Daytime Sleepiness

Last edited   | 05/11/2012

Summary by Maurice M. Ohayon, MD, DSc, PhD

Reference to cite: Ohayon MM, Caulet M, Philip P, Guilleminault C, Priest RG. How sleep and mental disorders are related to complaints of daytime sleepiness. Arch Intern Med 1997;157:2645-52.

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.

References