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Shavers VL, Brown ML, Potosky AL, Klabunde CN, Davis WW, Moul JW, Fahey A. Race/ethnicity and the receipt of watchful waiting for the initial management of prostate cancer. J Gen Intern Med 2004; 19:146-55. [PMID: 15009794 PMCID: PMC1492143 DOI: 10.1111/j.1525-1497.2004.30209.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Several recent studies have noted that African Americans disproportionately receive "watchful waiting" for the initial management of their prostate cancer. To determine whether racial/ethnic differences in the receipt of watchful waiting are explained by differences in clinical presentation and life expectancy at the time of diagnosis, we examined Surveillance, Epidemiology, and End Results (SEER)-Medicare data for men diagnosed with prostate cancer in 1994 to 1996. METHODS Race/ethnicity, comorbidity, stage, grade, age, and expected lifespan and their association with the receipt of watchful waiting were examined in multivariate logistic regression analyses. Race-stratified logistic regression analyses were also used to examine racial/ethnic variation in the association of clinical and demographic factors with the receipt of watchful waiting among African-American, Hispanic, and non-Hispanic white men. RESULTS African-American (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.3 to 1.6) and Hispanic men (OR, 1.3; 95% CI, 1.1 to 1.5) were significantly more likely than non-Hispanic white men to receive watchful waiting in a multivariate model adjusted for age, comorbidity, stage, grade, and life expectancy. Advanced stage and grade, lower life expectancy, older age, and high comorbidity indices were also significantly associated with an increase in the odds of receipt of watchful waiting in multivariate analyses. In general, the association between the receipt of watchful waiting and the clinical characteristics (i.e., stage, grade, and age) were similar for the three racial/ethnic groups. In race-stratified logistic regression analyses, life expectancy was associated with an increase in the odds of receiving watchful waiting but results were statistically significant for whites only. There was also a statistically significant increase in the odds of receiving watchful waiting for African-American and white men with high comorbidity indices but not Hispanic men. The odds of receiving watchful waiting were also higher for African-American and Hispanic men who resided in census tracts where a large percentage of residents had not completed high school than for white men who resided in similar census tracts. CONCLUSION The disproportionate receipt of watchful waiting among African Americans and Hispanics is not completely explained by racial/ethnic variation in clinical characteristics or life expectancy as measured in this study. These data suggest that there are other factors that contribute to racial/ethnic differences in receipt of watchful waiting that warrant investigation.
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Sansbury LB, Klabunde CN, Mysliwiec P, Brown ML. Physicians' use of nonphysician healthcare providers for colorectal cancer screening. Am J Prev Med 2003; 25:179-86. [PMID: 14507523 DOI: 10.1016/s0749-3797(03)00203-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Data on the involvement of nonphysician healthcare providers in colorectal cancer (CRC) screening delivery are sparse. This article describes physicians' use of nurse practitioners and physician assistants to provide CRC screening with the fecal occult blood test (FOBT), flexible sigmoidoscopy, and colonoscopy, as well as physicians' attitudes toward using these providers to perform flexible sigmoidoscopy. METHODS Nationally representative samples of primary care physicians, gastroenterologists, and general surgeons were surveyed in 1999-2000. Descriptive statistics and logistic regression were used to estimate the prevalence and predictors of physicians' use of nurse practitioners and physician assistants for CRC screening and to assess physicians' attitudes toward their use in providing CRC screening with flexible sigmoidoscopy. RESULTS Overall, 24% of primary care physicians reported using a nurse practitioner or physician assistant to provide CRC screening with FOBT. However, only 3% of all physicians surveyed used nurse practitioners and physician assistants for CRC screening with flexible sigmoidoscopy, and less than 1% of gastroenterologists and general surgeons reported using these providers to perform CRC screening with colonoscopy. Approximately 15% of general surgeons, 40% of primary care physicians, and 60% of gastroenterologists who do not currently use nurse practitioners or physician assistants to perform CRC screening with flexible sigmoidoscopy agreed that these providers could effectively perform the procedure. CONCLUSIONS These results show current involvement of nurse practitioners and physician assistants in the delivery of CRC screening to be limited. Use of nonphysician healthcare providers for CRC screening with FOBT and flexible sigmoidoscopy is one possible solution to the challenge of boosting low screening rates. However, physician beliefs about the ability of nurse practitioners and physician assistants to perform flexible sigmoidoscopy are a potential barrier to increasing the involvement of nonphysician providers in CRC screening delivery.
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Brown ML, Klabunde CN, Mysliwiec P. Current capacity for endoscopic colorectal cancer screening in the United States: data from the National Cancer Institute Survey of Colorectal Cancer Screening Practices. Am J Med 2003; 115:129-33. [PMID: 12893399 DOI: 10.1016/s0002-9343(03)00297-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE There is a national goal in the United States to increase the level of colorectal cancer screening, but there is currently little information on resources for the delivery of endoscopic screening and follow-up diagnostic and surveillance procedures. The purpose of this study was to provide nationally representative data on endoscopic resources at the provider level. METHODS A nationally representative survey of primary care physicians, general surgeons, and gastroenterologists that was conducted during 1999 to 2000 provided data from survey responses by 1235 primary care physicians, 349 gastroenterologists, and 316 general surgeons. RESULTS We estimated that 65% of all sigmoidoscopy procedures were performed by primary care physicians, 25% by gastroenterologists, and 10% by general surgeons. Only 30% of all primary care physicians performed any procedures, and average volume among those who did was relatively low (seven per month). Gastroenterologists performed two thirds of all colonoscopy procedures, with most of the remainder performed by general surgeons. CONCLUSION There is potential to increase the capacity to perform screening sigmoidoscopy procedures through primary care delivery. However, without careful consideration of organizational factors, this could result in increased cost and quality control problems. Increasing the capacity for screening colonoscopy is feasible, but will require attention to other problems, such as avoiding overfrequent (e.g., annual or biennial) procedures in low-risk patients.
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Klabunde CN, Jones E, Brown ML, Davis WW. Colorectal cancer screening with double-contrast barium enema: a national survey of diagnostic radiologists. AJR Am J Roentgenol 2002; 179:1419-27. [PMID: 12438029 DOI: 10.2214/ajr.179.6.1791419] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This article describes diagnostic radiologists' colorectal cancer screening activities and beliefs about screening effectiveness and future capacity for screening with double-contrast barium enema, and compares radiologists' opinions about colorectal cancer screening with those of primary care physicians. MATERIALS AND METHODS We surveyed a nationally representative sample of diagnostic radiologists. Of 381 eligible radiologists, 312 (82%) responded. Descriptive statistics and chi-square tests were used to assess radiologists' opinions about double-contrast barium enema volume and capacity and to compare radiologists' beliefs about colorectal cancer screening with those of primary care physicians. Logistic regression was used to identify characteristics of radiologists who receive referrals for or perform a higher volume of screening double-contrast barium enema and of those who expect the volume of double-contrast barium enemas to increase. RESULTS Seventy-five percent of radiologists said that double-contrast barium enema is a "very effective" colorectal cancer screening procedure compared with 33% of primary care physicians. Although 86% of radiologists reported performing one or more screening double-contrast barium enema procedures during a typical month, only 27% indicated that they did so 11 or more times. Fifteen percent of radiologists said that their double-contrast barium enema volume had increased over the past 3 years, and 50% expect an increase over the next 3 years. Only 8% said that the capacity of facilities and personnel to meet the demand for double-contrast barium enemas in their geographic area of practice is inadequate. Geographic region and belief in double-contrast barium enema efficacy were predictors of double-contrast barium enema volume and referrals. CONCLUSION Most diagnostic radiologists perform colorectal cancer screening with double-contrast barium enema, but procedure volumes are modest. Because primary care physicians view double-contrast barium enema less positively than do radiologists, radiologists' expectations for an increased volume of double-contrast barium enemas over the next few years may not be realized.
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Ellison GL, Brown ML, Warren JL, Knopf KB. #69 Racial and ethnic differences in bowel surveillance procedures following colorectal cancer surgery with curative intent. Ann Epidemiol 2002. [DOI: 10.1016/s1047-2797(02)00357-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Brown ML, Riley GF, Schussler N, Etzioni R. Estimating health care costs related to cancer treatment from SEER-Medicare data. Med Care 2002; 40:IV-104-17. [PMID: 12187175 DOI: 10.1097/00005650-200208001-00014] [Citation(s) in RCA: 254] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cancer-specific medical care costs are used by health service researchers, medical decision analysts, and health care policymakers. The SEER-Medicare database is a unique data resource that makes it possible to derive incidence- and prevalence-based estimates of cancer-related medical care costs by site and stage of disease, by treatment approach, and for age and gender strata for individuals older than 65 years. OBJECTIVES This paper describes the cost-related data available in the SEER-Medicare database, and discusses techniques and methods that have been used to derive various cost estimates from these data. The limitations of SEER-Medicare data as a source of cost estimates are also discussed. RESULTS Examples of cost estimates for colorectal and breast cancer derived from SEER-Medicare are presented, including estimates of incidence-based cost (average cost per patient) by the initial, terminal, and continuing care phases of cancer treatment. Estimates of cancer-related treatment costs, costs by type of treatment, and long-term costs are presented, as are prevalence-based costs (aggregate Medicare and national expenditures) by cancer type.
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Field TS, Cadoret CA, Brown ML, Ford M, Greene SM, Hill D, Hornbrook MC, Meenan RT, White MJ, Zapka JM. Surveying physicians: do components of the "Total Design Approach" to optimizing survey response rates apply to physicians? Med Care 2002; 40:596-605. [PMID: 12142775 DOI: 10.1097/00005650-200207000-00006] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Surveys serve essential roles in clinical epidemiology and health services research. However, physician surveys frequently encounter problems achieving adequate response rates. Research on enhancing response rates to surveys of the general public has led to the development of Dillman's "Total Design Approach" to the design and conduct of surveys. The impact of this approach on response rates among physicians is uncertain. OBJECTIVE To determine the extent to which the components of the total design approach have been found to be effective in physician surveys. DESIGN A systematic review. RESULTS The effectiveness of prepaid financial incentives, special contacts, and personalization to enhance response rates in surveys of physicians have been confirmed by the existing research. There is suggestive evidence supporting the use of first class stamps on return envelopes and multiple contacts. The optimum amount for incentives and the number of contacts necessary have not been established. Details of questionnaire design and their impact on response rates have received almost no attention from researchers. Few studies have assessed the usefulness of combinations of components of the total design approach. CONCLUSIONS Despite the number of surveys conducted among physicians, their cost, the level of interest in their findings, and in spite of inadequate response rates, there have been few randomized trials conducted on important aspects of enhancing response in this population. Until this gap has been filled, researchers conducting surveys of physicians should consider including all components of the total design approach whenever feasible.
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Abstract
A disproportionate number of cancer deaths occur among racial/ethnic minorities, particularly African Americans, who have a 33% higher risk of dying of cancer than whites. Although differences in incidence and stage of disease at diagnosis may contribute to racial disparities in mortality, evidence of racial disparities in the receipt of treatment of other chronic diseases raises questions about the possible role of inequities in the receipt of cancer treatment. To evaluate racial/ethnic disparities in the receipt of cancer treatment, we examined the published literature that addressed access/use of specific cancer treatment procedures, trends in patterns of use, or survival studies. We found evidence of racial disparities in receipt of definitive primary therapy, conservative therapy, and adjuvant therapy. These treatment differences could not be completely explained by racial/ethnic variation in clinically relevant factors. In many studies, these treatment differences were associated with an adverse impact on the health outcomes of racial/ethnic minorities, including more frequent recurrence, shorter disease-free survival, and higher mortality. Reducing the influence of nonclinical factors on the receipt of cancer treatment may, therefore, provide an important means of reducing racial/ethnic disparities in health. New data resources and improved study methodology are needed to better identify and quantify the full spectrum of nonclinical factors that contribute to the higher cancer mortality among racial/ethnic minorities and to develop strategies to facilitate receipt of appropriate cancer care for all patients.
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Warren JL, Brown ML. Chemotherapy in the elderly. N Engl J Med 2002; 346:622-3. [PMID: 11858266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Warren JL, Brown ML, Fay MP, Schussler N, Potosky AL, Riley GF. Costs of treatment for elderly women with early-stage breast cancer in fee-for-service settings. J Clin Oncol 2002; 20:307-16. [PMID: 11773184 DOI: 10.1200/jco.2002.20.1.307] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE This study provides population-based estimates of the treatment costs for elderly women with early-stage breast cancer, with emphasis on costs of modified radical mastectomy (MRM) compared with breast-conserving surgery (BCS) and radiation therapy (RT). PATIENTS AND METHODS Women with breast cancer from the Surveillance, Epidemiology, and End Results cancer registries were linked with their Medicare claims, 1990 through 1998. Each claim was assigned to an initial, continuing, or terminal care phase after a cancer diagnosis. Mean monthly phase-specific costs were determined for all health care and for treatment related only to cancer. Cumulative long-term costs of care that accrue during a women's remaining lifetime were calculated by treatment group. RESULTS Initial care costs for the 6 months after diagnosis for women who underwent BCS with RT were approximately $450 per month higher than for women with MRM. During the continuing-care phase, costs for women undergoing BCS with RT were significantly less expensive than for MRM cases. The two groups had similar costs in the terminal-care phase. Assuming the same survival distributions, long-term costs for women undergoing BCS with RT were not statistically different than for women undergoing MRM. CONCLUSION Although mastectomy was less costly in the initial phase, the lifetime costs of BCS with RT and mastectomy were equivalent. Thus, women's preferences, resources to cover out-of-pocket costs, and life situations should be the major factors addressed in shared decision making about treatment options.
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Breen N, Wagener DK, Brown ML, Davis WW, Ballard-Barbash R. Progress in cancer screening over a decade: results of cancer screening from the 1987, 1992, and 1998 National Health Interview Surveys. J Natl Cancer Inst 2001; 93:1704-13. [PMID: 11717331 DOI: 10.1093/jnci/93.22.1704] [Citation(s) in RCA: 381] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Screening to detect cancer early, an increasingly important cancer control activity, cannot be effective unless it is widely used. METHODS Use of Pap smears, mammography, fecal occult blood tests (FOBTs), sigmoidoscopy, and digital rectal examination (DRE) was evaluated in the 1987, 1992, and 1998 National Health Interview Surveys. Levels and trends in screening use were examined by sex, age, and racial/ethnic group. The effects of income, educational level, and health care coverage were examined within age groups. Logistic regression analyses of 1998 data were used to develop a parsimonious, policy-relevant model. RESULTS Use of all screening modalities increased over the period examined; for mammography and DRE, the increase was more rapid in the first half of the decade; for the Pap test and sigmoidoscopy, the increase was more rapid in the second half of the decade. Levels of colorectal cancer screening (both sigmoidoscopy and FOBTs) in 1998 were less than the level that prevailed a decade earlier for mammography. Patterns of change for all screening modalities differed between age, sex, and racial/ethnic groups, but prevalence of use during the study, within recommended time intervals, was consistently lower among groups with lower income and less education. Logistic regression analyses indicated that insurance coverage and, to a greater extent, usual source of care had strong independent associations with screening usage when age, sex, racial/ethnic group, and educational level were taken into account. CONCLUSIONS While cancer screening is generally increasing in the United States, usage is relatively low for colorectal cancer screening and among groups that lack health insurance or a usual source of care.
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Knopf KB, Warren JL, Feuer EJ, Brown ML. Bowel surveillance patterns after a diagnosis of colorectal cancer in Medicare beneficiaries. Gastrointest Endosc 2001; 54:563-71. [PMID: 11677471 DOI: 10.1067/mge.2001.118949] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND Postoperative colon surveillance has been recommended for patients with a diagnosis of local/regional colorectal cancer. The extent to which these recommendations are followed in practice is poorly characterized. Patterns of surveillance after surgery for colorectal cancer were determined by using a large population-based database. METHODS This is a retrospective cohort study with cancer registry data linked to Medicare claims. Identified were 52,283 patients treated for local/regional colorectal cancer between 1986 and 1996, and surveillance patterns through 1998 were determined. Surveillance patterns were analyzed by using survival analysis and by computing the proportion of surviving patients who underwent procedures during 4 time periods after treatment: 2 to 14 months, 15 to 50 months, 51 to 86 months and more than 87 months. RESULTS Median times to first through fifth surveillance events were 20, 14, 15, 15, and 15 months, respectively. For 17% of the cohort there was no surveillance event. Younger patients were more likely to undergo surveillance. Surveillance patterns were not affected by stage. The proportions of the cohort that underwent no surveillance during the 4 respective time periods were 54%, 52%, 60%, and 69%. The percentages of patients who underwent surveillance annually or more frequently in the latter 3 time periods, respectively, were 19%, 10%, and 5%, or 11% overall, treating the data for the 3 events as a whole. Over the period from 1986 to 1998, the proportion of patients who had no surveillance procedures gradually decreased, whereas the proportion of those who underwent procedures annually or more frequently remained relatively constant. CONCLUSIONS During the period from 1986 to 1998 there was low utilization of postdiagnosis colon surveillance in a substantial proportion of elderly patients with a diagnosis of local/regional colorectal cancer. Over time there was a trend toward increasing receipt of any surveillance procedures. The percentages of patients undergoing surveillance annually or more frequently did not change between earlier and later periods.
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Brown ML. The effects of environmental tobacco smoke on children: Information and implications for PNPs. J Pediatr Health Care 2001; 15:280-6. [PMID: 11717683 DOI: 10.1067/mph.2001.116492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although much information is available about the harmful effects of smoking and exposure to environmental tobacco smoke (ETS), many children are in contact with ETS in their home every day. Health effects related to ETS vary from minor nasal irritation to an increased susceptibility to sudden infant death syndrome. ETS can also cause future health problems as exposed children become adults. Assessment of ETS exposure is an essential component of a patient's health history, and parents should be educated about the harmful effects of ETS and how to protect young children from it. Strategies for prevention of ETS exposure must be pursued to ensure improved health outcomes for all children.
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Frick GF, Reveal JL, Broome CR, Brown ML. The practice of Dr. Andrew Scott of Maryland and North Carolina. MARYLAND HISTORICAL MAGAZINE 2001; 82:123-41. [PMID: 11617667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Frick GF, Reveal JL, Broome CR, Brown ML. Botanical explorations and discoveries in colonial Maryland, 1688 to 1753. HUNTIA; A YEARBOOK OF BOTANICAL AND HORTICULTURAL BIBLIOGRAPHY 2001; 7:5-59. [PMID: 11612125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Broome CR, Frick GF, Brown ML, Reveal JL. A 1698 Maryland florula by the London apothecary James Petiver (ca. 1663-1718). HUNTIA; A YEARBOOK OF BOTANICAL AND HORTICULTURAL BIBLIOGRAPHY 2001; 7:61-90. [PMID: 11612126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Brown ML, Lipscomb J, Snyder C. The burden of illness of cancer: economic cost and quality of life. Annu Rev Public Health 2001; 22:91-113. [PMID: 11274513 DOI: 10.1146/annurev.publhealth.22.1.91] [Citation(s) in RCA: 221] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cancer is a major public health issue and represents a significant burden of disease. In this chapter, we analyze the main measures of burden of disease as relate to cancer. Specifically, we review incidence and mortality, years of life lost from cancer, and cancer prevalence. We also discuss the economic burden of cancer, including cost of illness, phase-specific and long-term costs, and indirect costs. We then examine the impact of cancer on health-related quality of life as measured in global terms (disability-adjusted life years and quality-adjusted life years) and using evaluation-oriented applications of health-related quality of life scales. Throughout, we note the relative strengths and weaknesses of the various approaches to measuring the burden of cancer as well as the methodologic challenges that persist in burden-of-illness research. We conclude with a discussion of the research agenda to improve our understanding of the burden of cancer and of illness more generally.
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Lee PC, Mateo RB, Clarke MR, Brown ML, Carty SE. Parathyromatosis: a cause for recurrent hyperparathyroidism. Endocr Pract 2001; 7:189-92. [PMID: 11421566 DOI: 10.4158/ep.7.3.189] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To report a case of parathyromatosis as a cause for recurrent hyperparathyroidism. METHODS We present the case history, laboratory results, operative interventions, and pathologic findings in a 36-year-old woman. Relevant reports from the literature are reviewed. RESULTS Our patient, who had been undergoing long-term hemodialysis because of renal failure, presented with secondary hyperparathyroidism and progressive bone pain. After an uneventful subtotal parathyroidectomy (removal of 3-1/2 glands), her symptoms resolved in conjunction with normalization of parathyroid hormone levels. Subsequently, however, recurrent hyperparathyroidism and severe bone pain necessitated second and third neck explorations, during which parathyromatosis was discovered. A total thyroidectomy was performed because of the bilateral nature of the disease. Postoperatively, the patient's bone pain resolved substantially, although her parathyroid hormone levels remained high. CONCLUSION Parathyromatosis is a rare cause of recurrent hyperparathyroidism after parathyroidectomy. It consists of hyperfunctioning parathyroid tissues scattered throughout the neck, due either to intraoperative tissue spillage and subsequent implantation or to hyperplasia of parathyroid rests from embryologic development. This is one of the few case reports of parathyromatosis and the first case report of a mixed form of the disease, consisting of features of both subcapsular parathyroid rests and extracapsular implantation.
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Nutton RW, Fitzgerald RH, Brown ML, Kelly PJ. Dynamic radioisotope bone imaging as a noninvasive indicator of canine tibial blood flow. J Orthop Res 2001; 2:67-74. [PMID: 6491801 DOI: 10.1002/jor.1100020111] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The relative values of dynamic and static bone imaging with hydroxymethylenediphosphonate technetium 99m (99mTc HDP) as an indicator of bone blood flow was investigated in the tibia of mature dogs. The dynamic bone scan consisted of 60 1-s images formed after the intravenous injection of 99mTc HDP, and the static bone scan was a 45-min uptake image. Blood flow to the tibia was determined by using radioactively labeled microspheres. Studies were carried out in control dogs, in dogs in which blood flow was increased in one leg with ATP, and in dogs in which blood flow was decreased in one leg with norepinephrine. A significant (p less than 0.001) linear relationship between the dynamic scan values and bone blood flow was found at a wide range of blood flow rates. When blood flow increased by more than 50%, the effects of "diffusion limitation" were seen in the static scans: increase in tracer uptake was disproportionately small for a significant increase in blood flow. There is no method currently available for estimating bone blood flow by a noninvasive technique. The method described here may be useful for providing a semiquantitative measure of bone blood flow. This improved versatility of bone imaging may have a role in the management of osteomyelitis or complicated fractures, or in assessing the viability of vascularized bone grafts.
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Rieger JM, Brown ML, Sullivan GW, Linden J, Macdonald TL. Design, synthesis, and evaluation of novel A2A adenosine receptor agonists. J Med Chem 2001; 44:531-9. [PMID: 11170643 DOI: 10.1021/jm0003642] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We have been interested in the design, synthesis, and evaluation of novel adenosine A2A agonists. Through the use of comparative molecular field analysis (CoMFA) we have generated a training model that includes 78 structurally diverse A2A agonists and correlated their affinity for isolated rat brain receptors with differences in their structural and electrostatic properties. We validated this model by predicting the activity of a test set that included 24 additional A2A agonists. Our CoMFA model, which incorporates the physiochemical property of dipole and selects against A1 receptor activity, generated a correlated final model (r2 = 0.891) that provides for enhanced A2A selectivity and predictability. Synthesis, pharmacological evaluation, and modeling of four novel ligands further validate the utility and predictive power (r2 = 0.626) of the CoMFA model.
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Mauk RJ, Brown ML. Selenium and mercury concentrations in brood-stock walleye collected from three sites on Lake Oahe. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2001; 40:257-263. [PMID: 11243328 DOI: 10.1007/s002440010170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A decline in the walleye Stizostedion vitreum sport fishery in lower Lake Oahe, South Dakota, was documented in the early 1980s and has been attributed to poor natural reproduction and/or recruitment. Contaminants were suspected of causing low natural reproduction/recruitment in lower Lake Oahe as well as low hatchability of eggs produced from broodstock walleyes taken from lower Lake Oahe. Concentrations of dissolved selenium in the Cheyenne River, which enters lower Lake Oahe, have increased considerably over the last 15 years. To determine whether selenium concentrations contributed to the reproduction problems in the lower Lake Oahe walleye population, adult walleye were collected during spawning operations in April 1994, 1995, and 1996 to obtain tissue samples. Muscle, liver, reproductive tissue, and unfertilized eggs were analyzed with a modified fluorometric method for determining selenium concentrations in plants. These tissues were also analyzed for mercury content using cold-vapor atomic absorption. No statistical differences (p < 0.05) in selenium or mercury concentrations among sites could be determined that would explain differential walleye egg hatchability. Correlation analysis determined significant inverse associations existed between the gonadal somatic index of male walleye and gonadal tissue selenium concentrations (r = -0.41, p = 0.0012). Both walleye sexes exhibited significant inverse associations between the hepatic somatic index (HSI) and liver selenium concentrations (males r = -0.33, p = 0.0095; and females r = -0.38, p = 0.0034). Positive relationships existed for female walleye selenium concentrations in the liver and the ovaries (r = 0.37, p = 0.003) and the liver and muscle tissue (r = 0.28, p = 0.027). Mercury concentrations in walleye ovaries were positively correlated with HSI (r = 0.30, p = 0.0012), length (r = 0.36, p = 0.0046), relative weight (r = 0.36, p = 0.0054), and muscle concentrations (r = 0.49, p = 0.0001). Mercury concentrations in male walleye muscle were correlated with age (r = 0.57, p = 0.0001), length (r = 0.79, p = 0.0001), and mercury concentrations in the testes (r = 0.43, p = 0.0006).
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Rockette HE, Li W, Brown ML, Britton CA, Towers JT, Gur D. Statistical test to assess rank-order imaging studies. Acad Radiol 2001; 8:24-30. [PMID: 11201453 DOI: 10.1016/s1076-6332(03)80740-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES Rank-order experiments often provide a reasonable method of determining whether a large-scale receiver operating characteristic study can be justified. The authors' purpose was to formalize a proposed method for analyzing rank-order imaging experiments and provide methods that can be used in determining sample sizes for both cases and raters. MATERIALS AND METHODS Simulations were conducted to determine the adequacy of the normal approximation of a statistic used to test the null hypothesis of random ordering. For a multireader experiment, formulas are presented and guidelines are provided to enable investigators to determine the number of required readers (raters) and cases for a specific study. RESULTS When there are at least five ordered images per case, 10 cases are sufficient to test a random rank order. When there are only three or four images for a case, 20 cases are required. The authors constructed tables of statistical power for selected numbers of ordered images, numbers of cases, and degrees of trend, and they also provide an approximation for use in situations that are not tabled. CONCLUSION The statistical methods for analyzing rank-order experiments and estimating sample sizes for study planning are relatively simple to implement. The derived formulas for sample size estimation, when applied to typical imaging experiments, indicate that modest numbers of cases and readers are required for rank-order studies.
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Brown ML, Lew S, Chang Y. The scid recombination-inducible cell line: a model to study DNA-PK-independent V(D)J recombination. Immunol Lett 2000; 75:21-6. [PMID: 11163862 DOI: 10.1016/s0165-2478(00)00283-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
To investigate the molecular mechanisms of the variable (diversity) joining (V(D)J) recombination process at an endogenous gene locus, recombination-inducible cell lines were made from both bcl-2-bearing severe combined immune deficiency (scid) homozygous and scid heterozyous (s/ + ) mice by transforming pre-B cells with the temperature-sensitive Abelson murine leukemia virus (ts-Ab-MLV). These transformants can be induced to undergo immunoglobulin light-chain gene rearrangements by incubating them at the non-permissive temperature. In the case of transformed scid cells, a significant amount of hairpin coding ends are accumulated during recombination induction, but few coding joints are generated. After being shifted to the permissive temperature. however, these cells are capable of opening hairpin ends and forming coding joints. Thus, ts-Ab-MLV transformed scid cells can be readily manipulated for both recombination cleavage and end resolution. However, unlike the rapid coding joint formation in s/ + cells that have the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), the process for resolving coding ends in scid cells is slow and error prone, and also appears to be correlated with a reduction in the RAG1/2 expression. Apparently, this process is mediated by a DNA-PK-independent pathway. The fact that the activity of this pathway can be manipulated in vitro makes it possible to delineate the mechanisms in end opening, processing and joining. Therefore, these ts-Ab-MLV transformed scid cell lines offer a model to study the molecular nature as well as the regulation of the DNA-PK-independent pathway in coding end resolution.
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Loeve F, Brown ML, Boer R, Habbema JD. Re: improving the cost-effectiveness of colorectal cancer screening. J Natl Cancer Inst 2000; 92:1691-2. [PMID: 11036117 DOI: 10.1093/jnci/92.20.1691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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