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Survivorship Analysis

What's wrong with calculating the mean survival time and its confidence interval (Cl)? This approach is rarely useful. One problem is that you can't calculate the mean survival time until you know the survival time for each patient, which means you can't analyze the data until the last patient has died. Another problem is that survival times are unlikely to follow a Gaussian distribution. For these and other reasons, special methods must be used for analysis of survival data.


Survival curves plot percent survival as a function of time. Figure1 shows a simple survival curve. Fifteen patients were followed for 36 months. Nine patients died at known times, and six were still alive at the end of the study.

Figure 6.1. Simple survival curve.

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Chi-Squared Test
Choosing a Statistical Test
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Statistics in Orthopaedics
Survivorship Analysis
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