A factor replication of the Sleep-Wake Activity Inventory (SWAI) in a Mexican population.

The purpose of this study was to describe the factor structure of the Sleep-Wake Activity Inventory (SWAI) in a Mexican population. In a sample of 722 Mexican college students, we replicated five of the six factors originally described in the SWAI. Retained factors included: excessive daytime sleepiness (similarity coefficient of 0.735), psychic distress (0.609), social desirability (0.638), individual's ability to relax (0.864), and nocturnal sleep (0.660). These results confirm the factor structure and extend the possible utility of the SWAI in a siesta culture.