Such data is usually not necessary for 510(k) applications, but if a 510(k) product has a significant use-related problem, FDA will ask to see human factors testing data, she added. And if such testing was never done, a firm could get in serious trouble with the agency. "FDA wants you to show what you did in terms of figuring out what predictable things could go wrong," she said. "`Nothing' is the wrong answer." Clinical trial data is not a substitute for human factors data, nor is a standard Failure Mode and Effects Analysis, nor especially is a labeling comprehension review, she stressed.