BookmarkSubscribeRSS Feed
skavyasindhu
Fluorite | Level 6

Hi everyone,

 

I am doing a negative binomial model and have a question predicted counts.

Outcome = #events/person-years

primary predictor - year (calender years from 2009 to 2018)

model statement: 

model outcome = year age gender race/ offset=log_personyears dist=nb link=log;

 

I am trying to calculate expected counts per 1000 person years. How can I change the offset to predict 1000 person years rather than 1 person year?

 

Thanks.

1 REPLY 1
SteveDenham
Jade | Level 19

 

When you calculate log_personyears in your DATA step, I assume you do something like:

 

log_personyears = log (personyears);

 

So if you wish the offset to be per 1000 personyears, change that calculation to

 

log_thoupersonyears = log(1000*personyers);

 

Let us know if that does what you need.

 

SteveDenham

hackathon24-white-horiz.png

The 2025 SAS Hackathon has begun!

It's finally time to hack! Remember to visit the SAS Hacker's Hub regularly for news and updates.

Latest Updates

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 1 reply
  • 786 views
  • 0 likes
  • 2 in conversation