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Dave L. Demets, Professor, Department of Biostatistics & Medical Informatics
David L. DeMets

Professor, Department of Biostatistics & Medical Informatics
Ph.D., 1970, University of Minnesota  
Room 201 WARF
610 Walnut Street
Madison, WI 53726

FAX: 608-263-0415
  *Please Note - Questions concerning graduate training in biostatistics should be emailed directly to admissions staff:
David DeMets Biosketch
  Software: Programs for Computing Group Sequential Boundaries using the Lan-DeMets Method
Courses Taught
Spring 1992-2007 Biostatistics and Medical Informatics 542 (Introduction to Clinical Trials)
Clinical Trials Online Lectures
Research Interests
Methods for the analyses of clinical trials, sequential methods used for interim analysis, monitoring accumulating data for clinical trials, survival and longitudinal studies.

Dr. DeMets has over 200 publications. Complete List.

Selected Publications

Below is a sampling with links to abstracts or full text when available:

Statistical Methods Papers

DeMets D, Halperin M: "Estimation of a simple regression coefficient in samples arising from a sub-sampling procedure. " Biometrics, 33:47-56, 1977.

Wu M, Fisher M, DeMets D: "Sample sizes for long-term medical trials with time-dependent dropout and event rates." Controlled Clinical Trials, 1:109-121, 1980. Abstract: PubMed.

DeMets DL, Ware JH: "Asymmetric group sequential boundaries for monitoring clinical trials." Biometrika, 69(3):661-663, 1982.

Lan KKG, DeMets DL: "Discrete sequential boundaries for clinical trials". Biometrika, 70(3):659-663, 1983.

Kim K, DeMets DL: "Design and analysis of group sequential tests based on the type I error spending rate function". Biometrika, 74:149-154, 1987.

Kim K, DeMets DL: "Confidence intervals following group sequential tests in clinical trials". Biometrics, 43:857-864, 1987.

Storer B, DeMets D: "Current Phase I/II designs: Are they adequate?" Journal of Clinical Research and Drug Development, 1:121-130, 1987.

Lan KKG, DeMets DL: "Changing frequency of interim analyses in sequential monitoring". Biometrics, 45:1017-1020, 1989. Abstract: PubMed.

DeMets DL: "Group sequential procedures: Calendar versus information time". Statistics in Medicine, 8:1191-1198, 1989. Abstract: PubMed.

Lee JW, DeMets DL: "Sequential comparison of changes with repeated measurement data." Journal of the American Statistical Association, 86(415):757-762, 1991.

DeMets DL, Lan KKG: "Interim analysis: The alpha spending function approach". Statistics in Medicine, 13:1341-1352, 1994. Abstract: PubMed.

Lan KKG, Reboussin DM, DeMets DL: "Information and information fractions for design and sequential monitoring of clinical trials". Communications in Statistics-Theory and Methods, 23(2):403-420, 1994.

Gange SJ, Linton KLP, Scott AJ, DeMets DL, Klein R: "A comparison of methods for correlated ordinal measures with ophthalmic applications." Statistics in Medicine, 14:1961-1974, 1995. Abstract: PubMed.

Gange SJ, DeMets DL: "Sequential monitoring of clinical trials with correlated categorical responses". Biometrika, 83(1):157-167, 1996.

Reboussin DM, DeMets DL: "Exact permutation inference for two sample repeated measures data." Communications in Statistics, 25(10):2223-2238, 1996.

Pinheiro JC, DeMets DL: "Estimating and reducing bias in group sequential designs with Gaussian independent structure." Biometrika, 84:831-843, 1997.

Li Z, DeMets DL: "On the Bias of estimation of a Brownian motion drift following group sequential tests." Statistical Sinica, 9(4):923-937, 1999.

Reboussin DM, DeMets DL, Kim KM, Lan KKG: "Computations for group sequential boundaries using the Lan-DeMets spending function method." Controlled Clinical Trials, 21(3):190-207, 2000. Abstract: PubMed, Full Text: Elsevier.

Gong J, DeMets DL, Pinheiro JC: "Estimating significance level and power comparisons for testing multiple endpoints in clinical trials." Controlled Clinical Trials, 21(4):313-329, 2000. Abstract: PubMed.

Lee JW, Jo SJ, DeMets DL, Kim K: "Confidence intervals following group sequential tests in clinical trials with multivariate observations." J Statist Comput Simul, 72(3): 247-59, 2002.

Chen JYH, DeMets DL, Lan KKG. "Monitoring mortality at interim analyses while testing a composite endpoint at the final analysis." Controlled Clinical Trials, 23:16-27, 2003. Abstract: PubMed, Full Text: Elsevier site .

Chen JYH, DeMets DL, Lan G. "Increasing the sample size when the unblinded interim result is promising." Statistics in Medicine, 23(7): 1023-1038, 2004. Abstract and Full Text: Wiley InterScience.

DeMets DL, Fleming TR. "The independent statistician." Statistics in Medicine, 23:1513-1517, 2004.

Fan X, DeMets DL. "Conditional bias adjustment in group sequential clinical trials (MERIT-HF, BHAT and CAST)." Accepted, Statistics in Medicine, 2004.

Chen JYH, DeMets DL, Lan KKG. Monitoring morality at interim analyses while testing a composite endpoint at the final analysis. Controlled Clinical Trials 23:16-27, 2003.

Chen JYH, DeMets DL, Lan KKG. Increasing the sample size when the unblinded interim result is promising. Statistics in Medicine 23(7):1023-1038, 2004.

Fan X, DeMets DL, and Lan KKG. Conditional bias of point estimates following a group sequential test. Journal of Biopharmaceutical Statistics, 14:505-530, 2004.

Kosorok MR, Shi Y, DeMets DL: Design and analysis of group sequential clinical trials with multiple primary endpoints. Biometrics 60(1):134-45, 2004.

Fan X. DeMets DL. Conditional and unconditional confidence intervals following a group sequential test. Journal of Biopharmaceutical Statistics 16:107-122, 2006.

Lan KKG and DeMets D. Further comments on the alpha-spending function. Stat Biosci 1:95-111, 2009.

Collaborative Papers through 2006

Byar DP, Simon RM, Friedewald WT, Schlesselman JJ, DeMets DL, Ellenberg JH, Gail MH, Ware JH: "Randomized clinical trials - Perspectives on some recent ideas." New England Journal of Medicine, 294:74 80, 1976. Abstract: PubMed.

Friedman L, DeMets D: "The data monitoring committee: How it operates and why." Institutional Review Board, 3:6-8, 1981.

May GS, DeMets DL, Friedman LM, Furberg C, Passamani G: "The randomized clinical trial: Bias in analysis." Circulation, 64(4):669 673, 1981. Abstract: PubMed.

DeMets DL, Hardy R, Friedman LM, Lan KKG: "Statistical aspects of early termination in the Beta-Blocker Heart Attack Trial." Controlled Clinical Trials, 5:362 372, 1984. Abstract: PubMed.

Williams GW, Snedecor SM, DeMets DL, and the NOTT Research Group: Recruitment experience in the Nocturnal Oxygen Therapy Trial. Controlled Clinical Trials, 8:121S 130S, 1987. Abstract: PubMed.

DeMets DL: "Methodological issues in AIDS clinical trials. Data monitoring and sequential analysis--an academic perspective." Journal of Acquired Immune Deficiency Syndrome, 3(Suppl 2):S124-S133, 1990.

Cairns J, Cohen L, Colton T, DeMets DL, Deykin D, Friedman L, Greenwald P, Hutchinson GB, Rosner B: "Issues in the early termination of the aspirin component of the Physician's Health Study. Data Monitoring Board of the Physicians' Health Study." Annals of Epidemiology, 1(5):395-405, 1991. Abstract: PubMed.

DeMets DL, Meinert CL: "Data Integrity." Controlled Clinical Trials, 12:727-730, 1991.

Fleming TR, DeMets DL: "Monitoring of Clinical Trials: Issues and Recommendations." Controlled Clinical Trials, 14:183-197, 1993. Abstract: PubMed.

"Task Force of the Working Group on Arrhythmias of the European Society of Cardiology: The early termination of clinical trials: Causes, consequences, and control - with special reference to trials in the field of arrhythmias and sudden death". Circulation, 89(6):2892-2907, 1994. Abstract: PubMed.

Fleming TR, DeMets DL: "Surrogate endpoints in clinical trials: Are we being misled?" Annals of Internal Medicine, 125(7):605-613, 1996. Full Text: Annals website.

DeMets DL: "Statistics and ethics in medical research." Science & Engineering Ethics, 5(1):97-117, 1999.

DeMets DL, Pocock S, Julian DG: "The agonising negative trend in monitoring clinical trials." Lancet, 354:1983-1988, 1999. Abstract: PubMed, Full Text: Elsevier site.

DeMets DL: "Design of Phase II trials in congestive heart failure." American Heart Journal, 139:S207-S210, 2000.

DeMets DL: "The role of surrogate outcome measures in evaluating medical devices." Surgery, 128(3):379-385, 2000.

Fisher M, Roecker EB, DeMets DL: "The role of an independent statistical analysis center in the industry-modified National Institutes of Health model." Drug Information Journal, 35(1):115-129, 2001. Full Text: DIA website.

Wedel H, DeMets D, Deedwania P, Fagerberg B, Goldstein S, Gottlieb S, Hjalmarson Å, Kjekshus J, Waagstein F, Wikstrand J on behalf of the MERIT-HF Study Group: "Challenges of subgroup analyses in multinational clinical trials: Experiences from the Merit-HF trial." American Heart Journal, 142(3):502-11, 2001. Abstract: PubMed.

Califf RM and DeMets DL: "Principles from clinical trials relevant to clinical practice: Part I." Circulation, 106: 1015-1021, 2002. Full Text: Circulation website.

Califf RM and DeMets DL: "Principles from clinical trials relevant to clinical practice: Part II." Circulation, 106: 1172-1175, 2002. Full Text: Circulation website.

DeMets DL and Califf RM: "Lessons learned from recent cardiovascular clinical trials: Part I." Circulation, 106:746-51, 2002. Full Text: Circulation website.

DeMets DL and Califf RM: "Lessons learned from recent cardiovascular clinical trials: Part II." Circulation, 106:880-86, 2002. Full Text: Circulation website.

DeMets DL: "Clinical trials in the new millennium." Statistics in Medicine, 21:2779-2787, 2002. Abstract: PubMed, Full Text: Wiley InterScience.

Fleming TR, Ellenberg S, DeMets DL: "Monitoring clinical trials: issues and controversies regarding confidentiality." Statistics in Medicine, 21:2843-51, 2002. Abstract: PubMed, Full Text: Wiley InterScience.

Packer M, Fowler MB, Roecker EB, Coats AJS, Katus HA, Krum H, Mohaschi P, Rouleau JL, Tendera M, Staiger C, Holcslaw T, Amann-Zalan I, DeMEts DL. Effect of carvedilol on the morbidity of patients with severe chronic heart failure- Results of the Carvedilol Prospective Randomized Cumulative Survival (CORPERNICUS) study. Circulation, 106(17):2559-66, 2002.

Califf RM, Morse MA, Wittes J, Goodman SN, Nelson DK, DeMets DL, Iafrate RP, Sugarman J. Toward protecting the safety of participants in clinical trials. Controlled Clinical Trials 24:256-71, 2003.

DeMets DL , Califf RM, Dixon D, Ellenberg S, Fleming T, Held P, Julian D, Kaplan R, Levine R, Neaton J, Packer M, Pocock S, Rockhold F, Seto B, Siegel J, Snapinn S, Stump D, Temple R, Whitley. Issues in regulatory guidelines for data monitoring committees. Clinical Trials 1:162-69, 2004.

DeMets DL, and Flemming TR. The independent statistician for data monitoring committees. Statistics in Medicine 23:1513-1517, 2004.

Bristow MR, Saxon LA, Boehmer J, Boehmer J, Krueger s, Kass D, DeMarco T, Carson P, DiCarlo L, DeMets D, White BG, DeVries DW, Feldman AM for the Comparison of Medical Therapy, Pacing and Defibrillation in Heart Failure (COMPANION) Investigators. Cardiac resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. New Eng J Med 350:2140-50, 2004.

DeMets DL, Flemming TR, Rockold R, Massie B, Merchant T, Meisel A, Mishkin B, Wittes J, Stump, D, Califf R. Liability issues for data monitoring committee members. Clinical Trials 1:525-31, 2004.

DeMets DL, Fost N, Powers M. An Institutional Board Dilemma:Responsible for safety monitoring but not in control. Clinical Trials 3:142-148, 2006.

Society for Clinical Trials Board of Directors (Begg CB, Brawley O, Califf RM, DeMets DL, Ellenberg SS, Kaplan RS, Rockhold RW on behalf of the Society for Clinical Trials). The Society for Clinical Trials opposes US legislation to permit marketing of unproven medical therapies for seriously ill patients. Clinical Trials 3: 154-57, 2006.

DeMets DL, Stormo G, Boehnke M, Louis TA, Taylor J, Dixon D. Training of the next generation of biostatisticians: a call to action in the U.S. Stat Med 25:3415-29, 2006.

DeMets DL. Futility Approaches to Interim Monitoring by Data Monitoring Committees. Clinical Trials 3:522-529, 2006.

Baron JA, Sandler RS, Bresalier RS, Lanas A, Morton DG, Riddell R, Iverson ER, DeMets DL. Cardio-vascular events associated with rofecoxib: final analysis of the APPROVe trial. Lancet 372(9651):1756-64.

Hennekens CH, DeMets DL, Bairey Merz CN, Borzak SL, Borer JS. Doing more good than harm: need for a cease fire. Am J Med. 122(4):315-6, 2009.

Anand IS, Carson P, Galle E, Song R, Bochmer J, Ghali JK, Jaski B, Lindenfeld J, O’Connor C, Steinberg JS, Leigh J, Yong P, Kosorok MR, Feldman AM, DeMets D, and Bristow MR. Cardiac resynchronization therapy reduces the risk of hospitalizations in patients with advanced heart failure. Results from the Comparison of Medical Therapy, Pacing and Defibrillation in Heart Failure (COMPANION) Trial. Circulation119(7):969-77, 2009.

Metra M, Eichhorn E, Abraham WT, Linseman J, Böhm M, Corbalan R, DeMets D, DeMarco T, Elkayam U, Gerber M, Komajda M, Liu P, Mareev V, Perrone SV, Poole-Wilson P, Roecker E, Stewart J, Swedberg K, Tendera M, Wiens B, Bristow MR for the ESSENTIAL Investigators. Effects of low-dose oral enoximone administration on mortality, morbidity and exercise capacity in patients with advanced heart failure: the randomized, double-blind, placebo-controlled, parallel group ESSENTIAL trials. Eur Heart J Aug 22, 2009. doi:10.1093/eurheartj/ehp338


DeMets DL and Lan KKG: The Alpha Spending Function Approach to Interim Data Analyses. In: Recent Advances in Clinical Trial Design and Analysis. P. Thall (Ed.), Kluver Academic Publishers, 1995. pp.1-27.

Friedman L, Furberg C, DeMets DL: Fundamentals of Clinical Trials. John Wright-PSG Inc., Littleton, MA, 1981; 2nd edition 1985; Mosby-Year Book, Inc., St. Louis MO. 3rd edition 1996; Springer-Verlag, New York, NY.

DeMets DL: Data and Safety Monitoring Boards. In: Encyclopedia of Biostatistics. L. Freedman (section ed.), P. Armitage, T. Colton (editors in chief), John Wiley and Sons, West Sussex, England, 1998, Volume 2, pp. 1067-71.

Ellenberg S, Fleming T and DeMets D: Data Monitoring Committees in Clinical Trials: A Practical Perspective. John Wiley & Sons, Ltd., West Sussex, England, 2002.

DeMets D, Fisher M: "Fundamentals of Biostatistics." In: A Physician’s Guide to Healthcare Management. D. Albert (ed.), Blackwell Science, Inc., Oxford, England, 2002, pp. 122-130.

Ellenberg S, Fleming T, DeMets DL: "Data Monitoring Committees." In Clinical Trials: a Practical Perspective. John Wiley and Sons, Ltd., West Sussex, England, 2002.

DeMets DL, Friedman L, Fuberg CD. Data Monitoring in Clinical Trials: A Case Studies Approach. Springer Science + Business Media, New York, NY, 2005.

Cook T and DeMets DL. Introduction to Statistical Methods for Clinical Trials, Chapman & Hall/CRC; Taylor & Francis Group, LLC, Boca Raton, FL, 2008.

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