A medical diagnosis of systemic lupus erythematosus (according to current clinical classification criteria);
Both sexes;
Clinically stable condition during the previous 3 months; and
Provision of written informed consent.
You may not be if
Individuals whose usual occupation involves night or rotating shift work;
A previous diagnosis of a primary sleep disorder receiving specific treatment (e.g., severe obstructive sleep apnea treated with CPAP, narcolepsy, or other central sleep disorders); and
Psychiatric or cognitive impairment that may prevent or substantially limit the accurate completion of the questionnaires
