- Sleep Quality
- Better in assessing sleep than sleep quantity
- Obtaining good quality sleep is very important
- Association between good quality sleep and better general health
Studies on sleep quality started later than those on sleep quantity. Actually, it began in 1989 when Ford and Kamerow revealed that insomnia increases risk of psychiatric disorders. Since then, its importance has been stressed repeatedly. According to Linhao Zhang, lead author of the study and a recent doctoral graduate of the College of Family and Consumer Sciences, "It's not just about how long you slept. It's how well did you sleep? Did you take a long time to fall asleep? Did you wake up in the middle of the night?" The quote reflects on how significant sleep quality is viewed in more recent studies.
A nationwide research team on the quality of sleep has made a claim along the same line, stating that sleep quality is a better indicator than sleep quantity in assessing sleep. Restfulness obtained through sleep is a useful index for assessing sleep quality. As a result, researchers recommend individuals to pay more attention to obtaining good quality sleep. Not enough studies have been conducted on the relationships between sleep quality and health or disorders in children and adolescents. Despite this, we are aware that there is an association between good quality sleep and better general health. Authors of a research study also identified factors affecting sleep quality of children and adolescents. They "found that evening circadian preference, mobile phone and Internet use, number of other activities (music, television, gaming console, sport, etc.) after 21:00, late turning off time, and number of devices in the bedroom had an unfavorable effect on sleep quality."
Javaheri et al.'s investigation on association between sleep variables (quantity and quality) and blood pressure in adolescents aged 13-16 revealed valuable insights on the effect of lack of sleep and health. In this research, short sleep duration (6.5hr or less) and low sleep efficiency (85% or less) were used for sleep variables. Odds for prehypertension (Blood pressure being at or above 90% of the age, gender, and height standardized value) was increased 4.5-fold among participants with low sleep efficiency & 2.8-fold in those with short sleep duration. Those with poor sleep quality (low sleep efficiency) found to have systolic blood pressure 4.0mmHg higher than other adolescents.