Introduction: The Kaplan Meier method (or the Kaplan Meier Product Limit Estimator) is a a nonparametric (actuarial) technique for estimating time-related events (the survivorship function). 1 Ordinarily it is used to analyze death as an outcome. It may be used effectively to analyze time to an endpoint, such as remission. 	Kaplan-Meier

The Kaplan-Meier method is a nonparametric (actuarial) technique for estimating time-related events (the survivorship function). 1 Ordinarily it is used to analyze death as an outcome. It may be used effectively to analyze time to an endpoint, such as remission.

It is a univariate analysis and is an appropriate starting technique. It estimates the probability of the proportion of individuals in remission at a particular time, starting from the initiation of active date (time zero), is especially applicable when length of follow-up varies from customer to customer, and takes into account those customer lost to follow-up or not yet in remission at end of study (censored customers, assuming the censoring is non-informative). It is therefore the instrument of choice in evaluating remissions following loosing a customer. Since the estimated survival distribution for the cohort study has some degree of uncertainty, 95% confidence intervals may be calculated for each survival probability on the “estimated” curve.

A variety of tests (log-rank, Wilcoxan and Gehen) may be used to compare two or more Kaplan-Meier “curves” under certain well-defined circumstances. Median remission time (the time when 50% of the cohort has reached remission), as well as quantities such as three, five, and ten year probability of remission, can also be generated from the Kaplan-Meier analysis, provided there has been sufficient follow-up of subjects.

Need: The K-M test is one of the most commonly used statistical tests in the medical field in almost all clinical branches. It allows calculation of survival estimates. At present several commercial software packages allow the use the this test but they are expensive. The free and OS alternative is R, sadly it is CLI based and difficult to use by the medical professionals who have limited computing knowledge. To my current knowledge there are no free alternatives for this test elsewhere. Gnumeric can provide this statistical test in the statistical plugins list for ease of use of this software by the medical profession. I am sure the acceptance for this software will increase remarkably if this statistical test is implemented.

What the test does:
Please see a nice demo on the following website:
http://www.medcalc.be/manual/kaplan-meier.php

The data is presented in a columnar format in which the user has the first column for the time for the event to occur (e.g. disease recurrence). The second column contains the descriptor for the event (e.g. disease recurrence = 1 , disease free = 0) and an optional 3rd column containing the grouping variable (eg male = 1 , female =2 and so on). The test consists of two parts - a mathematical equation which derives the survival times based upon the time of "censoring" and a graphical component which shows the curves typically in a step ladder pattern.

How I can help:
I cant help with the coding part but I can help with the equations and I have several examples of the SPSS output for various scenarios that I can share which include the calculations and the graph.

I can be contacted at drsantam (at the rate of) gmail dot com