The results are in: we are not getting enough sleep
Sleep is not just a quantity issue but also a quality one. Photograph: Getty Images
Over the past four weeks, The Irish Times Sleep Challenge in partnership with Health Founders has highlighted common sleep issues and ways which our sleep can be improved. As part of the Sleep Challenge, we invited you to take part in our nationwide online survey which aimed to take a snapshot of the sleep quality of the Irish.
Almost 1,500 of you between the ages of 13 and 84 took part by self-rating your sleep habits over the past month on The Pittsburgh Sleep Quality Index, an effective instrument used to measure sleep quality. It differentiates “poor” from “good” sleep by measuring subjective sleep quality, the amount of time it takes to fall asleep, sleep duration, percentage time spent asleep in bed, sleep disturbances, use of sleep medication and daytime dysfunction.
The results reflect what the experts tell us; as a nation, we are not getting enough sleep. Only 37.5 per cent of respondents scored as being “good” sleepers, while 62.5 per cent scored as being “poor” sleepers. Despite this, 58.3 per cent of respondents reported that their subjective sleep quality was either very good or fairly good, while 41.7 per cent self-rated their sleep quality as being fairly bad or very bad. This may indicate that some of us are not actually aware that our sleep quality is poorer than it should be.
Every person’s sleep needs are different, but most healthy adults tend to require seven to nine hours per night to function at their best. Our survey indicated that 47.5 per cent of respondents are getting more than the minimum recommended amount of seven hours’ rest each night. However, 30 per cent are getting only six-seven hours, 16.9 per cent are getting five-six hours, while 5.6 per cent reported getting less than five hours’ sleep a night.
Sleep is not just a quantity issue but also a quality one. In order to estimate how efficiently the respondents to our survey sleep, we examined the amount of time they spend asleep (minus any awakenings they may have and how long it takes them to fall asleep) as a ratio of the total time they spend in bed. Experts consider 85 per cent of time spent in bed asleep as normal sleep efficiency, and 38.2 per cent of our sample had a sleep efficiency score of 85 per cent or higher. This means that 61.8 per cent of our sample have sleep efficiency scores that are considered to be sub-standard, or indicative of a poor night’s rest. Some 27.5 per cent of respondents spend 75-84 per cent of their time in bed actually asleep, while 16 per cent are asleep for only 65-75 per cent of that time and 18.3 per cent spend less than 65 per cent of their total time in bed asleep.
Not getting enough sleep can have a serious impact on our daytime functioning. Only 63.6 per cent of study respondents reported having no trouble staying awake while driving, eating meals or engaging in social activity in the past month. Some 24.9 per cent of people estimated that such difficulty staying awake occurred less than once a week. However, 8.5 per cent reported trouble staying awake once or twice a week, while 3 per cent of respondents reported difficulty staying awake during such activities more than three times a week. Furthermore, 84.2 per cent of respondents reported having some problems with keeping up enough enthusiasm to get things done in the past month.
We also know that notable changes occur in our sleep structure and patterns as we get older and this can make getting a good night’s sleep harder to come by. It is perhaps not surprising then, that the survey results highlighted a significant relationship between sleep quality scores and age, with older respondents generally reporting poorer sleep quality than their younger counterparts.
There are a myriad of factors that can affect the rest we get. Although it was beyond the scope of this survey to examine all potential causes of poor sleep quality, a number of factors were accounted for. Within this survey, stress, racing thoughts and the presence of young children or a bed partner emerged as the most common barriers to getting a good night’s sleep.
The Pittsburgh Sleep Quality Index is © 1989, University of Pittsburgh. All rights reserved. Developed by Buysse,DJ, Reynolds,CF, Monk,TH, Berman,SR and Kupfer,DJ of the University of Pittsburgh using National Institute of Mental Health Funding. Buysse DJ, Reynolds CF, Monk TH, Berman SR, Kupfer DJ: Psychiatry Research, 28:193-213, 1989.