Posts Tagged ‘ proc phreg ’

Example 9.7: New stuff in SAS 9.3– Frailty models

September 27, 2011
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Example 9.7: New stuff in SAS 9.3– Frailty models

Shared frailty models are a way of allowing correlated observations into proportional hazards models. Briefly, instead of l_i(t) = l_0(t)e^(x_iB), we allow l_ij(t) = l_0(t)e^(x_ijB + g_i), where observations j are in clusters i, g_i is typically norma...

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Example 7.42: Testing the proportionality assumption

June 21, 2010
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Example 7.42: Testing the proportionality assumption

In addition to the non-parametric tools discussed in recent entries, it's common to use proportional hazards regression, (section 4.3.1) also called Cox regression, in evaluating survival data.It's important in such models to test the proportionality a...

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