u/madsena
Separating sleep duration from timing in cognitive performance studies.
PMID 42284965 explicitly considers sleep duration alongside a time-restricted eating window and CLOCK variants. The key measurement question is whether the eating window and sleep were represented only by duration, or also by clock timing and their relative phase.
Suppose cognitive performance is associated with sleep duration, but testing occurs at different clock times across participants. Which measurements would let us assess whether the association instead reflects circadian phase or time awake at testing? Clock time alone may be insufficient if chronotype, weekday versus weekend conditions, and the interval since waking were not recorded.
The reported association between social jet lag and incident cardiovascular disease is framed as independent of sleep duration. Interpreting that separation requires the timing definition, sleep-duration measurement window, and adjustment model, especially whether weekday and weekend test conditions were recorded.
