|
I have some questions on running a non-inferiority study outside of clinical
trials.
First, I am having trouble determining a cut-score for the study I am
running and cannot find direction in the literature other than the
references to set the null proportion difference to -.10 or in a few cases
-.05. I am struggling to determine the range of meaningful difference.
Second, I am measuring venue and whether collecting data in an alternate
venues is "not appreciably worse" than the traditional standard for four
different variables. For example, I measured the number of participant words
per idea. Thus my data is continuous, and I am confused as to how to code
this. Here is a truncated version of my data with the variables of interest
being venue and wordidea:
data noninf;
input subject $ gender $ state $ group $ venue $ ideas words wordidea;
cards;
1 2 1 2 1 4 82 20.50
2 2 1 2 1 6 115 19.17
3 2 1 2 1 3 37 12.33
4 2 1 2 1 8 101 12.63
16 2 2 3 2 18 2217 123.17
30 1 3 1 3 6 485 80.83
;
run;
I tried reformatting my data:
data noninf;
input v1_wi v2_wi;
cards;
20.50 123.17 19.17 80.83; /*with more cards*/
run;
proc ttest data=noninf dist=normal tost(-10, 10);
paired v1_wi*v2_wi;
run;
with these results:
The TTEST Procedure
Difference: v1_wi - v2_wi
N Mean Std Dev Std Err Minimum Maximum
9 -26.2180 40.9299 13.6433 -113.4 26.7048
Mean 95% CL Mean Std Dev 95% CL Std Dev
-26.2180 -57.6795 5.2434 40.9299 27.6464 78.4122
TOST Level 0.05 Equivalence Analysis
Lower Upper
Mean Bound 90% CL Mean Bound Assessment
-26.2180 -10 > -51.5884 -0.8477 < 10 Not equivalent
Test Null DF t Value P-Value
Upper -10 8 -1.19 0.8657
Lower 10 8 -2.65 0.0145
Overall 0.8657
Any help would be appreciated.
Thank you,
June
|