Daytime Sleepiness

Last edited | 10/22/2008

Inconsistent definitions (e.g., getting too much sleep, falling asleep in the day) have contributed to this variable prevalence rate.

The etiology of daytime sleepiness involves various sleep disorders such as:

•  obstructive sleep apnea syndrome,

•  heavy snoring and

•  narcolepsy.

However, the presence of daytime sleepiness can be explained by other disorders, such as an insufficient sleep syndrome and/or poor sleep hygiene.

Sleepiness is involved in approximately 16% of motor vehicle accidents in England.

Moreover, it has been suggested that half of the work-related accidents and a quarter of home-based accidents are caused by sleepiness.

Research

In 1994, a representative sample of the non-institutionalized UK population aged 15 years and over were interviewed by telephone using the Sleep-EVAL system designed to facilitate surveys of this type.

4972 interviews were completed (acceptance rate: 79.6%).

Results

Subjects were classified into three groups based on the severity of their daytime sleepiness:

• Severe daytime sleepiness was reported in 5.5% (95% Confidence Intervals (CI) 4.9% to 6.1%) of the sample.
  Associated factors with severe daytime sleepiness included:
      women,
      middle age, napping,
      insomnia symptoms,
      high daily caffeine consumption,
      breathing pauses or leg pain in sleep,
      DSM-IV depressive disorder,
      falling asleep while reading or watching television, and
      motor vehicle accidents or accidents involving use of machinery.

• Moderate daytime sleepiness in 15.2% (95% CI: 14.2% to 16.2%) of the sample.
  It was associated with women, napping, insomnia symptoms, arthritis or heart disease and gross motor movements during sleep.

Daytime sleepiness may reflect various causes:

•  It can be the primary symptom such as in narcolepsy;

•  it may be induced by lifestyle factors such as work conditions, poor sleep hygiene habits, or psychotropic consumption;

•  it can be secondary to various psychiatric, breathing disorders;

•  it can be the result of circadian rhythms perturbations.

Thus, daytime sleepiness is most often caused by specific factors, which can be easily identified by the physician and consequently treated.

• Consequences of daytime sleepiness may affect several areas of functioning:

•  at work,

•  in social or marital life,

•  decreased concentration or memory problems.

In addition, a sleepy individual is at greater risk to have road, work-related or home-based accidents.

It is of importance to underline that we found twice as many subjects with severe daytime sleepiness having a road or machine accident in the previous twelve months as those individuals with no daytime sleepiness.

The high prevalence of daytime sleepiness clearly indicates that this is a very important public health problem requiring preventive and educational initiatives on a large scale.

The socioeconomic impacts of daytime sleepiness should appeal to public health authorities.