Temporal trends in healthcare utilization following primary melanoma diagnosis among Medicare beneficiaries.

BACKGROUND: Little is known about the impact of primary melanoma diagnosis on healthcare utilization and changes in utilization over time. OBJECTIVES: To evaluate population-based temporal trends in healthcare utilization following primary melanoma diagnosis. METHODS: We conducted a before-and-after multiple time series study of Medicare beneficiaries aged ≥ 66 years with primary melanoma diagnoses between 2000 and 2009 using the Surveillance, Epidemiology, and End Results Medicare database. Primary exposure was time from primary melanoma diagnosis at 3-6 months and 6-24 months postdiagnosis. Covariates included tumour-, patient- and geographical-level characteristics and healthcare utilization in the 6 months before diagnosis. Poisson regression was used to estimate population-based risk-adjusted utilization rates for skin biopsies, benign skin excisions, internal medicine office visits and dermatology office visits. RESULTS: The study population included 56 254 patients with first diagnoses of primary melanoma. Most patients were ≥ 75 years old (56·8%), male (62·1%), and had in situ melanoma (42·4%) or localized invasive melanoma (45·9%). From 2000 to 2009, risk-adjusted skin biopsy rates 24 months postdiagnosis increased from 358·3 to 541·3 per 1000 person-years (P < 0·001), and dermatology visits increased from 989·0 to 1535·6 per 1000 person-years (P < 0·001). Benign excisions and internal medicine visits remained stable. In 2000, risk-adjusted skin biopsy rates 6 months postdiagnosis increased by 208·5 relative to the 6 months before diagnosis (148·7 vs. 357·2) compared with an observed absolute increase of 272·5 (290·9 vs. 563·1) in 2009. Trends in dermatology visits were similar. CONCLUSIONS: Utilization of skin biopsies and dermatology office visits following primary melanoma diagnosis has increased substantially over time. These results may inform optimization of care delivery for melanoma within the Medicare population.

Skin biopsy utilization and melanoma incidence among Medicare beneficiaries.

BACKGROUND: Melanoma incidence has increased in recent decades in the U.S.A. Uncertainty remains regarding how much of this increase is attributable to greater melanoma screening activities, potential detection bias and overdiagnosis. OBJECTIVES: To use a cross-sectional ecological analysis to evaluate the relationship between skin biopsy and melanoma incidence rates over a more recent time period than prior reports. METHODS: Examination of the association of biopsy rates and melanoma incidence (invasive and in situ) in SEER-Medicare data (including 10 states) for 2002-2009. RESULTS: The skin biopsy rate increased by approximately 50% (6% per year) throughout this 8-year period, from 7012 biopsies per 100 000 persons in 2002 to 10 528 biopsies per 100 000 persons in 2009. The overall melanoma incidence rate increased approximately 4% (< 1% per year) over the same time period. The incidence of melanoma in situ increased approximately 10% (1% per year), while the incidence of invasive melanoma increased from 2002 to 2005 then decreased from 2006 to 2009. Regression models estimated that, on average, for every 1000 skin biopsies performed, an additional 5·2 (95% confidence interval 4·1-6·3) cases of melanoma in situ were diagnosed and 8·1 (95% confidence interval 6·7-9·5) cases of invasive melanoma were diagnosed. When considering individual states, some demonstrated a positive association between biopsy rate and invasive melanoma incidence, others an inverse association, and still others a more complex pattern. CONCLUSIONS: Increased skin biopsies over time are associated with increased diagnosis of in situ melanoma, but the association with invasive melanoma is more complex.

Performance assessment for radiologists interpreting screening mammography.

When interpreting screening mammograms radiologists decide whether suspicious abnormalities exist that warrant the recall of the patient for further testing. Previous work has found significant differences in interpretation among radiologists; their false-positive and false-negative rates have been shown to vary widely. Performance assessments of individual radiologists have been mandated by the U.S. government, but concern exists about the adequacy of current assessment techniques. We use hierarchical modelling techniques to infer about interpretive performance of individual radiologists in screening mammography. While doing this we account for differences due to patient mix and radiologist attributes (for instance, years of experience or interpretive volume). We model at the mammogram level, and then use these models to assess radiologist performance. Our approach is demonstrated with data from mammography registries and radiologist surveys. For each mammogram, the registries record whether or not the woman was found to have breast cancer within one year of the mammogram; this criterion is used to determine whether the recall decision was correct. We model the false-positive rate and the false-negative rate separately using logistic regression on patient risk factors and radiologist random effects. The radiologist random effects are, in turn, regressed on radiologist attributes such as the number of years in practice. Using these Bayesian hierarchical models we examine several radiologist performance metrics. The first is the difference between the false-positive or false-negative rate of a particular radiologist and that of a hypothetical 'standard' radiologist with the same attributes and the same patient mix. A second metric predicts the performance of each radiologist on hypothetical mammography exams with particular combinations of patient risk factors (which we characterize as 'typical', 'high-risk', or 'low-risk'). The second metric can be used to compare one radiologist to another, while the first metric addresses how the radiologist is performing compared to an appropriate standard. Interval estimates are given for the metrics, thereby addressing uncertainty. The particular novelty in our contribution is to estimate multiple performance rates (sensitivity and specificity). One can even estimate a continuum of performance rates such as a performance curve or ROC curve using our models and we describe how this may be done. In addition to assessing radiologists in the original data set, we also show how to infer about the performance of a new radiologist with new case mix, new outcome data, and new attributes without having to refit the model.

Hormone replacement therapy after a diagnosis of breast cancer in relation to recurrence and mortality.

BACKGROUND: Hormone replacement therapy (HRT) is typically avoided for women with a history of breast cancer because of concerns that estrogen will stimulate recurrence. In this study, we sought to evaluate the impact of HRT on recurrence and mortality after a diagnosis of breast cancer. METHODS: Data were assembled from 2755 women aged 35-74 years who were diagnosed with incident invasive breast cancer while they were enrolled in a large health maintenance organization from 1977 through 1994. Pharmacy data identified 174 users of HRT after diagnosis. Each HRT user was matched to four randomly selected nonusers of HRT with similar age, disease stage, and year of diagnosis. Women in the analysis were recurrence free at HRT initiation or the equivalent time since diagnosis. Rates of recurrence and death through 1996 were calculated. Adjusted relative risks were estimated by use of the Cox regression model. All statistical tests were two-sided. RESULTS: The rate of breast cancer recurrence was 17 per 1000 person-years in women who used HRT after diagnosis and 30 per 1000 person-years in nonusers (adjusted relative risk for users compared with nonusers = 0.50; 95% confidence interval [CI] = 0.30 to 0.85). Breast cancer mortality rates were five per 1000 person-years in HRT users and 15 per 1000 person-years in nonusers (adjusted relative risk = 0.34; 95% CI = 0.13 to 0.91). Total mortality rates were 16 per 1000 person-years in HRT users and 30 per 1000 person-years in nonusers (adjusted relative risk = 0.48; 95% CI = 0.29 to 0.78). The relatively low rates of recurrence and death were observed in women who used any type of HRT (oral only = 41% of HRT users; vaginal only = 43%; both oral and vaginal = 16%). No trend toward lower relative risks was observed with increased dose. CONCLUSION: We observed lower risks of recurrence and mortality in women who used HRT after breast cancer diagnosis than in women who did not. Although residual confounding may exist, the results suggest that HRT after breast cancer has no adverse impact on recurrence and mortality.

Increased patient concern after false-positive mammograms: clinician documentation and subsequent ambulatory visits.

OBJECTIVE: To measure how often a breast-related concern was documented in medical records after screening mammography according to the mammogram result (normal, or true-negative vs false-positive) and to measure changes in health care utilization in the year after the mammogram. DESIGN: Cohort study. SETTING: Large health maintenance organization in New England. PATIENTS: Group of 496 women with false-positive screening mammograms and a comparison group of 496 women with normal screening mammograms, matched for location and year of mammogram. MEASUREMENTS AND MAIN RESULTS: 1) Documentation in clinicians' notes of patient concern about the breast and 2) ambulatory health care utilization, both breast-related and non-breast-related, in the year after the mammogram. Fifty (10%) of 496 women with false-positive mammograms had documentation of breast-related concern during the 12 months after the mammogram, compared to 1 (0.2%) woman with a normal mammogram (P =.001). Documented concern increased with the intensity of recommended follow-up (P =.009). Subsequent ambulatory visits, not related to the screening mammogram, increased in the year after the mammogram among women with false-positive mammograms, both in terms of breast-related visits (incidence ratio, 3.07; 95% confidence interval [CI], 1.69 to 5.93) and non-breast-related visits (incidence ratio, 1.14; 95% CI, 1.03 to 1.25). CONCLUSIONS: Clinicians document concern about breast cancer in 10% of women who have false-positive mammograms, and subsequent use of health care services are increased among women with false-positive mammogram results.

Journal reading habits of internists.

We assessed the reading habits of internists with and without epidemiological training because such information may help guide medical journals as they make changes in how articles are edited and formatted. In a 1998 national self-administered mailed survey of 143 internists with fellowship training in epidemiology and study design and a random sample of 121 internists from the American Medical Association physician master file, we asked about the number of hours spent reading medical journals per week and the percentage of articles for which only the abstract is read. Respondents also were asked which of nine medical journals they subscribe to and read regularly. Of the 399 eligible participants, 264 returned surveys (response rate 66%). Respondents reported spending 4.4 hours per week reading medical journal articles and reported reading only the abstract for 63% of the articles; these findings were similar for internists with and without epidemiology training. Respondents admitted to a reliance on journal editors to provide rigorous and useful information, given the limited time available for critical reading. We conclude that internists, regardless of training in epidemiology, rely heavily on abstracts and prescreening of articles by editors.

Predicting the cumulative risk of false-positive mammograms.

BACKGROUND: The cumulative risk of a false-positive mammogram can be substantial. We studied which variables affect the chance of a false-positive mammogram and estimated cumulative risks over nine sequential mammograms. METHODS: We used medical records of 2227 randomly selected women who were 40-69 years of age on July 1, 1983, and had at least one screening mammogram. We used a Bayesian discrete hazard regression model developed for this study to test the effect of patient and radiologic variables on a first false-positive screening and to calculate cumulative risks of a false-positive mammogram. RESULTS: Of 9747 screening mammograms, 6. 5% were false-positive; 23.8% of women experienced at least one false-positive result. After nine mammograms, the risk of a false-positive mammogram was 43.1% (95% confidence interval [CI] = 36.6%-53.6%). Risk ratios decreased with increasing age and increased with number of breast biopsies, family history of breast cancer, estrogen use, time between screenings, no comparison with previous mammograms, and the radiologist's tendency to call mammograms abnormal. For a woman with highest-risk variables, the estimated risk for a false-positive mammogram at the first and by the ninth mammogram was 98.1% (95% CI = 69.3%-100%) and 100% (95% CI = 99.9%-100%), respectively. A woman with lowest-risk variables had estimated risks of 0.7% (95% CI = 0.2%-1.9%) and 4.6% (95% CI = 1. 1%-12.5%), respectively. CONCLUSIONS: The cumulative risk of a false-positive mammogram over time varies substantially, depending on a woman's own risk profile and on several factors related to radiologic screening. By the ninth mammogram, the risk can be as low as 5% for women with low-risk variables and as high as 100% for women with multiple high-risk factors.

Do physicians judge a study by its cover? An investigation of journal attribution bias.

The effect of a journal's prestige on readers' impressions of an article is unknown. Two hypotheses were tested: first, that attribution of a study to a "high" prestige journal would be associated with improved impressions and attribution to a "low" prestige journal would be associated with diminished impressions; and second, that formal training in epidemiology and biostatistics would mitigate the effects of this journal attribution bias. The study was designed as a trial among a random sample of 264 internists. Participants were asked to read an article and an abstract from either the Southern Medical Journal (SMJ) or the New England Journal of Medicine (NEJM). Questionnaires were constructed that either attributed the article or abstract to its source or presented it as unattributed. After each article or abstract, respondents were asked to rate the quality of the study, the appropriateness of the methodology employed, the significance of the findings, and its likely effects on their practice. A 20-point impression score was created based on responses to these statements. The effect of attribution to a specific journal and formal epidemiology training on impression scores were assessed using linear regression. Of the 399 eligible participants, 264 questionnaires were returned (response rate 66%). Differences in impression scores associated with attribution of an article or abstract to the NEJM were.71 [95% C.I. (-.44-1.87)] and.50 [95% C.I. (-.87-1.87)] respectively; differences in impression scores associated with attribution of an article or abstract to the SMJ were -.12 [95% C.I. (-1.53-1.30)] and -.95 [95% C.I. (-2.41-.52)]. A stratified analysis demonstrated that epidemiology training did not meaningfully alter the effect of journal attribution on participants' impression scores. If journal attribution bias exists, it is likely to exert small and clinically insignificant effects when physicians read articles carefully. Formal training in epidemiology and biostatistics does not appear to alter these results.

Accuracy of screening mammography using single versus independent double interpretation.

OBJECTIVE: We conducted an analysis among 31 community radiologists to identify the average change in screening mammography interpretive accuracy afforded by independent double interpretation. MATERIALS AND METHODS: We assessed interpretive accuracy using a stratified random sample of test mammograms that included 30 women with cancer and 83 without. Radiologists were unaware of clinical information and of each other's assessments. We describe accuracy for individual radiologists and for double interpretation, including average sensitivity, specificity, diagnostic likelihood ratios positive and negative, and area under the receiver operating characteristic (ROC) curve. We also assessed weighted and nonweighted kappa statistics among all 465 pairs of radiologists and 31,465 pairs of unique pairs. The assessment for double interpretations used the "highest" (i.e., most abnormal) assessment of the two radiologists. We calculated the difference between each radiologist's individual accuracy and the average accuracy across that radiologist's 30 double interpretations. RESULTS: We found the following average accuracy statistics for individual radiologists: sensitivity, 79%; specificity, 81%; diagnostic likelihood ratio positive, 5.53; diagnostic likelihood ratio negative, 0.26; and area under the ROC curve, 0.85. The mean kappa statistic among radiologists for cancer cases increased with double interpretation from 0.59 to 0.70, and for noncancer cases from 0.30 to 0.34. Double interpretation resulted in an average increase in sensitivity of 7%, an average decrease in specificity of 11%, a decrease in diagnostic likelihood ratio positive of 2.35, a decrease in diagnostic likelihood ratio negative of 0.06, and an increase in area under the ROC curve of 0.02. CONCLUSION: Independent double interpretation does not increase accuracy as measured by the area under the ROC curve.

Breast cancer screening use by African Americans and Whites in an HMO.

OBJECTIVE: To examine racial differences in breast cancer screening in an HMO that provides screening at no cost. DESIGN: Retrospective cohort study of breast cancer screening among African-American and white women. Breast cancer screening information was extracted from computerized medical records. SETTING: A large HMO in New England. PATIENTS/PARTICIPANTS: White and African-American women (N = 2,072) enrolled for at least 10 years in the HMO. MAIN RESULTS: Primary care clinicians documented recommending a screening mammogram significantly more often for African Americans than whites (70% vs 64%; P <.001). During the 10-year period, on average, white women obtained more mammograms (4.49 vs 3.93; P <.0001) and clinical breast examinations (5.35 vs 4.92; P <.01) than African-American women. However, a woman's race was no longer a statistically significant predictor of breast cancer screening after adjustment for differences in age, estimated household income, estrogen use, and body mass index (adjusted number of mammograms, 4.47 vs 4.25, P =.17; and adjusted number of clinical breast examinations, 5.35 vs 5. 31, P =.87). CONCLUSIONS: In this HMO, African-American and white women obtained breast cancer screening at similar rates. Comparisons with national data showed much higher screening rates in this HMO for both white and African-American women.

Effect of false-positive mammograms on interval breast cancer screening in a health maintenance organization.

BACKGROUND: Despite the mortality benefits of breast cancer screening, not all women receive regular mammography. Such factors as age, socioeconomic status, and physician recommendation have been associated with greater use of screening. However, we do not know whether having an abnormal mammogram affects future screening. OBJECTIVE: To examine the effect of a false-positive mammogram on adherence to the next recommended screening mammogram. DESIGN: Prospective cohort study. SETTING: The breast cancer screening program at Group Health Cooperative, a health maintenance organization in Washington state. PATIENTS: 5059 women 40 years of age or older with no history of breast cancer or breast surgery who had false-positive (n = 813) or true-negative (n = 4246) index screening mammograms between 1 August 1990 and 31 July 1992. MEASUREMENTS: Screening rates and odds ratios for recommended interval screening up to 42 months after the index mammogram. RESULTS: After adjustment for differences in age; previous use of mammography; family history of breast cancer; exogenous hormone use; and age at menarche, first childbirth, and menopause, women with false-positive index mammograms were more likely than those with true-negative index mammograms to obtain their next recommended screening mammogram (odds ratio, 1.21 [95% CI, 1.01 to 1.45]). The relation between a false-positive mammogram and the likelihood of adherence to screening in the next recommended interval was strongest among women who had not previously undergone mammography (odds ratio, 1.66 [CI, 1.26 to 2.17]). CONCLUSIONS: Having a false-positive mammogram did not adversely affect screening behavior in the next recommended interval. Women with false-positive mammograms, especially those without previous mammography, were more likely to return for the next scheduled screening.

Breast symptoms among women enrolled in a health maintenance organization: frequency, evaluation, and outcome.

BACKGROUND: Few data exist about visits to primary care clinicians for breast symptoms in the United States. OBJECTIVE: To determine how often women present with breast symptoms, how these symptoms are evaluated, and how often cancer is diagnosed. DESIGN: Retrospective cohort study. SETTING: Staff-model division of a large health maintenance organization (HMO) in New England. PATIENTS: 2400 women who were 40 to 69 years of age as of 1 July 1983 and were continuously enrolled in the HMO until 30 June 1995. MEASUREMENTS: Information on all breast-related encounters from 1 July 1983 to 30 June 1993 was abstracted. Type of symptom, clinicians' findings and recommendations, and all subsequent evaluations were recorded. Cases of cancer diagnosed subsequent to the symptom were determined. RESULTS: Sixteen percent of the HMO population presented with a breast symptom during the 10-year period, for a rate of 22.8 presentations per 1000 person-years. Women younger than 50 years of age presented nearly twice as often as older women (P = 0.001). Women with breast symptoms had lower rates of screening than other women before presenting but higher rates of screening afterward (P < 0.001). Symptoms were evaluated beyond the initial visit in 66% of patients, and invasive procedures were performed in 27% of patients. Cancer was found in 6.2% of patients and 4.5% of episodes; rates of cancer detection varied significantly by type of symptom but not by patient age. CONCLUSIONS: Breast symptoms among women 40 to 70 years of age were common in this primary care practice. Evaluation beyond initial examinations was frequent, and invasive procedures were performed for 27% of patients. Cancer was diagnosed in more than 4% of episodes, indicating that follow-up of breast symptoms is important in primary care practices.

Self-referral for screening mammography.

Patients can obtain screening mammograms without a physician's referral, leading to potential problems in clinical care. Because of the complexity of self-referral and the limitations of prior studies, we examined this phenomenon in a representative sample of mammography facilities. A questionnaire was given to all women obtaining mammograms at nine Connecticut mammography facilities during a 2-week period. Facilities included mobile sites, urban fixed sites, and rural fixed sites. Responses were categorized according to whether or not the woman had seen a primary care provider within the last year and whether or not she had received a recommendation to obtain a mammogram. The response rate was 62% (732 of 1,189), and the mean age of respondents was 58 years (range, 30-100 years). Self-referred women, defined as those without a recent visit to a primary care clinician and without a clinician's recommendation for a mammogram, constituted 6% of respondents. Self-referred women were significantly more likely to use mobile facilities (78% vs 33%, p < .01) and be under 50 years of age (44% vs 28%, p = .02) compared with provider-referred women who had recently seen their provider. We conclude that younger women are obtaining screening mammograms without clear evidence of having seen their primary care provider in the previous year or having received a referral from their provider. Self-referral is especially common at mobile mammography facilities. Further study is needed to assess the clinical impact of self-referral on mass screening programs.

The efficacy of silver alloy-coated urinary catheters in preventing urinary tract infection: a meta-analysis.

PURPOSE: Indwelling urinary catheters are implicated in most cases of nosocomial urinary tract infection. Silver-coating of catheters may reduce the risk of these infections; however, trials have provided mixed results. We performed a meta-analysis to estimate the effectiveness of silver-coated urinary catheters. SUBJECTS AND METHODS: Published or unpublished articles were sought using MEDLINE, reference review, and correspondence with original authors, catheter manufacturers, and experts. Trials using silver-coated urinary catheters in the treatment group and uncoated urinary catheters in the control group were included. Bacteriuria, as evaluated by urine culture, was the outcome variable used to indicate urinary tract infection. Summary odds ratios (OR) and 95% confidence intervals (CI) were calculated using Mantel-Haenszel methods with a fixed-effects model. RESULTS: Of 117 reports retrieved, eight trials with a total of 2,355 patients satisfied inclusion criteria. The summary OR for urinary tract infection was 0.59 (95% CI, 0.42 to 0.84) indicating a significant benefit in the patients receiving silver-coated catheters. A test of heterogeneity, however, indicated that the odds ratios varied significantly among studies. Silver alloy catheters (OR = 0.24; 95% CI, 0.11 to 0.52) were significantly more protective against bacteriuria than silver oxide catheters (OR = 0.79; 95% CI, 0.56 to 1.10). CONCLUSIONS: This meta-analysis clarifies discrepant results among trials of silver-coated urinary catheters by revealing that silver alloy catheters are significantly more effective in preventing urinary tract infections than are silver oxide catheters. Though silver alloy urinary catheters cost about $6 more than standard urinary catheters, they may be worth the extra cost since catheter-related infection is a common cause of nosocomial infection and bacteremia.

Clinical predictors of Pneumocystis carinii pneumonia, bacterial pneumonia and tuberculosis in HIV-infected patients.

BACKGROUND: Clinicians are frequently faced with the differential diagnosis between Pneumocystis carinii pneumonia (PCP), bacterial pneumonia, and pulmonary tuberculosis in HIV-infected patients. OBJECTIVES: To identify features that could help differentiate these three pneumonia types at presentation by evaluating the clinical characteristics of the three diagnoses among patients at two urban teaching hospitals. DESIGN: Retrospective chart review. METHODS: Cases were HIV-infected patients with a verified hospital discharge diagnosis of PCP (n = 99), bacterial pneumonia (n = 94), or tuberculosis (n = 36). Admitting notes were reviewed in a standardized manner; univariate and multivariate analyses were used to determine clinical predictors of each diagnosis. RESULTS: Combinations of variables with the highest sensitivity, specificity, and odds ratios (OR) were as follows: for PCP, exertional dyspnea plus interstitial infiltrate (sensitivity 58%, specificity 92%; OR, 16.3); for bacterial pneumonia, lobar infiltrate plus fever < or = 7 days duration (sensitivity 48%, specificity 94%; OR, 14.6); and for tuberculosis, cough > 7 days plus night sweats (sensitivity 33%, specificity 86%; OR, 3.1). On regression analysis, independent predictors included interstitial infiltrate (OR, 10.2), exertional dyspnea (OR, 4.9), and oral thrush (OR, 2.9) for PCP; rhonchi on examination (OR, 12.4), a chart mention of 'toxic' appearance (OR, 9.1), fever < or = 7 days (OR, 6.6), and lobar infiltrate (OR, 5.8) for bacterial pneumonia; and cavitary infiltrate (OR, 21.1), fever > 7 days (OR, 3.9), and weight loss (OR, 3.6) for tuberculosis. CONCLUSIONS: Simple clinical variables, all readily available at the time of hospital admission, can help to differentiate these common pneumonia syndromes in HIV-infected patients. These findings can help to inform clinical decision-making regarding choice of therapy, use of invasive diagnostic procedures, and need for respiratory isolation.

Does diagnostic accuracy in mammography depend on radiologists' experience?

This study was designed to determine if radiologists' experience in mammography is associated with their performance in correctly interpreting mammograms. Study mammograms (n = 150) were chosen by stratified random sampling from those interpreted as normal, abnormal-benign or abnormal-suspicious for cancer, with oversampling of cancer cases. Ten radiologists who had varying amounts of experience were asked to read the mammograms. Associations between the levels of the radiologists' experience and their accuracy in reading mammograms were assessed. Significant associations (p < 0.05) were found between the frequency of immediate workup recommendations in cancer patients and obtaining feedback, total lifetime mammograms read, number of mammography continuing medical education (CME) credits, and practice type. Radiologists with more experience also noted smaller cancer lesions. However, these experience variables were also associated with increased workup recommendations in the noncancer patients (p < 0.10). In multivariable analysis, obtaining regular feedback and the total lifetime number of mammograms read were independently associate with the number of times immediate workup was recommended in the cancer cases. The most experienced radiologist had the highest sensitivity in diagnosing breast cancer. Further studies are needed to assess whether the current requirements of the U.S. Food and Drug Administration for radiologists who read mammograms ensure acceptable levels of accuracy.

Variation in mammographic breast density by time in menstrual cycle among women aged 40-49 years.

BACKGROUND: Mammography is less effective for women aged 40-49 years than for older women, which has led to a call for research to improve the performance of screening mammography for younger women. One factor that may influence the performance of mammography is breast density. Younger women have greater mammographic breast density on average, and increased breast density increases the likelihood of false-negative and false-positive mammograms. We investigated whether breast density varies according to time in a woman's menstrual cycle. METHODS: Premenopausal women aged 40-49 years who were not on exogenous hormones and who had a screening mammogram at a large health maintenance organization during 1996 were studied (n = 2591). Time in the menstrual cycle was based on the woman's self-reported last menstrual bleeding and usual cycle length. RESULTS: A smaller proportion of women had "extremely dense" breasts during the follicular phase of their menstrual cycle (24% for week 1 and 23% for week 2) than during the luteal phase (28% for both weeks 3 and 4) (two-sided P = .04 for the difference in breast density between the phases, adjusted for body mass index). The relationship was stronger for women whose body mass index was less than or equal to the median (two-sided P<.01), the group who have the greatest breast density. CONCLUSIONS/IMPLICATIONS: These findings are consistent with previous evidence suggesting that scheduling a woman's mammogram during the follicular phase (first and second week) of her menstrual cycle instead of during the luteal phase (third and fourth week) may improve the accuracy of mammography for premenopausal women in their forties. Breast tissue is less radiographically dense in the follicular phase than in the luteal phase.

Ten-year risk of false positive screening mammograms and clinical breast examinations.

BACKGROUND: The cumulative risk of a false positive result from a breast-cancer screening test is unknown. METHODS: We performed a 10-year retrospective cohort study of breast-cancer screening and diagnostic evaluations among 2400 women who were 40 to 69 years old at study entry. Mammograms or clinical breast examinations that were interpreted as indeterminate, aroused a suspicion of cancer, or prompted recommendations for additional workup in women in whom breast cancer was not diagnosed within the next year were considered to be false positive tests. RESULTS: A total of 9762 screening mammograms and 10,905 screening clinical breast examinations were performed, for a median of 4 mammograms and 5 clinical breast examinations per woman over the 10-year period. Of the women who were screened, 23.8 percent had at least one false positive mammogram, 13.4 percent had at least one false positive breast examination, and 31.7 percent had at least one false positive result for either test. The estimated cumulative risk of a false positive result was 49.1 percent (95 percent confidence interval, 40.3 to 64.1 percent) after 10 mammograms and 22.3 percent (95 percent confidence interval, 19.2 to 27.5 percent) after 10 clinical breast examinations. The false positive tests led to 870 outpatient appointments, 539 diagnostic mammograms, 186 ultrasound examinations, 188 biopsies, and 1 hospitalization. We estimate that among women who do not have breast cancer, 18.6 percent (95 percent confidence interval, 9.8 to 41.2 percent) will undergo a biopsy after 10 mammograms, and 6.2 percent (95 percent confidence interval, 3.7 to 11.2 percent) after 10 clinical breast examinations. For every 100 dollars spent for screening, an additional 33 dollars was spent to evaluate the false positive results. CONCLUSIONS: Over 10 years, one third of women screened had an abnormal test result that required additional evaluation, even though no breast cancer was present. Techniques are needed to decrease false positive results while maintaining high sensitivity. Physicians should educate women about the risk of a false positive result from a screening test for breast cancer.

Breast carcinoma tumor characteristics in black and white women.

BACKGROUND: A significant disparity in mortality rates exists between black and white patients with breast carcinoma. This study was designed to compare breast carcinoma tumor characteristics by race and to examine the possible reasons for these differences. METHODS: Female patients with an initial diagnosis of breast carcinoma between January 1, 1985 and December 31, 1993 were selected from the Yale-New Haven Hospital Tumor Registry for this retrospective cohort study. All black patients were eligible and white patients were selected randomly and matched to each black patient by year of diagnosis. Data were gathered from multiple sources including the hospital, the Connecticut Tumor Registry, and the U. S. Census. All pathology specimens were reviewed at Yale-New Haven Hospital. RESULTS: The final cohort had 100 black and 300 white patients. The black patients tended to be younger than white patients at the time of diagnosis (mean age 55 years vs. 60 years; P = 0.001). A significant racial difference was noted in eight tumor characteristics: stage, size of the tumor, lymph node status, presence of necrosis, vascular/lymphatic invasion, ductal carcinoma in situ, perineural invasion, and progesterone receptor status. Although income, medical insurance coverage, and method of tumor detection explained some pathology differences, black patients still were more likely to have necrosis and a larger tumor size, even after adjustment. CONCLUSIONS: Black patients with breast carcinoma tend to be diagnosed at a younger age and in a few important respects have different tumor characteristics compared with white patients, even after controlling for income, medical insurance coverage, and method of tumor detection after screening mammography. These differences may have etiologic and clinical implications.