Researchers have shown that there is a likeness in the meaning of sleep quality between insomniacs and normal sleepers, by finding that both insomnia patients and normal sleepers define sleep quality by tiredness upon waking and throughout the day, feeling rested and restored upon waking, and the number of awakenings they experienced in the night.
The study also found that people with insomnia have more requirements for judging sleep to be of good quality.
"Good sleep quality is associated with a wide range of positive outcomes such as better health, less daytime sleepiness, greater well-being and better psychological functioning," said Allison G. Harvey, PhD, of the University of California at Berkeley, lead author of the study.
"Moreover, poor sleep quality is one of the defining features of chronic insomnia. So it is surprising that there is minimal systematic research devoted to how humans arrive at their subjective sense of whether they had a good or poor nights sleep," he added.
In this study, the team used a range of methods to compare the sleep quality judgments of insomnia patients and good sleepers.
They found that tiredness upon waking and throughout the day were most consistently associated with sleep quality judgments, signifying the importance of the recent shift in the field to study daytime variables.
Further, the results showed that individuals with insomnia appear to have more requirements to be met before they feel have experienced a night of good sleep quality.
The study focused on 25 individuals with insomnia and 28 normal sleepers, whose descriptions of good and poor sleep quality nights were analysed and recorded.
Insomnia is a classification of sleep disorders in which a person has trouble falling asleep, staying asleep or waking up too early. These disorders may also be defined by an overall poor quality of sleep.
The study appears in the March 1 issue of the journal Sleep.