Abstract
COVID-19 pandemic confinement caused changes in families and children's routines worldwide. Studies conducted at the beginning of the pandemic have examined the harmful effects of these changes on mental health, including sleep disturbances. As sleep is essential for optimal childhood development, this study was designed to determine preschool-aged (3-6 years old) children's sleep parameters and mental well-being during the COVID-19 pandemic in Mexico. Using a cross-sectional design, a survey was applied to parents of preschool children, inquiring about their children's confinement status, routine changes, and electronics use. The parents responded to the Children's Sleep Habits Questionnaire and the Strengths and Difficulties Questionnaire to assess children's sleep and mental well-being. To provide objective sleep data, the children wore wrist actigraphy for seven days. Fifty-one participants completed the assessment. The children's mean age was 5.2 years, and the prevalence of sleep disturbances was 68.6%. The use of electronic tablets in the bedroom near bedtime and symptoms of mental health deterioration (i.e., emotional distress and behavioral difficulties) were associated with sleep disturbances and their severity. The COVID-19 pandemic's confinement-related routine changes greatly impacted preschool children's sleep and well-being. We recommend establishing age-tailored interventions to manage children at higher risk.