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Fig. 2 | BMC Medical Research Methodology

Fig. 2

From: A non-linear optimisation method to extract summary statistics from Kaplan-Meier survival plots using the published P value

Fig. 2

Determining the number of points to calculate an optimal solution using the nlopt method for an exact P value. The KM survival probabilities were extracted from three published studies. A set number of points, ranging from 5 to 50 (a, c) and 5–30 (b), were extracted from the KM survival probabilities and these points used to calculate ln (HR) (middle panel) and var. ln (HR) (right panel) using the nlopt method with an exact P value. One hundred Monte Carlo simulations were carried out and the mean and associated standard deviation plotted. The red, dashed horizontal line represents the actual value from the published study

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BMC Medical Research Methodology

ISSN: 1471-2288

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