Table 2: Standardized sleep questionnaires.
Questionnaire |
Description |
|
Epworth Sleepiness Scale
(ESS)13 |
The ESS is a scale intended to
measure daytime sleepiness by use of a very short questionnaire. The
questionnaire asks the subject to rate his or her probability of falling
asleep on a scale of increasing probability from 0 to 3 for eight different
situations [13].
The scores for the eight questions are added together to obtain a single
number. A number in the 0-9 range is considered to be normal while a number
in the 10-24 range indicates that expert medical advice should be sought [13]. |
|
Insomnia
Severity Index 14-16 |
The
ISI is a seven-item self-report questionnaire. The seven answers are added up
to get a total score. The scale assesses sleep-onset and sleep maintenance
difficulties, associated distress, and interference with daily functioning.
Each item is rated on a 0-4 scale. The
time period is the past fortnight. The guidelines for the interpretation of
scores are: no clinically significant insomnia (0-7), subthreshold
insomnia (8-14), clinical insomnia of moderate severity (15-21) and severe
clinical insomnia (22-28) [16]. |
|
The Pittsburgh Sleep Quality
Index (PSQI) is a self-rated questionnaire which assesses sleep quality and
disturbances over a 1-month time interval. Nineteen individual items generate
seven "component" scores: subjective sleep quality, sleep latency,
sleep duration, habitual sleep efficiency, sleep disturbances, use of
sleeping medication, and daytime dysfunction. The sum of scores for these
seven components yields one global score. A global PSQI score greater than 5
is supposed to distinguish good and poor sleepers [17]. |
||
Restless Legs Syndrome-
Diagnostic Index (RLS-DI)19 |
The RLS-DI consists of 10 items
which are related to the essential diagnostic criteria established by the
International RLS Study Group (five items) as well as their supportive
criteria (3 items) and features associated with RLS (2 items). Items have to
be completed using three categories per item that address frequency of
occurrence of symptoms or certainty of presence or absence of other
diagnostic information. Within the present study only five items were
explored. |