Edward L. Kaplan and the Kaplan-Meier Survival Curve

Abstract

In June 1958, Edward L Kaplan (1920–2006) and Paul Meier (1924–2011) published an innovative statistical method to estimate survival curves when including incomplete observations. The Kaplan–Meier (KM) method became the standard way of reporting patient survival in medical research. For example, the KM method is used in more than 70% of clinical oncology papers. With 44,319 Web of Science® citations as of November 2017, the report has become the most-cited statistics publication in the scientific literature. Part I of this report describes the KM method, its strengths and limitations, and the history and evolution of the method. In Part II we recount the biography of the remarkable mathematician Edward L Kaplan, PhD, and his unique contributions during the formulation of the KM method, as well as his contributions to science during his unique and productive career.

Acknowledgements

Mrs Mae Nichol-Kaplan from Corvallis, Oregon, and Mrs Eunice Meixner from Owatonna, MN, and her children Jeanette, Tom, Ken, Karen, Sheila Andy and Mary Meixner, gave us a wealth of personal information. We greatly thank them for their immeasurable help and hospitality while these data were being collected. Mrs Eunice Meixner gathered an amazing collection of records and artefacts relating to Edward Kaplan and she made all of these available for our investigation. Dr Frances Berting, Edward Kaplan's first wife, was also extremely helpful to us as we organized information about those years of his life.

Dr Donald J Cresswell, Dr Wally Reed, Dr Norman Franzen, Professor Ronald Guenther, Professor Diane Meier, and Mrs Karen Meier, shared many valuable personal memories.

Mr Geoff M Somnitz, reference student, and Mr Michael A Dicianna of the Special Collections and Archives Research Center, Professor Sastry G Pantula, Dean of the College of Science and Robert T Smythe, PhD, Professor Emeritus of statistics all from Oregon State University, Corvallis, Oregon, provided valuable information from the Oregon State University archives. We are very grateful to them.

Dr Jennifer Johnson, and Professor János Kollár, mathematicians at Princeton University, and Edward J. Eckert, and Ms Rebecca Nadolny, archivists of Alcatel-Lucent at Bell Labs, Murray Hill NJ, were helpful in locating and making available early manuscripts and reports written by Edward Kaplan. The late Professor John R Nash of Princeton University was so kind as to comment about Kaplan's 1982 book.

Professor Edmund A Gehan, statistician, MD Anderson Cancer Center, Houston TX, provided valuable information on the history of survival analysis.

Ms Amy Claussen and Mr Del Reed, research librarians of the Biomedical Library of the University of Minnesota Medical School in Minneapolis, assisted us in collecting the data for the citation analysis of the 1958 KM published manuscript.

Special thanks for the assistance of Mr Alex Schueller from the Office of then United States Senator Al Franken (Minnesota) in obtaining personnel records (with permission of Edward Kaplan's widow); with Mr Schueller's assistance we also obtained access to records from the Naval Ordnance Laboratory. Copies of Kaplan's personnel file from the Naval Ordnance Laboratory were provided by Ms Cara Moore and Ms Ashley Mattingly, archivists of the United States National Archives in St Louis, Missouri. (Written permission was obtained from Professor Kaplan's widow.)

Professor Sylvia Nasar, Columbia University, New York, New York provided us with daily journal notes from Edward Kaplan which had been previously sent to her by Ms Mae Nichol. This was an extremely valuable group of documents.

Dr Richard Lafrance, MD, retired neurologist at Corvallis Clinic, after written consent from Mae Nichol-Kaplan, reviewed the medical history of Kaplan during the course of the normal pressure hydrocephalus. This proved very valuable for evaluating the last decade of his life.

Mr Lars Groot, medical student at the AMC in Amsterdam, The Netherlands, arranged the fifty Halsted patients into a life-table for further analysis.

The authors are grateful to Claus Pierach, MD for his evaluation of the manuscript and his insightful suggestions. We also express our gratitude to Mrs Irene S Kaplan, the wife of co- author Edward L Kaplan, MD, for her very perceptive suggestions during our investigations and writing for this manuscript.

NOTE: The co-author of this manuscript, Edward Lawrence Kaplan, MD, Professor Emeritus, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, is not related to the subject of this manuscript, Edward Lynn Kaplan, PhD.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

¹ See also: S6: Chronology of the Life of Edward Lynn Kaplan.