-up errors and errors with communication of test results resulted from failures in coordination and monitoring, often accompanied by usability issues in electronic health record design and missing protocols. DISCUSSION: Diagnostic errors occurred in every hospital type, in different specialties and with different care teams. While clinical reasoning errors remain a common problem, often caused by knowledge and skill gaps, other frequent errors in communication of test results and follow-up require different improvement measures (eg, improving technological systems).

Utility of Supplemental Training to Improve Radiologist Performance in Breast Cancer Screening: A Literature Review.

PURPOSE: The authors evaluate whether supplemental training for radiologists improves their breast screening performance and how this is measured. METHODS: A systematic search was conducted in PubMed on August 3, 2017. Articles were included if they described supplemental training for radiologists reading mammograms to improve their breast screening performance and at least one outcome measure was reported. Study quality was assessed using the Medical Education Research Study Quality Instrument. RESULTS: Of 2,199 identified articles, 18 were included, of which 17 showed improvement on at least one of the outcome measures, for at least one training activity or subgroup. Two measurement approaches were found. For the first approach, measuring performance on test sets, sensitivity, and specificity were the most reported outcomes (8 of 11 studies). Recall rate is the most reported outcome (6 of 7 studies) for the second approach, which measures performance in actual screening practice. The studies were mainly of moderate quality (Medical Education Research Study Quality Instrument score 11.7 ± 1.7), caused by small sample sizes and the lack of a control group. CONCLUSIONS: Supplemental training helps radiologists improve their screening performance, despite the mainly moderate quality of the studies. There is a need for better designed studies. Future studies should focus on performance in actual screening practice and should look for methods to isolate the training effect. If test sets are used, focus should be on knowledge about correlation between performance on test sets and actual screening practice.

Breast cancer screening effectiveness in Portugal central Region.

The central region of Portugal is covered by an organized population-based breast cancer screening programme. We designed a case-referent study to investigate the association of overall mortality with mammographic screening attendance. The study population (SP) included women aged 50-69 years who received at least one invitation to the breast cancer screening programme. A case was defined as a woman from the SP diagnosed with breast cancer between 2000 and 2006 who died before 1 August 2015. Index invitation (IV) was defined as the most recent invitation before diagnosis of the case. For each case, two referents were sampled from the SP. Referents were women who did not have a breast cancer diagnosis at the IV of the case and alive at time of death of the case. Exposure to screening was defined as participation in the screening examination following the IV and/or participation in the screening round preceding the IV. To correct for self-selection bias, we used a summary correction factor on the basis of published ones. We used conditional logistic regression to estimate the odds ratio (OR) and 95% confidence interval (CI). A total of 227 cases and 454 referents were considered. The overall OR showed a mortality reduction of 47% (OR=0.53, 95% CI: 0.37-0.78). The estimated correction factor was 1.15 (95% CI: 1.06-1.25). This factor was used to correct the crude OR, resulting in a mortality reduction of 33% (OR=0.67, 95% CI: 0.45-1.00). Our results are in agreement with other case-referent studies worldwide, supporting the contribution of screening practices towards the decreasing breast cancer mortality in Portugal.

Mammography in females with an implanted medical device: impact on image quality, pain and anxiety.

OBJECTIVE: To assess the image quality of mammograms in females with an implanted medical device (IMD), to evaluate pain and anxiety during mammography in these females and to investigate the experience of radiographers. METHODS: Image quality was evaluated by two radiographers and one radiologist in the images of females with an IMD participating in the Dutch screening programme (clients). Pain and anxiety were scored using a Numeric Rating Scale in both clients visiting a screening organization and patients from the Isala Hospital, Zwolle. Experience of screening radiographers was collected with a questionnaire. RESULTS: Images of the breast with IMD showed reduced contrast in craniocaudal (CC) and mediolateral-oblique (MLO) views [by both the radiographers and radiologist (range: 11-29%)], less projected breast tissue [only radiographers; CC lateral side: 25.5%, 95% confidence interval (CI): 18.7-32.2] and reduced projection of the pectoral muscle (only radiographers; MLO width pectoral muscle: 31.5%, 95% CI: 24.4-38.7). Clients experienced more pain and anxiety during mammography in the breast with IMD compared to the breast without IMD in the breast (pain difference CC: 0.48 ± 0.16, p = 0.003; pain difference MLO: 0.46 ± 0.16, p = 0.004; anxiety difference 1.30 ± 0.22; p < 0.001). Patients experienced more pain (1.05 ± 0.12; p < 0.001) and anxiety (1.22 ± 0.15; p < 0.001) after placement of IMD. Radiographers are more cautious, more anxious and use less compression during mammography of breasts with IMD. CONCLUSION: Image quality in a breast with an IMD could be improved by projecting more breast tissue on the mammogram, thereby including (part of) the IMD between the paddles, if required. In addition, radiographers should pay sufficient attention to reducing discomfort both before and during the screening examination. ADVANCES IN KNOWLEDGE: Little is known about the quality of mammography in females with an IMD or how these females and radiographers experience the screening examination. The results of our study showed that having an IMD could result in a suboptimal mammogram and increased discomfort.

Value of audits in breast cancer screening quality assurance programmes.

OBJECTIVES: Our aim was to retrospectively evaluate the results of all audits performed in the past and to assess their value in the quality assurance of the Dutch breast cancer screening programme. METHODS: The audit team of the Dutch Reference Centre for Screening (LRCB) conducts triennial audits of all 17 reading units. During audits, screening outcomes like recall rates and detection rates are assessed and a radiological review is performed. This study investigates and compares the results of four audit series: 1996-2000, 2001-2005, 2003-2007 and 2010-2013. RESULTS: The analysis shows increased recall rates (from 0.66%, 1.07%, 1.22% to 1.58%), increased detection rates (from 3.3, 4.5, 4.8 to 5.4 per 1000) and increased sensitivity (from 64.5%, 68.7%, 70.5% to 71.6%), over the four audit series. The percentage of 'missed cancers' among interval cancers and advanced screen-detected cancers did not change (p = 0.4). CONCLUSIONS: Our audits not only provide an opportunity for assessing screening outcomes, but also provide moments of self-reflection with peers. For radiologists, an accurate understanding of their performance is essential to identify points of improvement. We therefore recommend a radiological review of screening examinations and immediate feedback as part of an audit. KEY POINTS: • Radiological review and immediate feedback are recommended as part of an audit. • For breast screening radiologists, audits provide moments of self-reflection with peers. • Radiological review of screening examinations provides insights in recall behaviour. • Accurate understanding of radiologists' performance is essential to identify points of improvement.

Comparison of a flexible versus a rigid breast compression paddle: pain experience, projected breast area, radiation dose and technical image quality.

PURPOSE: To compare pain, projected breast area, radiation dose and image quality between flexible (FP) and rigid (RP) breast compression paddles. METHODS: The study was conducted in a Dutch mammographic screening unit (288 women). To compare both paddles one additional image with RP was made, consisting of either a mediolateral-oblique (MLO) or craniocaudal-view (CC). Pain experience was scored using the Numeric Rating Scale (NRS). Projected breast area was estimated using computer software. Radiation dose was estimated using the model by Dance. Image quality was reviewed by three radiologists and three radiographers. RESULTS: There was no difference in pain experience between both paddles (mean difference NRS: 0.08 ± 0.08, p = 0.32). Mean radiation dose was 4.5 % lower with FP (0.09 ± 0.01 p = 0.00). On MLO-images, the projected breast area was 0.79 % larger with FP. Paired evaluation of image quality indicated that FP removed fibroglandular tissue from the image area and reduced contrast in the clinically relevant retroglandular area at chest wall side. CONCLUSIONS: Although FP performed slightly better in the projected breast area, it moved breast tissue from the image area at chest wall side. RP showed better contrast, especially in the retroglandular area. We therefore recommend the use of RP for standard MLO and CC views.

Breast cancer screening halves the risk of breast cancer death: a case-referent study.

Large-scale epidemiologic studies have consistently demonstrated the effectiveness of mammographic screening programs, however the benefits are still subject to debate. We estimated the effect of the Dutch screening program on breast cancer mortality. In a large multi-region case-referent study, we identified all breast cancer deaths in 2004 and 2005 in women aged 50-75 who had been invited for screening (cases). Cases were individually matched to referents from the population invited to screening. Conditional logistic regression was used to estimate the odds ratio (OR) of breast cancer death according to individual screening history. The OR was adjusted for self-selection bias using regional correction factors for the difference in baseline risk for breast cancer death between screened and unscreened women. A total of 1233 cases and 2090 referents were included in this study. We found a 58% reduction in breast cancer mortality in screened versus unscreened women (adjusted OR = 0.42, 95% CI 0.33-0.53). Screening, i.e. early detection and treatment, has resulted in a substantial reduction in breast cancer mortality, indicating that the Dutch breast cancer screening program is highly effective.

The impact of mammographic screening on breast cancer mortality in Europe: a review of observational studies.

OBJECTIVES: To assess the impact of population-based mammographic screening on breast cancer mortality in Europe, considering different methodologies and limitations of the data. METHODS: We conducted a systematic literature review of European trend studies (n = 17), incidence-based mortality (IBM) studies (n = 20) and case-control (CC) studies (n = 8). Estimates of the reduction in breast cancer mortality for women invited versus not invited and/or for women screened versus not screened were obtained. The results of IBM studies and CC studies were each pooled using a random effects meta-analysis. RESULTS: Twelve of the 17 trend studies quantified the impact of population-based screening on breast cancer mortality. The estimated breast cancer mortality reductions ranged from 1% to 9% per year in studies reporting an annual percentage change, and from 28% to 36% in those comparing post- and prescreening periods. In the IBM studies, the pooled mortality reduction was 25% (relative risk [RR] 0.75, 95% confidence interval [CI] 0.69-0.81) among invited women and 38% (RR 0.62, 95% CI 0.56-0.69) among those actually screened. The corresponding pooled estimates from the CC studies were 31% (odds ratio [OR] 0.69, 95% CI 0.57-0.83), and 48% (OR 0.52, 95% CI 0.42-0.65) adjusted for self-selection. CONCLUSIONS: Valid observational designs are those where sufficient longitudinal individual data are available, directly linking a woman's screening history to her cause of death. From such studies, the best 'European' estimate of breast cancer mortality reduction is 25-31% for women invited for screening, and 38-48% for women actually screened. Much of the current controversy on breast cancer screening is due to the use of inappropriate methodological approaches that are unable to capture the true effect of mammographic screening.

Minor influence of self-selection bias on the effectiveness of breast cancer screening in case-control studies in the Netherlands.

BACKGROUND: Self-selection bias is considered to be a problem when evaluating the effectiveness of breast cancer service screening in case-control studies. OBJECTIVE: Using the incidence-based mortality method (IBM), a correction factor for the potential influence of self-selection can be derived from a group of non-screened women and a group of not-invited women. METHODS: Breast cancer patients, diagnosed in 1990-1995 and between the ages of 50 to 70, were selected from the Netherlands Cancer Registry and five screening regions in the Netherlands. Person-years were calculated for non-screened and not-invited women by using population data available on the number of women invited, the number of women screened and the total population. Incidence-based breast cancer mortality rates according to screening status were calculated for the five screening regions. RESULTS: Between 1990-1995, 15,541 patients were diagnosed with breast cancer. An analysis of ten-year follow-up after diagnosis resulted in 3903 breast cancer deaths, of which 2631 were not-invited and 345 were non-screened. Poisson regression analysis showed heterogeneity between the regions with a range of IBM ratios from 0.64 (95% CI: 0.46-0.90) to 1.08 (95% CI: 0.82-1.43). CONCLUSIONS: Heterogeneity between the regions stresses the importance of a country- and/or region- specific estimate of self-selection. Adjusting for self-selection bias in the regional case-control studies would not change the breast cancer mortality reduction in three regions and would result in an even larger effect in two regions. Looking at the range of IBM ratios the overall influence of self-selection in the Netherlands is minor.

Residual confounding after adjustment for age: a minor issue in breast cancer screening effectiveness.

Residual confounding, after adjustment for age, is the major criticism of observational studies on breast cancer screening effectiveness. We developed realistic scenarios for the prevalence and strength of risk factors on screened and not screened groups, and explored the impact of residual confounding bias. Our results demonstrate that residual confounding bias is a minor issue in screening programme evaluations.

Effective biennial mammographic screening in women aged 40-49.

BACKGROUND: The United Kingdom is currently moving the age limit for invitation in its national breast screening programme downwards from 50 to 47. In contrast, the US Preventive Services Task Force concluded that, because of borderline statistical significance on effectiveness of mammographic screening, the current evidence is insufficient to advise screening in women aged 40-49. MATERIAL AND METHODS: We designed a case-referent study to investigate the effect of biennial mammographic screening on breast cancer mortality for women in their forties. In Nijmegen, the Netherlands, screening started in 1975. A total of 272 breast cancer deaths were identified, and 1360 referents aged 40-69 were sampled from the population invited for screening. Effectiveness was estimated by calculating the odds ratio (OR) indicating the breast cancer death rate in screened versus unscreened women. RESULTS: In women aged 40-49, the effect of screening was OR = 0.50 (95% confidence interval (CI) = 0.30-0.82). This result is similar to those aged 50-59 (OR = 0.54; 95% CI = 0.35-0.85) and 60-69 (OR = 0.65; 95% CI = 0.38-1.13). CONCLUSION: Our results add convincing evidence about the effectiveness of biennial mammographic screening in women aged 40-49.

A remarkable reduction of breast cancer deaths in screened versus unscreened women: a case-referent study.

OBJECTIVE: We designed a case-referent study to investigate the effect of mammographic screening at the individual level, looking at the association of breast cancer death with screening history. METHODS: The study population included all women aged 50-75 in the province of Limburg, the Netherlands who had been invited to the screening program from 1989 to 2006. From this population, 118 cases originated who died of breast cancer in 2004 or 2005. The screening history of these cases was collected and compared with a sample of the invited population. The breast cancer death rate in the screened relative to the unscreened women was estimated as the odds ratio (OR). This OR was adjusted for self-selection bias, the difference in baseline risk for breast cancer death between screened and unscreened women. RESULTS: Analysis of the data showed a breast cancer mortality reduction of 70% in the screened versus the unscreened women (OR = 0.30, 95% CI 0.14-0.63). The magnitude of self-selection was estimated specifically for Limburg. After correction for self-selection bias, the effect of screening increased to 76% (OR = 0.24, 95% CI 0.10-0.58). CONCLUSION: Screening resulted in a remarkable reduction in breast cancer mortality. Contrary to findings in other countries, adjustment for self-selection in Limburg had no influence on the impact of screening. Thanks to a well-organized centralized screening program, similar results are expected in other regions of the Netherlands.