One way to evaluate any study of fatigue is to ask yourself how they looked at activity levels. Did they take variation into account. If they didnt, time to put on your skeptic hat.....This is an example of how not to do it.... Originally Posted by glenp 4. The following items are about activities you might do during a typical day. Does your health now limit you in these activities? If so, how much? (check one on each line) ACTIVITIES Yes, Limited A Lot Yes, Limited A Little No, Not Limited At All (many activities then listed) TYPICAL DAY ????? Any study of CFS that asks patients questions like this ignores the periodicity of the disease will produce confusing results....This can't be stressed enough.....You can be good one day, and bedridden the next, variations can exist between days, weeks, months or even years. This has been shown in this forum over and over again......... Any analysis based on questions that ignore variation of fatigue / exhaustion levels and then attempts to to correlate these levels other phenomenon will be worthless....or worse.... This is Survey 101, The waxing and waning of the disease, has to be taken to account in any research that looks at activity levels. Whoever is writing these questions doesnt seems to have talked to many patients with CFS and or is missing a basic aspect of this syndrome. It is something that should be delt with in every study that purports to study CFS.