Is it O.K. to change the time frame used in the FACIT questionnaires?
Most of our data are available using a time frame of the past 7 days (one week). So, changing the time frame risks ones ability to comfortably compare results to most of our available data. However, we and others have studied this and found little difference between responses to the same question using one time frame versus another. Therefore, the questions themselves tend to retain their validity and value, but the ability to compare to most available data is potentially limited.
