topic Kappa coefficient in SAS Procedures

Kappa coefficient

darb — Thu, 01 Feb 2018 17:33:17 GMT

So currently I am assessing agreement between two evaluators. They are assessing disease response and the table would like below:

Evaluater 2 CR CRc CRi PR SD PD

Evaluater 1

CRc

CRi

To calculate a weighted Kappa is assigned an Ordinal value to each response: 1, 2, 3, 4, 5, 6. Which sas that uses the following weights as default: 1.00, 0.8, 0.6, 0.4, 0.2.

However, I would really like for CRc and CRi to have the same weights for distance from CR. Does anyone know how I should reorder the ordinal values if even possible, my issue is that they can't have the same ordinal value --- is the only way to combine CRc & CRi? I don't know if that would be clinically meaningful.

Re: Kappa coefficient

ballardw — Thu, 01 Feb 2018 18:23:53 GMT

What are you basing this statement on: "Which sas that uses the following weights as default: 1.00, 0.8, 0.6, 0.4, 0.2."

What does your current data actually look like is it something like:

Evaluator Value RecordID

There are a number of procedures that will do Kappa coefficients or analysis but we kind of need to know what the raw data looks like to make recommendations.

Re: Kappa coefficient

darb — Thu, 01 Feb 2018 18:36:05 GMT

I can print the weights Sas is using:

ods html;
proc freq data = test5 ;
table xrorres1*bestresp1/agree printkwts ;
test kappa;
weight count;
run;
ods html close;

Data looks like this:

xrorres1 bestresp1 count

CR CR 5

CR CRi 3

CR CRc 2

CR PR 0

CR SD 0

CRi PD 0

etc etc etc