topic Importing Data for a Chi Square Test in SAS Programming https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412411#M279839 <P>So for a problem, I am comparing Positron Emission Tomography (PET) and Computed Tomography (CT) to Magnetic Resonance Imaging (MRI). I am ultimately asked if there is a difference in accuracy between PETCT and MRI, which one would be better and what the degree of association between the two methods is. Because of the last part about association, I know I need to run a Chi-Square Test. But first, I can't get my data imported correctly.</P><P>There are 50 subjects and the data looks like this:</P><P>Subject MRI PET-CT<BR />1 Correct Correct<BR />2 Correct Correct<BR />3 Correct Correct<BR />4 Correct Correct<BR />5 Correct Correct<BR />6 Correct Correct<BR />7 Correct Correct<BR />8 Correct Correct<BR />9 Correct Correct<BR />10 Correct Correct<BR />11 Correct Correct<BR />12 Correct Correct<BR />13 Correct Correct<BR />14 Correct Correct<BR />15 Correct Correct<BR />16 Correct Correct<BR />17 Correct Correct<BR />18 Correct Correct<BR />19 Correct Correct<BR />20 Correct Correct<BR />21 Correct Correct<BR />22 Correct Correct<BR />23 Correct Correct<BR />24 Correct Correct<BR />25 Correct Correct<BR />26 Correct Correct<BR />27 Correct Correct<BR />28 Correct Correct<BR />29 Correct Correct<BR />30 Correct Correct<BR />31 Correct Correct<BR />32 Correct Correct<BR />33 Correct Correct<BR />34 Correct Correct<BR />35 Correct Correct<BR />36 Correct Correct<BR />37 Correct Incorrect<BR />38 Incorrect Correct<BR />39 Incorrect Correct<BR />40 Incorrect Correct<BR />41 Incorrect Correct<BR />42 Incorrect Correct<BR />43 Incorrect Correct<BR />44 Incorrect Correct<BR />45 Incorrect Correct<BR />46 Incorrect Correct<BR />47 Incorrect Correct<BR />48 Incorrect Correct<BR />49 Incorrect Incorrect<BR />50 Incorrect Incorrect</P><P>&nbsp;</P><P>I don't know how to get the data into a table that will allow me the run a chi-square. Any tips?</P> Fri, 10 Nov 2017 16:18:41 GMT trash 2017-11-10T16:18:41Z Importing Data for a Chi Square Test https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412411#M279839 <P>So for a problem, I am comparing Positron Emission Tomography (PET) and Computed Tomography (CT) to Magnetic Resonance Imaging (MRI). I am ultimately asked if there is a difference in accuracy between PETCT and MRI, which one would be better and what the degree of association between the two methods is. Because of the last part about association, I know I need to run a Chi-Square Test. But first, I can't get my data imported correctly.</P><P>There are 50 subjects and the data looks like this:</P><P>Subject MRI PET-CT<BR />1 Correct Correct<BR />2 Correct Correct<BR />3 Correct Correct<BR />4 Correct Correct<BR />5 Correct Correct<BR />6 Correct Correct<BR />7 Correct Correct<BR />8 Correct Correct<BR />9 Correct Correct<BR />10 Correct Correct<BR />11 Correct Correct<BR />12 Correct Correct<BR />13 Correct Correct<BR />14 Correct Correct<BR />15 Correct Correct<BR />16 Correct Correct<BR />17 Correct Correct<BR />18 Correct Correct<BR />19 Correct Correct<BR />20 Correct Correct<BR />21 Correct Correct<BR />22 Correct Correct<BR />23 Correct Correct<BR />24 Correct Correct<BR />25 Correct Correct<BR />26 Correct Correct<BR />27 Correct Correct<BR />28 Correct Correct<BR />29 Correct Correct<BR />30 Correct Correct<BR />31 Correct Correct<BR />32 Correct Correct<BR />33 Correct Correct<BR />34 Correct Correct<BR />35 Correct Correct<BR />36 Correct Correct<BR />37 Correct Incorrect<BR />38 Incorrect Correct<BR />39 Incorrect Correct<BR />40 Incorrect Correct<BR />41 Incorrect Correct<BR />42 Incorrect Correct<BR />43 Incorrect Correct<BR />44 Incorrect Correct<BR />45 Incorrect Correct<BR />46 Incorrect Correct<BR />47 Incorrect Correct<BR />48 Incorrect Correct<BR />49 Incorrect Incorrect<BR />50 Incorrect Incorrect</P><P>&nbsp;</P><P>I don't know how to get the data into a table that will allow me the run a chi-square. Any tips?</P> Fri, 10 Nov 2017 16:18:41 GMT https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412411#M279839 trash 2017-11-10T16:18:41Z Re: Importing Data for a Chi Square Test https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412415#M279840 <PRE>/* UNTESTED CODE */ proc freq data=have; tables MRI*PETCT/chisq; run;</PRE> Fri, 10 Nov 2017 16:23:51 GMT https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412415#M279840 PaigeMiller 2017-11-10T16:23:51Z Re: Importing Data for a Chi Square Test https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412420#M279841 <P>In addition to Chi Squared you're likely going to want to calculate the specificity and sensitivity.&nbsp;</P> <P>&nbsp;</P> <P><A href="https://en.wikipedia.org/wiki/Sensitivity_and_specificity" target="_blank">https://en.wikipedia.org/wiki/Sensitivity_and_specificity</A></P> Fri, 10 Nov 2017 16:40:07 GMT https://communities.sas.com/t5/SAS-Programming/Importing-Data-for-a-Chi-Square-Test/m-p/412420#M279841 Reeza 2017-11-10T16:40:07Z