21 CFR 820.250 (Statistical Techniques) uses the term "valid statistical rationale".
I'm wondering if this necessarily means being able to back sampling plans with statistical formulae? ...or can the "statistical rationale" be indirect, say, from published research?
For example, Faulkner (Behavior Research Methods, Instruments, & Computers 2003, 35 (3), 379-383), conducts a study examining the correlation between number of subjects in a usability study, and the number of problems identified.
Can citing a study like this be an acceptable basis (according to FDA) for developing a human-factors study sampling plan? The FDA themselves cite it in their "Draft Guidance for Industry and Food and Drug Administration Staff - Applying Human Factors and Usability Engineering to Optimize Medical Device Design".
However, my concern is that, if scrutinized by the FDA, such a rationale would be difficult to argue, given that it is based on analysis of data gathered from a single study, and the author's conclusions. ...and not on established statistical methods...
I'm wondering if this necessarily means being able to back sampling plans with statistical formulae? ...or can the "statistical rationale" be indirect, say, from published research?
For example, Faulkner (Behavior Research Methods, Instruments, & Computers 2003, 35 (3), 379-383), conducts a study examining the correlation between number of subjects in a usability study, and the number of problems identified.
Can citing a study like this be an acceptable basis (according to FDA) for developing a human-factors study sampling plan? The FDA themselves cite it in their "Draft Guidance for Industry and Food and Drug Administration Staff - Applying Human Factors and Usability Engineering to Optimize Medical Device Design".
However, my concern is that, if scrutinized by the FDA, such a rationale would be difficult to argue, given that it is based on analysis of data gathered from a single study, and the author's conclusions. ...and not on established statistical methods...