American Medical Association Masterfile Research Articles

Surgeon Characteristics and Use of Breast Conservation Surgery in Women With Early Stage Breast Cancer

Most women with localized breast cancer have a choice between mastectomy and breast conserving surgery (BCS). Aside from clinical factors, this decision may be associated with surgeon and patient characteristics. We investigated the effect of surgeon characteristics on the BCS rate. We used the Surveillance, Epidemiology, and End Results-Medicare database to identify women >65 years, diagnosed with stages I-II BC, between 1991 and 2002, and used the Physician Unique Identification Number linked to the American Medical Association Masterfile to obtain information on surgeons. We investigated the association of patient demographic, tumor, and surgeon-related factors with receipt of BCS, using Generalized Estimating Equations to control for clustering. Of 56,768 women with breast cancer, 30,006 (53%) underwent BCS, whereas 26,762 (47%) underwent mastectomy. Between 1991 and 2002, the proportion of patients undergoing BCS increased from 35% to 60%. In a multivariate analysis, patients who received BCS were younger, of higher SES, and had more favorable tumor characteristics. They were also more likely to be black and live in metropolitan areas. Women who underwent BCS were more likely to have surgeons who were female (OR = 1.40; 95% CI: 1.25-1.55), US-trained (OR = 1.12; 95% CI: 1.02-1.22), with a larger patient panel (OR = 1.29; 95% CI: 1.21-1.39), and completed training after 1975 (OR = 1.16; 95% CI: 1.08-1.25), than surgeons of patients who underwent mastectomy. Surgeon characteristics, such as gender, training, year of graduation, and volume, are small but significant independent predictor of BCS. Efforts to differentiate whether these associations reflect patients' preferences, quality of physician training, surgeon attitudes, physician-patient communication, or other effects on decision-making are warranted.

Autonomy, religion and clinical decisions: findings from a national physician survey

Background:Patient autonomy has been promoted as the most important principle to guide difficult clinical decisions. To examine whether practising physicians indeed value patient autonomy above other considerations, physicians were asked...

Influence of private practice setting on adjuvant chemotherapy use for elderly women with early-stage breast cancer.

Abstract Abstract #5096 Background:
 For elderly women with breast cancer (BC), the decision to undergo treatment with adjuvant chemotherapy may be associated with non-medical factors, such as physician and practice characteristics. Since physicians influence medical decision-making, we evaluated the association between oncologist characteristics and receipt of adjuvant chemotherapy in elderly women at both high and low-risk for breast cancer recurrence.
 Methods:
 We used the SEER-Medicare database to identify women >65 years, diagnosed with stages I-III BC, between 1992-2002, and used the Physician Unique Identification Number linked to the American Medical Association Masterfile to obtain information on oncologists. We investigated the association of patient demographic, tumor, and oncologist-related factors with receipt of chemotherapy for both women with high and low risk of recurrence, using Generalized Estimating Equations to control for clustering. We defined patients as low-risk who had hormone sensitive, stage I/II cancer, and high-risk if they were hormone receptor negative and stage II/III.
 Results:
 Of 42,544 women with stage I-III BC, 8,714 (20%) were treated with adjuvant chemotherapy. The proportion of women with high-risk tumors treated was 61% while the proportion with low risk cancers was 15%. Patients who received chemotherapy were younger, of higher SES, and had less favorable tumor characteristics. They were also more likely to be married, diagnosed more recently and have fewer comorbid conditions. In a multivariable analysis, women who underwent chemotherapy were more likely be treated by an oncologists who was primarily employed in a private practice (OR=1.40; 95%CI 1.23-1.59), and completed training after 1975 (OR=1.12; 95%CI 1.01-1.26), and were less likely to have an oncologist who trained in the United States (OR=0.83; 95%CI 0.74-0.93), than oncologists of patients who did not receive chemotherapy. The association between oncologists in private practice and receipt of chemotherapy was slightly stronger for patients who were at high-risk (OR=1.55) than those for low-risk (OR=1.35) for cancer recurrence.
 Conclusions:
 After controlling for confounding variables, elderly women with both high risk and low risk BC treated by oncologists who were primarily employed in a private practice were more likely to receive adjuvant chemotherapy. Other oncologists characteristics, such as gender, patient volume and type of degree were not independent predictors of receipt of chemotherapy. Efforts to differentiate whether these associations reflect experience, practice setting, insurance type, or other economic incentives are warranted. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5096.

The geographic relationships between medical students' birth location and high school location

Differences in origins are important to understand because major data sources have different measures of origins. The most extensive source of data is the American Medical Association Masterfile and birth origins can be coded for 95% of United States allopathic medical students 1 . High school location data is nearly 100% available from medical school admission materials that are also collected nationally by medical education associations. The Masterfile is the best secondary source of career and location outcomes, but it does not include high school location data. Admission databases have no career or practice location data. Studies need to compare birth origin data with high school data to allow some understanding of the geographic differences present in the two background measures.

HIV Screening Among U.S. Physicians, 1999–2000

In 2006, the Centers for Disease Control and Prevention (CDC) put forth recommendations for routine HIV screening for all individuals aged 13-64. The frequency and correlates of HIV screening among U.S. physicians in 2000 were examined to provide baseline data for evaluating the implementation of the 2006 CDC HIV testing guidelines through a survey mailed to a random sample of U.S. physicians in the American Medical Association's Masterfile. The primary outcome was self-reported HIV screening of asymptomatic male and nonpregnant female patients. A total of 4133 (adjusted completion rate of 70.2%) returned a completed survey. Overall, 1133 (28.4%) of physicians reported HIV screening. U.S. physicians, who were female, black, Hispanic, practiced in a city of more than 250,000 people, diagnosed HIV in the past 2 years, or followed up with patients to see if they notified their sexual partners, were more likely to screen their patients for HIV. Emergency medicine, internal medicine, and pediatrics specialists were less likely to screen than family/general practitioners. In 2000, only a quarter of U.S. physicians reported screening their patients for HIV and these rates varied by physician characteristics and practice settings.

Medical Malpractice in Gastroenterology

Gastroenterologists commonly perceive themselves to be at increased legal risk because they perform invasive procedures. However, there is little published information about gastroenterology (GI) malpractice claims. The goal of this study was to evaluate available malpractice claim data within GI. This study was a database analysis of GI claims submitted by insurance companies to the Physician Insurers Association of America Data Sharing Project from January 1, 1985, to December 31, 2005. Another analysis from 2005 compared GI claims with other subspecialties. Sixty-six percent of physicians involved in claims had previous claims experience. The most common reasons for claims were errors in diagnosis (28%) and improper performance of a procedure (25%). Seventy-two percent of reported closed claims were settled out of court. Of 12,367 total claims in 2005, only 233 (1.8%) were within GI. GI ranked below other procedurally based subspecialties in numbers of claims per physician. GI does not rank highly among subspecialties in malpractice claims and only a minority of claims are procedure-related. Physicians with claims experience are likely to have further claims against them and should consider evaluating their practices.

The Contribution of International Medical Graduates to Diversity in the U.S. Physician Workforce: Graduate Medical Education

To describe the ethnicity/race and gender distribution of the international medical graduates (IMGs) qualified to enter graduate medical education (GME) and those who are actually in GME. The Educational Commission for Foreign Medical Graduates (ECFMG) database and the American Medical Association's Masterfile provided ethnicity/race and gender data for the pool of IMGs qualified to enter GME (ECFMG certificants from 2000-2005) and those in GME in 2005. Data for U.S. medical graduates come from Association of American Medical Colleges' publications. Compared with USMGs, both the pool of available IMGs and those in graduate training have a larger percentage of Asians and Hispanics, a lower percentage of Blacks and American Indian/Pacific Islanders, and a much lower percentage of Whites. The groups had comparable percentages of women. International medical graduates provide much-needed diversity in GME. Since most IMGs remain in the U.S. after training, this diversity can lead to a richer training environment, increased access to health care, and better health care outcomes.

Surgeon Characteristics and Receipt of Adjuvant Radiotherapy in Women With Breast Cancer

Adjuvant radiotherapy following breast conservation surgery (BCS) is considered to be an indicator of quality of care for the majority of women with breast cancer, but many women do not receive adjuvant radiotherapy. We investigated the association of surgeon-related factors with receipt of adjuvant radiotherapy after BCS. We used the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database to identify women aged 65 years or older with stage I/II breast cancer who were diagnosed between 1991 and 2002 and underwent BCS. We collected demographic and clinical data from SEER and treatment information from Medicare claims data. The American Medical Association Masterfile was used to obtain information on surgeons' characteristics, including sex, medical school location (United States or elsewhere), and type of degree (MD or Doctorate in Osteopathic Medicine [DO]). The associations of patient (age, race, rural vs urban residence, comorbidities, marital status), tumor (hormone receptor status, grade, stage), and surgeon-related factors with receipt of adjuvant radiotherapy were analyzed using Generalized Estimating Equations to control for clustering. All statistical tests were two-sided. Of 29,760 women in our sample, 22,207 (75%) received radiotherapy. Patients who received adjuvant radiotherapy were younger, had fewer comorbidities, and were more likely to be white, married, from an urban area, and diagnosed in a later year compared with those who did not. They were also more likely to have a surgeon who was female (79% vs 73%), had an MD degree (75% vs 68%), or was US trained (75% vs 70%). The multivariable analysis confirmed the association of radiotherapy with having a surgeon who was female (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.06 to 1.27), had an MD degree (OR = 1.55; 95% CI = 1.24 to 1.91), was US trained (OR = 1.12; 95% CI = 1.01 to 1.25), or had more than 15 patients (OR = 1.18; 95% CI = 1.10 to 1.28). Surgeon characteristics were associated with patients' receipt of adjuvant radiotherapy after BCS after controlling for patient and tumor characteristics, although the individual effect sizes were small for surgeon sex, location of training, and type of medical degree. More research is warranted to confirm the associations to determine whether they reflect surgeon behavior, patient response, or physician-patient interactions.

Impact of a Severe Influenza Vaccine Shortage on Primary Care Practice

Because of influenza vaccine shortages during the 2004-2005 influenza season, vaccine was targeted for high-risk priority groups. To assess among primary care physicians: (1) ability to identify priority patients; (2) extent of shortages; and (3) effects of shortages on vaccine redistribution, patient referral and future plans for vaccine delivery. Mailed surveys of pediatric (Peds), family medicine (FM), and general internal medicine (GIM) physicians randomly selected from the American Medical Association master file. Response rate was 37% and the study population included 377 Peds, 319 FM, and 251 GIM physicians. Seventy-five percent of Peds, 58% of FM and 60% of GIM had some method to identify priority patients, although only 39%, 21%, and 18%, respectively, had a computerized method. Forty-five percent of Peds, 73% of FM, and 75% of GIM experienced shortages, for a median of 2-3 months. Approximately 48%-50% of Peds, FM, and GIM obtained additional influenza doses; among these, 53% received vaccine from a public health entity. Fifty-one percent of Peds, 79% of FM, and 80% of GIM referred high-risk patients for immunization, 94% of the time to a public health clinic. More than 95% planned to administer influenza vaccine next season. The majority of physicians experienced influenza vaccine shortages for prioritized patients, especially those providers caring for adults. There was significant vaccine redistribution and patient referral, primarily involving the public health system. Enhancing methods of targeting priority patients and increasing cooperation with public health entities should be priorities in dealing with future influenza vaccine shortages.

Rural versus Non-Rural Differences in Surgeon Performed Endoscopy: Results of a National Survey

The ongoing decline in the number of general surgeons practicing in rural areas of the United States is concerning. Existing data show that rural surgeons perform a broad spectrum of cases including procedures that are not considered to be in the repertoire of most general surgeons. In particular, rural surgeons seem to be performing a sizeable number of endoscopic procedures. A sixty-item survey was mailed to 1700 rural surgeons while a random sample of 154 urban surgeons were telephoned and administered the same questionnaire. The general surgeons were identified using a list obtained from the American Medical Association Masterfile. The response rate was 25 per cent and 74 per cent among rural and nonrural surgeons respectively. Seventy four per cent of rural surgeons performed more than 50 flexible endoscopies a year in contrast to 33 per cent of nonrural surgeons (P < 0.05). Approximately 42 per cent of rural surgeons reported doing more than 200 procedures annually, whereas only 12 per cent of the nonrural surgeons did so. Additionally, 63 per cent of rural surgeons wished they had further training in endoscopy before starting practice as compared with 46 per cent (P < 0.05) of nonrural surgeons. Rural surgeons perform flexible endoscopy at a much higher rate than their nonrural counterparts. The majority of rural surgeons feel they would have benefited from additional flexible endoscopy training before entering practice.

Adding or Switching Antipsychotic Medications in Treatment-Refractory Schizophrenia

This study compared patients with schizophrenia whose antipsychotic medications were switched to manage treatment-resistant positive psychotic symptoms with those for whom another antipsychotic was added. Psychiatrists' characteristics and perceptions of effectiveness of the medication change on clinical outcomes were also reported. Psychiatrists participating in a nationally representative mailed survey (N=209) reported on the clinical features, management, and response to the change in antipsychotic medication (added versus switched) of one adult patient with treatment-refractory schizophrenia under their care for at least one year. Thirty-three percent of patients were treated with an added antipsychotic medication. Compared with patients whose antipsychotic medications were switched, those with an added antipsychotic medication were more likely to be female, to have received care from the same psychiatrist for more than two years, and to have been recently prescribed an antidepressant. Compared with psychiatrists who switched antipsychotic prescriptions, those who added an antipsychotic reported that the change was less likely to reduce positive symptoms, improve functioning, and prevent hospitalization. Psychiatrists who added rather than switched antipsychotics reported more frequent attendance at educational programs sponsored by a pharmaceutical company. Consistent with other lines of research and practice guideline recommendations, psychiatrists perceive antipsychotic polypharmacy to be a generally ineffective strategy for treatment-resistant positive psychotic symptoms. In light of these findings, efforts to identify and implement more effective evidence-based pharmacologic approaches should be undertaken.

Adding or Switching Antipsychotic Medications in Treatment-Refractory Schizophrenia

Adding or Switching Antipsychotic Medications in Treatment-Refractory Schizophrenia

Gender Differences in the Annual Income of Psychiatrists

Female physicians have traditionally earned less than their male counterparts, even after adjustment for specialty, workload, and physician characteristics. In the 1980s female psychiatrists earned incomes that were 13% lower than those of their male counterparts; however, important explanatory variables for such differences were not incorporated into that analysis. This study examined whether a gender income gap among psychiatrists persisted in the 1990s. Survey responses were used that were obtained between 1992 and 2001 from 976 actively practicing white psychiatrists (weighted N=941). Because of low numbers of black respondents to the surveys, we were unable to examine the influence of race on psychiatrists' incomes. Linear regression modeling was performed to determine the association between gender and annual incomes after controlling for workload, provider characteristics, and practice characteristics. Among white psychiatrists, women reported working 13% fewer annual hours than their male counterparts, and women had practiced medicine for fewer years than men. Also, women were more likely to be employees of the practice, as opposed to having an ownership interest in the practice, and were more likely to be board certified, although these findings were not significant. After adjustment for workload, provider characteristics, and practice characteristics, the mean annual income for women was $140,615, or $31,962 (19%) lower than that of men (95% confidence interval of $41,834-$22,090 lower, p<.001). During the 1990s female gender was associated with lower annual incomes among white psychiatrists; compared with previous reports from earlier periods the income disparity appears to be widening. These findings warrant further exploration.

Gender Differences in the Annual Income of Psychiatrists

Gender Differences in the Annual Income of Psychiatrists

Who Will Do the Work? What Work Will They Do?

in the United States. 2 This first-pass determination was done during a time when the expense of oncology care was starting to become an issue, in an era of more rudimentary cancer treatments, and on a background of proposals to reduce oncologytraining slots by 40%. The then-estimated 3,600 full-time-equivalent oncologists were adequate, based on comparisons with staff model health maintenance organizations’ (HMOs) use of oncologists per 100,000 population. Though this estimate of the workforce size was almost certainly wrong, the earlier study’s two main conclusions are largely true: oncologists desired delivering less primary care, and the workforce was right-sized. Fifteen years on, most oncologists are as busy as they want to be, and they spend their professional time delivering specialty oncology care. The current study used many data sources (both existing and new data from four surveys) to provide a more reliable estimate of the current oncology workforce—the American Medical Association Masterfile of physicians—and a more robust estimate of the potential patient population and oncology practice patterns. The results indicate that we will be facing a shortage of 2,550 to 4,080 oncologists by 2020 —which could translate to 9.4 to 15 million fewer oncologist visits. The study used a combination of Medicare visit data and National Cancer Institute incidence and prevalence projections to determine the demand for services and capacity of the workforce to deliver those services. The authors performed sensitivity analyses, testing the effects of increasing oncology training slots, electronic medical record use, and midlevel provider use on visit capacity and workforce supply. Projections were also made on the effects of delaying retirement of current oncologists and potential for decreased work hours and thus productivity in younger oncologists. The model’s sensitivity to increases in the number of new cancer patients seen by an oncologist, to varying the intensity of oncologist interaction with each patient, and to truncation of oncologist interaction with each patient by use of hospice or primary care providers to manage various stages of the illness was tested. Making predictions, especially about the future, is difficult, as was observed by both the theoretical physicist Niels Bohr and the applied physicist Yogi Berra. The wildest swings in the predictive model for visit demand (Table 4) occur when the proportion of new cancer cases seen by an oncologist is varied. 1 Many other specialists manage early-stage colon, skin, and prostate cancers. Medical oncologists add little value to management of these early-stage tumors, but radical changes in the management of these conditions (effective adjuvant systemic therapy for early-stage, high-risk prostate and colon cancers for instance) could radically alter the demand forecast. On the contrary, simplification in the management of hormone receptor–positive early-stage breast cancer could lead to more management of this now-common condition by surgeons or other nononcologists. It is difficult to predict the changes in practice patterns that biomedical or information technology will bring 15 years from now. Market forces should be allowed to continue to guide adjustments of oncology care. The reason medical oncologists see less early-stage prostate and skin cancer is that we currently add little value to the care of these patients. As oncologists become relatively rarer and our time more dear, we will figure out ways to become more productive diagnosticians, innovators, and problem solvers. We will spend less professional time performing extensive documentation and other non–value-added tasks, and more time developing and leading our teams. We should develop and refine guideline-based care so that we can delegate more routine tasks to midlevel providers, experienced oncology nurses, and others who specialize in managing various aspects of the cancer care continuum. Information technology should be developed to allow us to spend more productive time with our patients. Those new associates who are identified and hired should add value to patient care and only do work for which a trained medical oncologist is required.

Future supply and demand for oncologists : challenges to assuring access to oncology services.

To conduct a comprehensive analysis of supply of and demand for oncology services through 2020. This study was commissioned by the Board of Directors of ASCO. New data on physician supply gathered from surveys of practicing oncologists, oncology fellows, and fellowship program directors were analyzed, along with 2005 American Medical Association Masterfile data on practicing medical oncologists, hematologists/oncologists, and gynecologic oncologists, to determine the baseline capacity and to forecast visit capacity through 2020. Demand for visits was calculated by applying age-, sex-, and time-from-diagnosis-visit rate data from the National Cancer Institute's analysis of the 1998 to 2002 Surveillance, Epidemiology and End Results (SEER) database to the National Cancer Institute's cancer incidence and prevalence projections. The cancer incidence and prevalence projections were calculated by applying a 3-year average (2000-2002) of age- and sex-specific cancer rates from SEER to the US Census Bureau population projections released on March 2004. The baseline supply and demand forecasts assume no change in cancer care delivery and physician practice patterns. Alternate scenarios were constructed by changing assumptions in the baseline models. Demand for oncology services is expected to rise rapidly, driven by the aging and growth of the population and improvements in cancer survival rates, at the same time the oncology workforce is aging and retiring in increasing numbers. Demand is expected to rise 48% between 2005 and 2020. The supply of services provided by oncologists during this time is expected to grow more slowly, approximately 14%, based on the current age distribution and practice patterns of oncologists and the number of oncology fellowship positions. This translates into a shortage of 9.4 to 15.0 million visits, or 2,550 to 4,080 oncologists-roughly one-quarter to one-third of the 2005 supply. The baseline projections do not include any alterations based on changes in practice patterns, service use, or cancer treatments. Various alternate scenarios were also developed to show how supply and demand might change under different assumptions. ASCO, policy makers, and the public have major challenges ahead of them to forestall likely shortages in the capacity to meet future demand for oncology services. A multifaceted strategy will be needed to ensure that Americans have access to oncology services in 2020, as no single action will fill the likely gap between supply and demand. Among the options to consider are increasing the number of oncology fellowship positions, increasing use of nonphysician clinicians, increasing the role of primary care physicians in the care of patients in remission, and redesigning service delivery.

Educational Commission for Foreign Medical Graduates Certification and Specialty Board Certification Among Graduates of the Caribbean Medical Schools

To determine the variability among Caribbean medical schools in the performance of their students against markers of quality. The Educational Commission for Foreign Medical Graduates (ECFMG) database and the American Medical Association (AMA) Masterfile were linked. Analyses were restricted to ECFMG applicants, from 1980 to 2000, who attended the 12 Caribbean medical schools that produced 200 or more U.S. International Medical School Graduates (USIMGs). The schools produced 17,049 USIMG (48% of all USIMGs) and 5,840 non-USIMG (5% of all non-USIMGs) applicants for ECFMG certification. By school, the ECFMG certification rate ranged from 28% to 86% for USIMGs and from 27% to 82% for non-USIMGs. Specialty Board certification for graduates of these schools also varied widely. Medical schools in the Caribbean play an increasingly important role in supplying the U.S. workforce. There is considerable variability among them, both in the numbers of physicians they produce and the performance of their students against indicators of quality such as ECFMG and specialty Board certification.

Universal Health Care and Reform of the Health Care System: Views of Medical Students in the United States

Nearly 46 million Americans did not have health insurance in 2004. Recent studies have documented physicians' support for various remedies, including universal health care. The authors undertook this study to assess medical students' views on these topics. In 2002, the authors surveyed a national random sample of first-year and fourth-year medical students (from the American Medical Association Masterfile) to determine their views about health care reform options, including universal health care. Response data were weighted and compared using chi-squared tests; statistical significance was set at p < or = .05. Of 1,363 medical students, 770 completed the questionnaire (response rate = 56.5%). In rating the importance of several health care issues, more than 80% of both first-year and fourth-year students rated the expansion of health care coverage as important. Nearly all first-year (90%) and fourth-year (88%) students agreed with the statement, "Everyone is entitled to adequate medical care regardless of ability to pay." Most students favored health care reform that would achieve universal health care, with first-year students (70%) somewhat more likely than fourth-year students (61%) to support universal health care (p = .012). Students were less likely to believe that physicians support universal health care, and more likely to believe that the public does. Both groups of students generally support the expansion of health coverage to the uninsured and some form of universal health care. This may be relevant both to policymakers in their considerations of health care reform and to medical educators concerned with teaching students about health policy issues.

Use of a New Combined Vaccine in Pediatric Practices

On December 13, 2002, Pediarix, a combination vaccine that contains diphtheria, tetanus, acellular pertussis; hepatitis B; and inactivated polio vaccines, was licensed by the Food and Drug Administration for use in the primary immunization series. Use of this vaccine decreases the number of injections that children receive when completing their primary immunization series at the 2-, 4-, and 6-month well-child visits. The objective of this study was to determine the factors that influence the use of this combined vaccine in private pediatric practices, with particular attention to the perceived economic impact of Pediarix and actions taken to address this impact within the private pediatric setting. A mail survey study was conducted of a random sample of 565 practicing pediatricians that was obtained from the American Medical Association Masterfile. Frequency distributions were developed for all responses, and the vaccine financing policies of the state of practice for each respondent were determined. Chi2 analysis was performed to assess any associations of the predictor variables with the outcome variables of interest, use or consideration of use of the Pediarix vaccine. Logistic regression was used to determine the independent association of the predictor variables with use or consideration of use of Pediarix. Regression models that did and did not include practice ownership as a predictor variable were developed. Response rate was 63% (N = 355). A total of 39% (n = 123) of the respondents' practices were purchasing Pediarix for use with their private patients. An additional 18% (n = 55) were considering purchasing the vaccine. Those who were in practices that were owned by hospitals or health systems were more likely than those who were in solo or group practices to purchase Pediarix for their private patients. Approximately half of the remaining respondents order Pediarix through their state immunization program. Among the 52% of respondents who did not, 23% reported that the vaccine was not yet available through their state program, and 47% stated that they did not want to use different vaccines for their public and private patients. Only 11% believed that Pediarix was not compatible with their other vaccine products. Physicians that currently were purchasing or considering purchasing Pediarix were more likely to be influenced by both parental and provider desire to decrease the number of injections at a single visit and the reduced time for immunization delivery. Fewer than 1% of respondents reported either having experienced or expecting to experience a significant decrease in practice revenue as a result of the use of Pediarix. Although use of the vaccine results in fewer administration fees for most physicians, the magnitude of the change seemed not to be significant for the majority of respondents or was outweighed by other factors. It also is possible that larger practices or buying cooperatives were able to negotiate discounted rates for Pediarix relative to the constituent products. This may have been a strategy of manufacturers and/or distributors to provide incentive for practices to switch to the combination product. Of note was the appreciation of respondents for the preferences of patients for fewer vaccines and, to a lesser degree, for the decrease in office staff time required to provide vaccination with multiple antigens when using Pediarix. Also, the role of the availability of a given vaccine through the Vaccines for Children program is important in its adoption into practice.

Variation in false-positive rates of mammography reading among 1067 radiologists: a population-based assessment

The accuracy of mammography reading varies among radiologists. We conducted a population-based assessment on radiologist variation in false- positive rates of screening mammography and its associated radiologist characteristics. About 27,394 screening mammograms interpreted by 1067 radiologists were identified from a 5% non-cancer sample of Medicare claims during 1998-1999. The data were linked to the American Medical Association Masterfile to obtain radiologist characteristics. Multilevel logistic regression models were used to examine the radiologist variation in false-positive rates of screening mammography and the associated radiologist characteristics. Radiologists varied substantially in the false-positive rates of screening mammography (ranging from 1.5 to 24.1%, adjusting for patient characteristics). A longer time period since graduation is associated with lower false-positive rates (odds ratio [OR] for every 10 years increase: 0.87, 95% Confidence Interval [CI], 0.81-0.94) and female radiologists had higher false-positive rates than male radiologists (OR = 1.25, 95% CI, 1.05-1.49), adjusting for patient and other radiologist characteristics. The unmeasured factors contributed to about 90% of the between-radiologist variance. Radiologists varied greatly in accuracy of mammography reading. Female and more recently trained radiologists had higher false-positive rates. The variation among radiologists was largely due to unmeasured factors, especially unmeasured radiologist factors. If our results are confirmed in further studies, they suggest that system-level interventions would be required to reduce variation in mammography interpretation.