Time to wake up: individualising the approach to sleep promotion interventions.

Sleep is fundamental to normal physiological and cognitive function. Sleep promotion strategies have been used extensively in clinical settings, as a treatment for various ailments (ie, insomnia). However, sleep problems are prevalent outside these realms, with 56% of American, 31% of Western European and 29% of Japanese people suffering from sleep problems the previous year. The global public health concern over sleep has increased the demand for sleep promotion interventions, but the efficacy of these strategies is unclear in otherwise healthy and athletic populations. One possibility is due to the presentation and analysis of grouped data, despite sleep naturally being a highly variable and inherent trait. We argue the case for (1) presenting sleep data at the individual level and (2) individualising sleep promotion interventions.