M J Klag

Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States

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Publications (88)911.21 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Bookman et al. write to correct the impression given in the Commentary by Kohane and Taylor that the recommendations of the National Heart, Lung, and Blood Institute (NHLBI) Working Group "Reporting Genetic Results in Research Studies" included advice to return genetic information to research subjects only in cases where there is a proven or preventative intervention for the identified disorder. In fact, the report does recommend that genetic information be returned to subjects when there is an intervention available, but it does not recommend against giving this kind of information to subjects if there is no available intervention.
    Science translational medicine 02/2011; 3(70):70le1. DOI:10.1126/scitranslmed.3001516 · 15.84 Impact Factor
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    ABSTRACT: FORECASTAs a result, today's public health workforce, faced with daunting public health challenges, has been forced to do more with fewer people. For example, in the U.S. in the year 2000, there were about 50,000 fewer public health employees than in 1980.5,6 While the 1980 workforce ratio (220 per 100,000) may in fact be an underestimate of the ideal number of public health workers, it provides a benchmark for estimating current and future needs.2 And although technological advances may to some extent mitigate the impact of the decrease in the size of the public health workforce, this trend cannot continue without drastically compromising the public's health.To have the same public health workforce-to-population ratio in 2000 as existed in 1980, there would have had to have been more than 600,000 public health workers, or an additional 150,000 on top of the 450,000 that existed at the time. In 2020, to have the same ratio (220:100,000), the public health workforce would need to number 700,000+, or 250,000+ workers more than the most recent count.More than 50% of states cite the lack of trained personnel as a major barrier to our nation's preparedness.7 Additionally, a recent Institute of Medicine (IOM) report states that there is a shortage of 10,000 public health physicians—double the amount estimated to be practicing currently.8 Other reports have documented and forecast shortages among public health nurses, epidemiologists, health-care educators, and administrators. Moreover, there are demonstrated disparities in the public health workforce related to racial and ethnic parity, as well as geographic maldistribution. As stated by the Sullivan Commission on Diversity in the Healthcare Workforce: “Today's physicians, nurses, and dentists have too little resemblance to the diverse populations they serve, leaving many Americans feeling excluded by a system that seems distant and uncaring. The fact that the nation's health professions have not kept pace with changing demographics may be an even greater cause of disparities in health access and outcomes than the persistent lack of health insurance for tens of millions of Americans.”9Public health workforce shortages are even more critical in much of the developing world. For example, despite representing 11% of the world's population and 24% of the global burden of disease, sub-Saharan Africa has only 3% of the world's health workers and commands less than 1% of the world's health expenditures.10 The 2006 World Health Report states that there is a “major mismatch” between population needs and the available public health workforce in terms of overall numbers, relevant training, practical competencies, and sufficient diversity to serve all individuals and communities. Multifaceted efforts are needed to increase the capacity of the global public health workforce, given the increasingly easy cross-country transmission of disease.11Retirement projections of public health professionals are not available for most private-sector positions. However, for the public sector, the estimated retirement potential is sobering (Table 2). If we assume that the public health workforce numbered 450,000 in the years when each of the retirement waves is projected (2003, 2010, 2012), then by 2012 a total of more than 100,000 public health workers (or 23% of the current workforce) will retire, leaving a large void of expertise to be filled. Of note, this projected retirement wave will place an added burden on the looming workforce shortage of 250,000 estimated for 2020.Table 2Percent of public health workers eligible to retire by 2012 (n=450,000)
    Public Health Reports 06/2008; 123(3):395-8. · 1.55 Impact Factor
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    ABSTRACT: African American men with chronic kidney disease (CKD) progress to end-stage renal disease more rapidly than African American women or whites. Uncontrolled hypertension worsens CKD, and disparities in hypertension control may contribute to disparities in CKD progression. Cross-sectional. 10,827 individuals with CKD and self-reported hypertension screened in the Kidney Early Evaluation Program. African American race, sex. Hypertension control (blood pressure <130 mm Hg systolic and/or <80 mm Hg diastolic). Self-report, physical examination (blood pressure), laboratory data (serum creatinine, microalbuminuria by urine dipstick). We calculated estimated glomerular filtration rates by using the 4-variable isotope dilution mass spectrometry Modification of Diet in Renal Disease Study equation. We classified CKD as early (stages 1 to 2) or late (stages 3 to 5) based on estimated glomerular filtration rate and microalbuminuria. In individuals with early CKD, African American women (odds ratio [OR], 1.47; 95% confidence interval [CI], 1.14 to 1.88), white men (OR, 1.85; 95% CI, 1.39 to 2.46), and white women (OR, 1.69; 95% CI, 1.28 to 2.22) had greater odds of hypertension control (blood pressure <130/80 mm Hg) than African American men. In individuals with late CKD, white men (OR, 1.66; 95% CI, 1.10 to 2.52) and white women (OR, 1.67; 95% CI, 1.13 to 2.46) had greater odds of hypertension control than African American men. No differences were seen between African American men and women with late CKD. No information for medication regimens. African American men with CKD have poorly controlled hypertension compared with African American women and whites, particularly in the early stages of disease. Efforts to aggressively treat hypertension in this population may help narrow the race and sex disparities in progression to end-stage renal disease.
    American Journal of Kidney Diseases 03/2008; 51(2):192-8. DOI:10.1053/j.ajkd.2007.09.023 · 5.90 Impact Factor
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    ABSTRACT: To determine associations between home remedy use and self-reported adherence among urban African Americans with poorly controlled hypertension. A cross-sectional structured interview of African Americans admitted to medical units for uncontrolled hypertension at an urban academic hospital from 1999-2004. Logistic regression was used to test associations between home remedy use and self-reported adherence. One-hundred-eighty-three of 272 participants completed the study (67%); 39 (21%) reported using home remedies for hypertension. In a multivariate model, home remedy use was independently associated with greater medication adherence (OR for nonadherence=0.32, 95% CI: 0.14-0.75; p<0.01) and dietary adherence (OR for changing diet=3.28, 95% CI: 1.10-9.81; p=0.03), but not lifestyle or appointment adherence. These associations remained strong while controlling for age; sex; employment status; and key covariates, including greater medication side effects (OR=4.31; 95% CI: 1.64-11.3; p<0.01), greater difficulty paying for medications (OR=2.94, 95% CI: 1.25-6.92; p=0.01) and longer duration of diagnosis (OR for log years=1.53; 95% CI: 1.02-2.33; p=0.045). Home remedy use may be a marker of positive self-care for some hypertensive African Americans and not a promoter of nonadherence.
    Journal of the National Medical Association 01/2008; 100(1):91-7. · 0.96 Impact Factor

  • American Journal of Kidney Diseases 04/2007; 49(4):B38. DOI:10.1053/j.ajkd.2007.02.058 · 5.90 Impact Factor
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    ABSTRACT: The extent which universally common or population-specific alleles can explain between-population variations in phenotypes is unknown. The heritable coronary heart disease risk factor lipoprotein(a) (Lp(a)) level provides a useful case study of between-population variation, as the aetiology of twofold higher Lp(a) levels in African populations compared with non-African populations is unknown. To evaluate the association between LPA sequence variations and Lp(a) in European Americans and African Americans and to determine the extent to which LPA sequence variations can account for between-population variations in Lp(a). Serum Lp(a) and isoform measurements were examined in 534 European Americans and 249 African Americans from the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease Study. In addition, 12 LPA variants were genotyped, including 8 previously reported LPA variants with a frequency of >2% in European Americans or African Americans, and four new variants. Isoform-adjusted Lp(a) level was 2.23-fold higher among African Americans. Three single-nucleotide polymorphisms (SNPs) were independently associated with Lp(a) level (p<0.02 in both populations). The Lp(a)-increasing SNP (G-21A, which increases promoter activity) was more common in African Americans, whereas the Lp(a)-lowering SNPs (T3888P and G+1/inKIV-8A, which inhibit Lp(a) assembly) were more common in European Americans, but all had a frequency of <20% in one or both populations. Together, they reduced the isoform-adjusted African American Lp(a) increase from 2.23 to 1.37-fold(a 60% reduction) and the between-population Lp(a) variance from 5.5% to 0.5%. Multiple low-prevalence alleles in LPA can account for the large between-population difference in serum Lp(a) levels between European Americans and African Americans.
    Journal of Medical Genetics 12/2006; 43(12):917-23. DOI:10.1136/jmg.2006.042119 · 6.34 Impact Factor
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    ABSTRACT: Elevated bone mineral parameters have been associated with mortality in dialysis patients. There are conflicting data about calcium, parathyroid hormone (PTH), and mortality and few data about changes in bone mineral parameters over time. We conducted a prospective cohort study of 1007 incident hemodialysis and peritoneal dialysis patients. We examined longitudinal changes in bone mineral parameters and whether their associations with mortality were independent of time on dialysis, inflammation, and comorbidity. Serum calcium, phosphate, and calcium-phosphate product (CaP) increased in these patients between baseline and 6 months (P<0.001) and then remained stable. Serum PTH decreased over the first year (P<0.001). In Cox proportional hazards models adjusting for inflammation, comorbidity, and other confounders, the highest quartile of phosphate was associated with a hazard ratio (HR) of 1.57 (1.07-2.30) using both baseline and time-dependent values. The highest quartiles of calcium, CaP, and PTH were associated with mortality in time-dependent models but not in those using baseline values. The lowest quartile of PTH was associated with an HR of 0.65 (0.44-0.98) in the time-dependent model with 6-month lag analysis. We conclude that high levels of phosphate both at baseline and over follow-up are associated with mortality in incident dialysis patients. High levels of calcium, CaP, and PTH are associated with mortality immediately preceding an event. Promising new interventions need to be rigorously tested in clinical trials for their ability to achieve normalization of bone mineral parameters and reduce deaths of dialysis patients.
    Kidney International 07/2006; 70(2):351-7. DOI:10.1038/sj.ki.5001542 · 8.56 Impact Factor
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    ABSTRACT: Prospective epidemiologic studies aid in identifying genetic variants associated with diseases, health risks, and physiologic traits. These genetic variants may eventually be measured clinically for purposes of diagnosis, prognosis, and treatment. As evidence of the potential clinical value of such information accrues, research studies face growing pressure to report these results to study participants or their physicians, even before sufficient evidence is available to support widespread screening of asymptomatic persons. There is thus a need to begin to develop consensus on whether and when genetic findings should be reported to participants in research studies. The National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group on Reporting Genetic Results in Research Studies to discuss if, when, and how genetic information should be reported to study participants. The Working Group concluded that genetic test results should be reported to study participants when the associated risk for the disease is significant; the disease has important health implications such as premature death or substantial morbidity or has significant reproductive implications; and proven therapeutic or preventive interventions are available. Finally, the Working Group recommended procedures for reporting genetic research results and encouraged increased efforts to create uniform guidelines for this activity.
    American Journal of Medical Genetics Part A 05/2006; 140(10):1033-40. DOI:10.1002/ajmg.a.31195 · 2.16 Impact Factor
  • LC Plantinga · NE Fink · BG Jaar · JH Sadler · J Coresh · MJ Klag · AS Levey · NR Powe ·

    Seminars in Dialysis 05/2005; 18(3). DOI:10.1111/j.1525-139X.2005.18324.x · 1.75 Impact Factor
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    J H Young · P Parler · B Bristol · M J Klag ·
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    ABSTRACT: Eastern Europe is experiencing an epidemic of cardiovascular disease far outpacing rates in Western Europe. This epidemic was heralded by a precipitous rise in hypertension prevalence. The former Soviet states of Central Asia may be facing a similar epidemic. In order to access this threat, we performed a retrospective analysis of data generated during humanitarian medical visits to two villages in Kyrgyzstan, Central Asia. The age-adjusted prevalence of hypertension was 39%. Hypertension was much more common among men than women (46 vs 33%, respectively). In addition, the rise in blood pressure with age was striking, surpassing the experience in Western countries. This epidemic of hypertension may herald a coming epidemic of cardiovascular disease in Central Asia.
    Journal of Human Hypertension 03/2005; 19(2):145-8. DOI:10.1038/sj.jhh.1001791 · 2.70 Impact Factor
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    ABSTRACT: BACKGROUND: Bisphosphonates are potent therapies for osteoporosis, but some patients cannot tolerate oral forms. Our study sought to examine the effectiveness and safety of intravenous pamidronate as an alternate osteoporotic therapy in these patients. METHODS: We conducted a retrospective study of 26 patients treated with intermittent, intravenous pamidronate (30 mg every 3 months) and 52 matched controls treated with standard therapy, all with osteoporosis. Primary outcome was response to therapy, defined as either stabilization or increase in bone mineral density. Secondary outcomes were patient safety and tolerability. RESULTS: At an average of 16.1 months of follow up, 64% of pamidronate-treated patients responded to therapy at the lumbar spine, 65% at the femoral neck, and 63% at the trochanter. These response rates were not significantly different than those of the standard care group in which 69% were receiving oral bisphosphonates. Adverse events were uncommon and included mild, diffuse myalgi
    JCR Journal of Clinical Rheumatology 02/2005; 11(1):2-7. DOI:10.1097/01.rhu.0000152141.47663.e4 · 1.08 Impact Factor
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    ABSTRACT: Application of national guidelines regarding cardiovascular disease risk reduction to kidney dialysis patients is complicated by the conflicting observations that dialysis patients have a high risk of atherosclerotic cardiovascular disease (ASCVD), but dialysis patients with higher serum cholesterol have lower mortality rates. Actual treatment patterns of hyperlipidemia are not well studied. We assessed the prevalence, treatment and control of hyperlipidemia in this high-risk patient population from 1995 - 1998. We measured low-density lipoprotein cholesterol, treatment with a lipid-lowering agent, and prevalence of hyperlipidemia as defined by the National Cholesterol Education Program (NCEP), Adult Treatment Panel (ATP) II guidelines in 812 incident hemodialysis (HD), and peritoneal dialysis (PD) patients from dialysis clinics in 19 states throughout the United States. Hyperlipidemia was present in 40% of HD and 62% of PD patients. Among subjects with hyperlipidemia, 67% of HD and 63% of PD patients were untreated and only 22% of HD and 14% of PD patients were treated and controlled. Those who entered the study in 1997 or 1998, those with diabetes, males and Caucasians were more likely to be treated and controlled, whereas subjects on PD and those with ASCVD were less likely to be treated and controlled. These data suggest that high rates of undertreatment exist in the United States ESRD dialysis population. Whether improved rates of treatment will result in decreased cardiovascular disease events needs to be tested in randomized clinical trials.
    Clinical nephrology 06/2004; 61(5):299-307. DOI:10.5414/CNP61299 · 1.13 Impact Factor
  • M.J. Klag · N.H. Wang · L.A. Meoni ·

    ACC Current Journal Review 09/2002; 11(5):29. DOI:10.1016/S1062-1458(02)00779-1
  • P. Muntner · J. Coresh · J.C. Smith · J. Eckfeldt · M.J. Klag ·

    Hipertensión y Riesgo Vascular 12/2001; 18(1):53–54. DOI:10.1016/S1889-1837(01)71110-5
  • J Coresh · G L Wei · G McQuillan · F L Brancati · A S Levey · C Jones · M J Klag ·
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    ABSTRACT: The prevalence and incidence of end-stage renal disease in the United States are increasing, but milder renal disease is much more common and may often go undiagnosed and undertreated. A cross-sectional study of a representative sample of the US population was conducted using 16 589 adult participants aged 17 years and older in the Third National Health and Nutrition Examination Survey (NHANES III) conducted from 1988 to 1994. An elevated serum creatinine level was defined as 141 micromol/L or higher (>/=1.6 mg/dL) for men and 124 micromol/L or higher (>/=1.4 mg/dL) for women (>99th percentile for healthy young adults) and was the main outcome measure. Higher systolic and diastolic blood pressures, presence of hypertension, antihypertensive medication use, older age, and diabetes mellitus were all associated with higher serum creatinine levels. An estimated 3.0% (5.6 million) of the civilian, noninstitutionalized US population had elevated serum creatinine levels, 70% of whom were hypertensive. Among hypertensive individuals with an elevated serum creatinine level, 75% received treatment. However, only 11% of all individuals with hypertension had their blood pressure reduced to lower than 130/85 mm Hg (the Sixth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommendation for hypertensive individuals with renal disease); 27% had a blood pressure lower than 140/90 mm Hg. Treated hypertensive individuals with an elevated creatinine level had a mean blood pressure of 147/77 mm Hg, 48% of whom were prescribed one antihypertensive medication. Elevated serum creatinine level, an indicator of chronic renal disease, is common and strongly related to inadequate treatment of high blood pressure.
    Archives of Internal Medicine 05/2001; 161(9):1207-16. · 17.33 Impact Factor
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    S H Jee · J He · L J Appel · P K Whelton · I Suh · M J Klag ·
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    ABSTRACT: Coffee drinking has been associated with increased serum cholesterol levels in some, but not all, studies. A Medline search of the English-language literature published prior to December 1998, a bibliography review, and consultations with experts were performed to identify 14 published trials of coffee consumption. Information was abstracted independently by two reviewers using a standardized protocol. With a random-effects model, treatment effects were estimated by pooling results from individual trials after weighting the results by the inverse of total variance. A dose-response relation between coffee consumption and both total cholesterol and LDL cholesterol was identified (p < 0.01). Increases in serum lipids were greater in studies of patients with hyperlipidemia and in trials of caffeinated or boiled coffee. Trials using filtered coffee demonstrated very little increase in serum cholesterol. Consumption of unfiltered, but not filtered, coffee increases serum levels of total and LDL cholesterol.
    American Journal of Epidemiology 02/2001; 153(4):353-62. · 5.23 Impact Factor
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    C P Gross · LA Mead · D E Ford · M J Klag ·
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    ABSTRACT: Little is known about the regular source of care (RSOC) among physicians, a group whose self-care may reflect the attitudes and recommendations they convey to their patients. We performed a cohort study of physicians who graduated from the Johns Hopkins School of Medicine from 1948 through 1964 to identify predictors of not having an RSOC, and to determine whether not having an RSOC was associated with subsequent receipt of preventive services. The RSOC was assessed in a 1991 survey; use of cancer screening tests and the influenza vaccine was assessed in 1997. The response rate in 1991 was 77% (915 respondents); 35% (312) had no RSOC. Internists (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.58-6.74), surgeons (OR, 2.42; 95% CI, 1.17-5.02), and pathologists (OR, 5.46; 95% CI, 2.09-14.29) were significantly more likely to not have an RSOC than pediatricians. Not having an RSOC was inversely related to the belief that health is determined by health professionals (OR, 0.45; 95% CI, 0.29-0.68) and directly related to the belief that chance (OR, 1.90; 95% CI, 1.28-2.82) determines health. Not having an RSOC in 1991 predicted not being screened for breast, colon, and prostate cancer, as well as not receiving an influenza vaccine at 6 years of follow-up. A large percentage of physicians in our sample had no RSOC, and this was associated with both medical specialty and beliefs about control of health outcomes. Not having an RSOC was significantly associated with failure to use preventive services several years later. Arch Intern Med. 2000;160:3209-3214.
    Archives of Internal Medicine 12/2000; 160(21):3209-14. DOI:10.1001/archinte.160.21.3209 · 17.33 Impact Factor
  • AC Gelber · M C Hochberg · LA Mead · NY Wang · F M Wigley · M J Klag ·
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    ABSTRACT: Knee and hip injuries have been linked with osteoarthritis in cross-sectional and case-control studies, but few prospective studies have examined the relation between injuries in young adults and risk for later osteoarthritis. To prospectively examine the relation between joint injury and incident knee and hip osteoarthritis. Prospective cohort study. Johns Hopkins Precursors Study. 1321 former medical students. Injury status at cohort entry was recorded when the mean age of participants was 22 years. Injury during follow-up and incident osteoarthritis were determined by using self-administered questionnaires. Osteoarthritis was confirmed by symptoms and radiographic findings. Over a median follow-up of 36 years, 141 participants reported joint injuries (knee alone [n = 111], hip alone [n = 16], or knee and hip [n = 14]) and 96 developed osteoarthritis (knee alone [n = 64], hip alone [n = 27], or knee and hip [n = 5]). The cumulative incidence of knee osteoarthritis by 65 years of age was 13.9% in participants who had a knee injury during adolescence and young adulthood and 6.0% in those who did not (P = 0.0045) (relative risk, 2.95 [95% CI, 1.35 to 6.45]). Joint injury at cohort entry or during follow-up substantially increased the risk for subsequent osteoarthritis at that site (relative risk, 5.17 [CI, 3.07 to 8.71] and 3.50 [CI, 0.84 to 14.69] for knee and hip, respectively). Results were similar for persons with osteoarthritis confirmed by radiographs and symptoms. Young adults with knee injuries are at considerably increased risk for osteoarthritis later in life and should be targeted in the primary prevention of osteoarthritis.
    Annals of internal medicine 10/2000; 133(5):321-8. DOI:10.7326/0003-4819-133-5-200009050-00007 · 17.81 Impact Factor
  • C M Loria · M J Klag · L E Caulfield · P K Whelton ·
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    ABSTRACT: Low vitamin C status may increase the risk of mortality from cancer and cardiovascular disease. The objective was to test whether an association existed between serum ascorbate concentrations and mortality and whether the association was modified by cigarette smoking status or sex. Serum ascorbate concentrations were measured in adults as part of the second National Health and Nutrition Examination Survey (1976-1980). Vital status was ascertained 12-16 y later. The relative risk (RR) of death, adjusted for potential confounders, was estimated by using Cox proportional hazards models. Men in the lowest (<28.4 micromol/L) compared with the highest (>/=73.8 micromol/L) serum ascorbate quartile had a 57% higher risk of dying from any cause (RR: 1.57; 95% CI: 1.21, 2.03) and a 62% higher risk of dying from cancer (RR: 1.62; 95% CI: 1.01, 2.59). In contrast, there was no increased risk among men in the middle 2 quartiles for these outcomes and no increased risk of cardiovascular disease mortality in any quartile. There was no association between serum ascorbate quartile and mortality among women. These findings were consistent when analyses were limited to nonsmokers or further to adults who never smoked, suggesting that the observed relations were not due to cigarette smoking. These data suggest that men with low serum ascorbate concentrations may have an increased risk of mortality, probably because of an increased risk of dying from cancer. In contrast, serum ascorbate concentrations were not related to mortality among women.
    American Journal of Clinical Nutrition 07/2000; 72(1):139-45. · 6.77 Impact Factor
  • F D Fuchs · M J Klag · P K Whelton ·

    Journal of Clinical Epidemiology 05/2000; 53(4):335-42. DOI:10.1016/S0895-4356(99)00185-7 · 3.42 Impact Factor

Publication Stats

7k Citations
911.21 Total Impact Points


  • 2008
    • Johns Hopkins Bloomberg School of Public Health
      • Department of Epidemiology
      Baltimore, Maryland, United States
  • 2007
    • The National Kidney Foundation
      New York, New York, United States
  • 1991-2006
    • Johns Hopkins University
      • • Department of Medicine
      • • Welch Center for Prevention, Epidemiology, and Clinical Research
      • • Department of Epidemiology
      Baltimore, Maryland, United States
  • 2000
    • National Heart, Lung, and Blood Institute
      • Division of Cardiovascular Sciences (DCVS)
      베서스다, Maryland, United States
  • 1990-1999
    • Johns Hopkins Medicine
      • • Welch Center for Prevention, Epidemiology and Clinical Research
      • • Department of Epidemiology
      • • Department of Health Policy and Management
      Baltimore, Maryland, United States