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Justin12
Calcite | Level 5
drugplacebo
105160
110140
108150
112 
 136
116146
112140
108 
 150
114138
 148
 150
  
 156
 152

 

I have this data that compares blood pressures. The placebo column is patients normal blood pressures and the drug column has their pressures after the drug is administered. I am trying to use a certain PROC statement to determine statistically whether the drug does lower pressures. So after I imported the data into SAS named 'blood' and I am running a simple t-test.

 

proc ttest data=blood;

paired drug*placebo;

run;

 

Does this make sense or should I use proq freq with the chisq option?

 

4 REPLIES 4
ballardw
Super User

If you research question is about "mean difference of measurement" then you ttest looks right though I hope you have more records.

Do take note than any subject that does not have both measurements will be excluded from the calculations.

 

If the same subject appears multiple times then you are into a "repeated measures" environment and ttest may not be appropriate.

Reeza
Super User

For a test like this you should run a paired test ideally, but do you have enough data? The documentation for PROC TTEST has an example I believe.

 


@Justin12 wrote:
drug placebo
105 160
110 140
108 150
112  
  136
116 146
112 140
108  
  150
114 138
  148
  150
   
  156
  152

 

I have this data that compares blood pressures. The placebo column is patients normal blood pressures and the drug column has their pressures after the drug is administered. I am trying to use a certain PROC statement to determine statistically whether the drug does lower pressures. So after I imported the data into SAS named 'blood' and I am running a simple t-test.

 

proc ttest data=blood;

paired drug*placebo;

run;

 

Does this make sense or should I use proq freq with the chisq option?

 


 

Justin12
Calcite | Level 5

Ok, thanks. I do have more data, the above was just a small sample of it.

Reeza
Super User

Then a T-Test is the appropriate statistical test in this case, and a paired t-test. You should always make a graph too, a slope graph for all users and a histogram of the differences would be my suggestions. 

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