Statistics2013 Poster. Kaplan-Meier Estimator. Bo Huang, Ching-Ray Yu and Christy Chuang-Stein Pfizer Inc. Statistics Saves Lives. The History of the Kaplan-Meier Estimator.
Bo Huang, Ching-Ray Yu and Christy Chuang-Stein
Statistics Saves Lives
In a paper published in the Journal of the American Statistical Association in June 1958, Edward Kaplan and Paul Meier put forth a new, efficient method for estimating patient survival rates, taking into account the fact that some patients may have died during a research trial while others will survive beyond the end of the trial. The method, called the Kaplan-Meier estimator (also known as the product limit estimator), is based on a mathematical formula using information from those who have died and those who have survived to estimate the proportion of patients alive at any point during the trial. The estimator is plotted over time. The resulting curve is called the Kaplan-Meier curve, which is a series of horizontal steps of declining magnitude that, when a large enough sample is taken, approaches the true survival function for that population.
According to Current Contents (1983), the seminal paper by Kaplan and Meier began in 1952 when Paul Meier, then at Johns Hopkins University, encountered Greenwood’s paper on the duration of cancer. A year later, while at Bell Laboratories, Kaplan became interested in the lifetimes of vacuum tubes in the repeaters in telephone cables buried in the ocean. Kaplan and Meier worked independently and submitted their respective work to the Journal of American Statistical Association. The journal encouraged them to submit a joint paper. Kaplan and Meier spent the next 4 years to resolve differences in their approaches and published a method that ultimately became the standard nonparametric approach for analyzing time to event data with censored observations.
Example 1: KM curves of overall survival of an experimental drug vs the standard chemotherapy in a randomized phase III study in patients with advanced melanoma
Source: Marshall, Ribas and Huang, ASCO, 2010
Example 2: KM curve of progression-free survival in a randomized placebo-controlled phase III trial of sunitinib in patients with advanced pancreatic neuroendocrine tumors
Source: Raymond et al., NEJM, 2011
Publications refer to research papers related to the Kaplan-Meier method.
Citations refer to all the medical and statistical papers that cite the 1958 seminal paper
Publications and citations are on different scales in the double-axis figure
Source: Microsoft academic research
The KM curve has become the standard tool used by medical researchers for determining the duration of survival in thousands of studies, ranging from cancer to AIDS to cardiovascular disease to diabetes, to name just a few -- New York Times (2011)
The KM estimate was a very, very important advance. It seems so elementary now -- Washington Post (2011)
Paul Meier’s work and the KM analysis have been responsible for saving millions of lives
--- The Significance Magazine (2011)
The KM estimator is used ubiquitously in medical studies to estimate and depict the fraction of patients living for a certain amount of time after treatment. It has since been applied to data from clinical trials of therapies for every disease from cancer to cardiology to concussion
-- Science Life (2011)