Obsidian | Level 7

## Cumulative Residual Plots (CURE plots)

Hello Everyone,

I have been working on generating regression models to fit collision data. The general model approach is to use Negative Binomial Regression, using a log link function. The model could have been fitted using PROC GENMOD, I understand that in that code using ODS Graphics it would be possible to CURE Plots. However, this would be at a cost of assuming a fixed dispersion parameter. As such NL MIXED was the way to go as seen below.

Is there a way I can use NL MIXED to get my cure plots, or do I need to set the model up in PROC GENMOD?

``````libname db 'V:\data';/* General Model Form: TOT=exp(alpha1)(AADT)^beta1 (Length)^beta2 (IRI)^beta3 Dispersion (k)=exp(alpha2)(length)^beta4 */proc nlmixed data=db.dir5lane2;parms alpha1 1 beta1 1 beta2 1 beta3 1 alpha2 1 beta4 1  ;
eta = alpha1 + beta1*logaadtn + beta2*loglength + beta3*logiri;
lambda = exp(eta);
eta_k = alpha2+beta4*loglength;
k = exp(eta_k);
loglike = (lgamma(TOT+(1/k)) - lgamma(TOT+1) - lgamma(1/k) +
TOT*log(k*lambda) - (TOT+(1/k))*log(1+k*lambda));
model TOT ~ general(loglike);
run;``````

Any suggestion are appreciated,

Iliya

3 REPLIES 3
Tourmaline | Level 20

## Re: Cumulative Residual Plots (CURE plots)

Move question to " Statistical Procedures" to increase the chances of a reply.
SAS Super FREQ

## Re: Cumulative Residual Plots (CURE plots)

By default, GENMOD estimates the negative binomial dispersion parameter by maximum likelihood - it is not fixed.

Obsidian | Level 7

## Re: Cumulative Residual Plots (CURE plots)

Did you come up with a solution yet for CURE plot in Proc NLMIXED? Please share if you did.

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