Biomedical subjects

Linn A Abraham

Publications and source records attributed to Linn A Abraham.

8 recordsLinked to original sources

PubMed2006

Performance benchmarks for screening mammography.

PURPOSE: To retrospectively evaluate the range of performance outcomes of the radiologist in an audit of screening mammography by using a representative sample of U.S. radiologists to allow development of performance benchmarks for screening mammography. MATERIALS AND METHODS: Institutional review board approval was obtained, and study was HIPAA compliant. Informed consent was or was not obtained according to institutional review board guidelines. Data from 188 mammographic facilities and 807 radiologists obtained between 1996 and 2002 were analyzed from six registries from the Breast Cancer Surveillance Consortium (BCSC). Contributed data included demographic information, clinical findings, mammographic interpretation, and biopsy results. Measurements calculated were positive predictive values (PPVs) from screening mammography (PPV(1)), biopsy recommendation (PPV(2)), biopsy performed (PPV(3)), recall rate, cancer detection rate, mean cancer size, and cancer stage. Radiologist performance data are presented as 50th (median), 10th, 25th, 75th, and 90th percentiles and as graphic presentations by using smoothed curves. RESULTS: There were 2 580 151 screening mammographic studies from 1 117 390 women (age range, <30 to >/=80 years). The respective means and ranges of performance outcomes for the middle 50% of radiologists were as follows: recall rate, 9.8% and 6.4%-13.3%; PPV(1), 4.8% and 3.4%-6.2%; and PPV(2), 24.6% and 18.8%-32.0%. Mean cancer detection rate was 4.7 per 1000, and the median [corrected] mean size of invasive cancers was 13 mm. The range of performance outcomes for the middle 80% of radiologists also was presented. CONCLUSION: Community screening mammographic performance measurements of cancer outcomes for the majority of radiologists in the BCSC surpass performance recommendations. Recall rate for almost half of radiologists, however, is higher than the recommended rate.

Adult↗

PubMed2005

Current realities of delivering mammography services in the community: do challenges with staffing and scheduling exist?

PURPOSE: To evaluate the current (2001-2002) capacity of community-based mammography facilities to deliver screening and diagnostic services in the United States. MATERIALS AND METHODS: Institutional review board approvals and patient consent were obtained. A mailed survey was sent to 53 eligible mammography facilities in three states (Washington, New Hampshire, and Colorado). Survey questions assessed equipment and staffing availability, as well as appointment waiting times for screening and diagnostic mammography services. Criterion-related content and construct validity were obtained first by means of a national advisory committee of academic, scientific, and clinical colleagues in mammography that reviewed literature on existing surveys and second by pilot testing a series of draft surveys among community mammography facilities not inclusive of the study facilities. The final survey results were independently double entered into a relational database with programmed data checks. The data were sent encrypted by means of file transfer protocol to a central analytical center at Group Health Cooperative. A two-sided P value with alpha = .05 was considered to show statistical significance in all analyses. RESULTS: Forty-five of 53 eligible mammography facilities (85%) returned the survey. Shortages of radiologists relative to the mammographic volume were found in 44% of mammography facilities overall, with shortages of radiologists higher in not-for-profit versus for-profit facilities (60% vs 28% reported). Shortages of Mammography Quality Standards Act-qualified technologists were reported by 20% of facilities, with 46% reporting some level of difficulty in maintaining qualified technologists. Waiting times for diagnostic mammography ranged from less than 1 week to 4 weeks, with 85% performed within 1 week. Waiting times for screening mammography ranged from less than 1 week to 8 weeks, with 59% performed between 1 week and 4 weeks. Waiting times for both diagnostic and screening services were two to three times higher in high-volume compared with low-volume facilities. CONCLUSION: Survey results show shortages of radiologists and certified mammography technologists.

Breast Neoplasms↗

PubMed2005

Breast cancer yield for screening mammographic examinations with recommendation for short-interval follow-up.

PURPOSE: To compare cancer yield for screening examinations with recommendation for short-interval follow-up after diagnostic imaging work-up versus after screening mammography only. MATERIALS AND METHODS: From January 1996 to December 1999, Breast Imaging Reporting and Data System assessments and recommendations were collected prospectively for 1,171,792 screening examinations in 758,015 women aged 40-89 years at seven mammography registries in Breast Cancer Surveillance Consortium. Registries obtained waiver of signed consent or collected signed consent in accordance with institutional review boards at each location. Diagnosis of invasive cancer or ductal carcinoma in situ within 24 months of screening examination and tumor stage and size for invasive cancer were determined through linkage to pathology database or tumor registry. chi2 test was used to determine significant differences between groups. RESULTS: Overall, 5.2% of first and 1.7% of subsequent screens included recommendation for short-interval follow-up, which was similar to likelihood of recommendation for diagnostic evaluation (first screens, 4.6%; subsequent, 2.6%). Most recommendations for short-interval follow-up were based on screening mammography alone (86.2% of first screens, 77.5% of subsequent). Yield of cancer for screening examinations with probably benign finding (PBF) and recommendation for short-interval follow-up based on screening mammography alone tended to be lower than in those with PBF and recommendation for short-interval follow-up after additional work-up (first screens: 0.54% vs 0.96%, P=.10; subsequent: 1.50% vs 1.73%, P=.26). Proportion of stage II and higher disease tended to be higher for examinations with PBF and recommendation for short-interval follow-up based on screening mammography alone compared with those recommended for short-interval follow-up after additional work-up (first screens: 34.7% vs 24.4%, P=.43; subsequent: 27.5% vs 19.2%, P=.13). CONCLUSION: Many first screening examinations include recommendation for short-interval follow-up based on screening mammography alone. Cancer yield for these examinations is low and is lower than that with diagnostic work-up prior to short-interval follow-up recommendation. Absence of diagnostic work-up prior to short-interval follow-up recommendation may result in periodic surveillance of a high proportion of benign lesions.

Adult↗

PubMed2005

Does litigation influence medical practice? The influence of community radiologists' medical malpractice perceptions and experience on screening mammography.

PURPOSE: To assess the relationship between radiologists' perception of and experience with medical malpractice and their patient-recall rates in actual community-based clinical settings. MATERIALS AND METHODS: All study activities were approved by the institutional review boards of the involved institutions, and patient and radiologist informed consent was obtained where necessary. This study was performed in three regions of the United States (Washington, Colorado, and New Hampshire). Radiologists who routinely interpret mammograms completed a mailed survey that included questions on demographic data, practice environment, and medical malpractice. Survey responses were linked to interpretive performance for all screening mammography examinations performed between January 1, 1996, and December 31, 2001. The odds of recall were modeled by using logistic regression analysis based on generalized estimating equations that adjust for study region. RESULTS: Of 181 eligible radiologists, 139 (76.8%) returned the survey with full consent. The analysis included 124 radiologists who had interpreted a total of 557 143 screening mammograms. Approximately half (64 of 122 [52.4%]) of the radiologists reported a prior malpractice claim, with 18 (14.8%) reporting mammography-related claims. The majority (n = 51 [81.0%]) of the 63 radiologists who responded to a question regarding the degree of stress caused by a medical malpractice claim described the experience as very or extremely stressful. More than three of every four radiologists (ie, 94 [76.4%] of 123) expressed concern about the impact medical malpractice has on mammography practice, with over half (72 [58.5%] of 123) indicating that their concern moderately to greatly increased the number of their recommendations for breast biopsies. Radiologists' estimates of their future malpractice risk were substantially higher than the actual historical risk. Almost one of every three radiologists (43 of 122 [35.3%]) had considered withdrawing from mammogram interpretation because of malpractice concerns. No significant association was found between recall rates and radiologists' experiences or perceptions of medical malpractice. CONCLUSION: U.S. radiologists are extremely concerned about medical malpractice and report that this concern affects their recall rates and biopsy recommendations. However, medical malpractice experience and concerns were not associated with recall or false-positive rates. Heightened concern of almost all radiologists may be a key reason that recall rates are higher in the United States than in other countries, but this hypothesis requires further study.

Adult↗

PubMed2004

The association between obesity and screening mammography accuracy.

BACKGROUND: Obesity is increasing among American women, especially as they age. The influence of obesity on the accuracy of screening mammography has not been studied extensively. METHODS: We analyzed 100 622 screening mammography examinations performed on members of a nonprofit health plan. The relationship between body mass index (weight in kilograms divided by the square of height in meters) and measures of screening accuracy was assessed. Body mass index was categorized as underweight or normal weight (<25), overweight (25-29), obesity class I (30-34), and obesity classes II to III (> or =35). RESULTS: Compared with underweight or normal weight women, overweight and obese women were more likely to be recalled for additional tests after adjusting for important covariates, including age and breast density (overweight odds ratio [OR], 1.17; 95% confidence interval [CI], 1.11-1.23); obesity class I OR, 1.27; 95% CI, 1.19-1.35; obesity classes II-III OR, 1.31; 95% CI, 1.22-1.41). As body mass index increased, women were more likely to have lower specificity (overweight OR, 0.86; 95% CI, 0.81-0.90; obesity class I OR, 0.79; 95% CI, 0.74-0.84; and obesity classes II-III OR, 0.77; 95% CI, 0.71-0.82). No statistically significant differences were noted in sensitivity. Adjusted receiver operating characteristic analysis showed statistically significant improvement in the area under the curve (AUC) for underweight or normal weight women (AUC = 0.941) vs overweight women (AUC = 0.916, P =.02) and underweight or normal weight women vs obesity classes II and III women (AUC = 0.904, P =.02). CONCLUSIONS: Obese women had more than a 20% increased risk of having false-positive mammography results compared with underweight and normal weight women, although sensitivity was unchanged. Achieving a normal weight may improve screening mammography performance.

Adult↗

PubMed2003

Individual and combined effects of age, breast density, and hormone replacement therapy use on the accuracy of screening mammography.

BACKGROUND: The relationships among breast density, age, and use of hormone replacement therapy (HRT) in breast cancer detection have not been fully evaluated. OBJECTIVE: To determine how breast density, age, and use of HRT individually and in combination affect the accuracy of screening mammography. DESIGN: Prospective cohort study. SETTING: 7 population-based mammography registries in North Carolina; New Mexico; New Hampshire; Vermont; Colorado; Seattle, Washington; and San Francisco, California. PARTICIPANTS: 329 495 women 40 to 89 years of age who had 463 372 screening mammograms from 1996 to 1998; 2223 women received a diagnosis of breast cancer. MEASUREMENTS: Breast density, age, HRT use, rate of breast cancer occurrence, and sensitivity and specificity of screening mammography. RESULTS: Adjusted sensitivity ranged from 62.9% in women with extremely dense breasts to 87.0% in women with almost entirely fatty breasts; adjusted sensitivity increased with age from 68.6% in women 40 to 44 years of age to 83.3% in women 80 to 89 years of age. Adjusted specificity increased from 89.1% in women with extremely dense breasts to 96.9% in women with almost entirely fatty breasts. In women who did not use HRT, adjusted specificity increased from 91.4% in women 40 to 44 years of age to 94.4% in women 80 to 89 years of age. In women who used HRT, adjusted specificity was about 91.7% for all ages. CONCLUSIONS: Mammographic breast density and age are important predictors of the accuracy of screening mammography. Although HRT use is not an independent predictor of accuracy, it probably affects accuracy by increasing breast density.

Adipose Tissue↗

PubMed2003

Mammography surveillance following breast cancer.

BACKGROUND: To describe when women diagnosed with breast cancer return for their first mammography, and to identify factors predictive of women returning for mammographic surveillance. METHODS: Women who underwent mammography at facilities participating in the National Cancer Institute's Breast Cancer Surveillance Consortium (BCSC) during 1996 and who were subsequently diagnosed with ductal carcinoma in situ or invasive breast cancer were included in this study. Data from seven mammography registries were linked to population-based cancer and pathology registries. Kaplan-Meier curves were used to depict the number of months from the breast cancer diagnosis to the first mammogram within the defined follow-up period. Demographic, disease and treatment variables were included in univariate and multivariate analyses to identify factors predictive of women returning for mammography. RESULTS: Of the 2503 women diagnosed with breast cancer, 78.1% returned for mammography examination between 7 and 30 months following the diagnosis. Mammography facilities indicated that 66.8% of mammography examinations were classified as screening. Multivariate analyses found that women were most likely to undergo surveillance mammography if they were diagnosed at ages 60-69 with Stage 0, I or II breast cancer and had received radiation therapy in addition to surgery. CONCLUSIONS: While the majority of women return for mammographic surveillance following breast cancer, some important subgroups of women at higher risk for recurrence are less likely to return. Research is needed to determine why some women are not undergoing mammography surveillance after a breast cancer diagnosis and whether surveillance increases the chance of detecting tumors with a good prognosis.

Adult↗

PubMedDate not supplied

Radiologist uncertainty and the interpretation of screening.

OBJECTIVE: To determine radiologists' reactions to uncertainty when interpreting mammography and the extent to which radiologist uncertainty explains variability in interpretive performance. METHODS: The authors used a mailed survey to assess demographic and clinical characteristics of radiologists and reactions to uncertainty associated with practice. Responses were linked to radiologists' actual interpretive performance data obtained from 3 regionally located mammography registries. RESULTS: More than 180 radiologists were eligible to participate, and 139 consented for a response rate of 76.8%. Radiologist gender, more years interpreting, and higher volume were associated with lower uncertainty scores. Positive predictive value, recall rates, and specificity were more affected by reactions to uncertainty than sensitivity or negative predictive value; however, none of these relationships was statistically significant. CONCLUSION: Certain practice factors, such as gender and years of interpretive experience, affect uncertainty scores. Radiologists' reactions to uncertainty do not appear to affect interpretive performance.

Colorado↗