Final answer:
Kaplan-Meier curves estimate the survival function from lifetime data and can handle censored observations. They are pivotal in visualizing and comparing the survival rates over time between different populations in medical research.
Step-by-step explanation:
Kaplan-Meier curves, also known as the product-limit estimator, are used in medical research to estimate the survival function from lifetime data. In particular, these curves are capable of incorporating censored data, which is data that represents incomplete observations, such as patients dropping out of a study or the study period ending before an event occurs. The Kaplan-Meier curve provides a way of visualizing how certain factors, such as treatment methods or risk factors, affect the survival rate of a population over time. The x-axis typically represents time, while the y-axis represents the proportion of individuals surviving.
The effectiveness of Kaplan-Meier curves lies in their ability to show how the probability of surviving past a certain point in time decreases. It can also compare the survival times of different groups, which is essential in clinical trials. By analyzing the shape and the slope of these curves, researchers can assess the risk and determine the efficacy of new treatments or understand the prognosis of certain diseases.