Apuntes

CALIDAD DEL SUEÑO EN ESTUDIANTES UNIVERSITARIOS:
IMPORTANCIA DE LA HIGIENE DEL SUEÑO

Juan Carlos Sierra*, Carmen Jiménez-Navarro*, Juan Domingo Martín-Ortiz*

SUMMARY
Sleep disorders constitute one of the most relevant health problems
in Occidental societies. Between 30-40% of the population suffers
from insomnia, whereas 1-10% suffers sleep apneas, and around
60% of shift workersreport disturbances in the circadian rhythm.
The importance of a good sleep quality is not only fundamental in
determining health, but is also a propitiatory element for a good
quality of life. Sleep quality is not only defined as a good night
sleep. It also includes a good daytime functioning (the adequate
level of attention needed to complete different tasks). Sleep disorder
incidence rates indifferent populations need to be studied in
order to better understand this daytime functioning and its
determining factors. To reach this objective, and because of
difficulties involved in administering a polysomnographic evaluation
to detect sleep quality, self-report measures are used in the majority
of the cases (for example, the Pittsburg Sleep Quality Index).
From a behavioralevaluation point of view, sleep is made up of
four different dimensions: circadian time, that is, the time of day
when sleep is located, the organism’s intrinsic factors (age, sleep,
sleep patterns), a subject’s facilitating and inhibiting behaviors,
and the environment in which the subject sleeps. As sleep hygiene
affects these last two dimensions, in our study we focus on the
inhibiting behaviors(psychoactive substance consumption). The
present investigation uses the Pittsburg Sleep Quality Index to
analyze the subjective sleep quality in a sample of 716 university
students (584 females and 132 males). The investigation also
evaluates the effects of alcohol, caffeine, and tobacco consumption
on sleep quality. The Pittsburg Sleep Quality Index provides a
total sleep quality score andpartial scores for seven different
components: subjective sleep quality; sleep latency; sleep duration;
habitual sleep efficiency; sleep dysfunctions; use of hypnotic
medication; and daytime dysfunction. The score for each one of
the seven components oscillates between zero (absence of
difficulty) and three (severe difficulty). The total score ranges
from 0 to 21, with a cut-off point of 5,which differentiates between
good and bad sleepers. This instrument reveals satisfactory
psychometric data in the Spanish population, demonstrating an
internal consistency which oscillates between 0.67 in a student
sample and 0.81 in a clinical sample. A sensitivity of 88.63% and
a specificity of 74.19% is obtained when analyzing the validity.

The results show that approximately 30% ofthe sample presents
a poor sleep quality, an excessive latency, and a poor sleep efficiency.
These results suggest that difficulties in falling asleep characterize
a poor sleep quality in younger subjects, whereas nighttime and
premature awakenings are more common among older subjects.
The total scores for the Pittsburg Sleep Quality Index reveal that
60.33% of the sample score higher thanfive, therefore defining
these subjects as poor sleepers. The only difference found between
males and females is observed in the hypnotic consumption
component, in which women presented higher scores. The absence
of differences in sleep quality between men and women could be
due to the sample median age (20.92 years), since the poorest
sleep quality in women is more evident as age increases.However,
our data support evidence that the use of hypnotics is more frequent
in women than in men. It is also demonstrated that an excessive
use of alcohol, caffeine, and nicotine provokes a variety of sleep
disturbances: an increase in sleep latency, nocturnal awakenings, a
reduction in slow sleep waves, a reduction in the total sleep time,
and a poor self-report. However, the effect of...