A study carried out in Finland over decades found that more than 70 percent of working-age Finnish adults regularly get a good night's rest. However, as people age, sleep quality tends to decline, according to researchers who studied the sleeping habits and health histories of nearly 5,000 Finns over a 36-year period.
The study, carried out by the Finnish Institute of Occupational Health (FIOH) and the University of Helsinki, asked thousands of participants how they slept and perceived the quality of their sleep during the course of the long-term survey.
The institute's chief physician, Christer Hublin, who co-authored the study, said that even though temporary sleeping difficulties appear to be increasing, most of the study subjects actually reported that they tended to sleep pretty well.
"The findings of the research are good news, considering how many links there are between sleep and health," Hublin said.
The sleep study subjects were born between 1945 and 1957 and were around 24 years old when they entered the study.
Over decades, the subjects were answered questions about their sleep quality in surveys carried out in 1975, 1981, 1990 and 2011.
Most said they sleep well
Only a small portion of the study subjects suffered from permanent poor sleep quality. Just half of a percent of participants said they slept poorly or fairly poorly every time the questions were posed.
However, a much larger portion - an overwhelming majority of 71 percent of the working-age subjects - said they slept well or fairly well each time they answered the periodical questionnaires.
The Finnish sleep quality study is different from others in that it followed the same subjects over the entire period of the survey, Hublin noted.
Previous sleep studies tended to follow different people using different recording methods.
"In this way the results of [our] research is more stable," Hublin said.
Sleep, age and health
The researchers also wanted to explore how people viewed their quality of sleep in general over an extended period of time, while other studies on the topic of sleeplessness have generally focused on insomnia symptoms over the previous month.
The study also examined sleep quality perceptions in relation to age and health issues. Participants who were most sleep-deprived also often suffered from other health issues.
The research also saw clear connections between symptoms of depression and sleep problems.
According to Professor Jaakko Kaprio of the University of Helsinki, occasional, temporary bouts of sleeplessness are quite common among Finns and the condition can arise for a short period in people who overall feel they generally sleep well.
However, not everyone does get enough good, restful sleep and a significant segment of the population said they sleep pretty poorly.
Hublin explains that chronic insomnia is a medical condition, advising sufferers of the affliction to reach out to physicians for help.
The study was published in the Journal of Sleep Research.