QOL data and routine clinical data such as laboratory data, whether used in clinical practice or research, can be viewed by clinicians in the same way. Both provide important patient-related information using instruments which are reliable and valid. Both require that the clinician or researcher understand how to utilize and interpret the data and gain comfort with doing so through experience. It is through this repeated usage of QOL data that clinicians will, hopefully, come to accept QOL data as a routine and invaluable part of their practice and view it just as they view other clinical data. Whether it is a clinician looking at QOL data or laboratory data for the first time, or a clinical researcher including QOL data in a clinical trial for the first time, training, repetitive use, and experience is necessary to feel comfortable with integrating the data to recommend an appropriate clinical action or to capture the meaningful effect.