Development and validation of a screening instrument for Obstructive Sleep Apnea Syndrome in healthy workers

Obstructive Sleep Apnea Syndrome (OSAS) is a disorder that is characterized by
repetitive episodic partial or complete collapse of the pharyngeal airway.
These nightly events interfere with normal restorative sleep and are
responsible for the daytime symptoms like excessive daytime, poor concentration
and fatigue. OSAS is associated with increased cardio vascular and cerebral
vascular morbidity and mortality. Philips NV Netherlands is planning to screen
a large part of their Dutch work force (approximately 16.000 employees) for
OSAS. Because of these large numbers a simple, but sensitive and specific
screening strategy needs to be developed and tested. The proposed study will
investigate and validate in a population of approximately 300 healthy workers
from Philips NV a set of diagnostic questionnaires, supplemented with airflow
registration with the RU sleeping device. The gold standard will be the
combined result from PSG with the ALICE PDX, performed at home, and answers to
questions on sleepiness from questionnaires.

Primary Objective(s):
Find the best 2 or 3 step strategy for screening of OSAS in a Dutch employee
population to optimize a large scale screening program. Home PSG with the ALICE
PDX, combined with answers on sleepiness, is the gold standard. This includes
the following:
- which questionnaire, or set of questions has the highest accuracy in terms of
sensitivity, specificity and positive and negative predictive value
- define the low and high cut-off values of the used questionnaires for
negative and positive test results
- are limited IV home sleep studies in this population feasible
- what is the accuracy of the complete strategy
Secondary Objective(s):
- calculate the costs of the strategy
- estimate the prevalence of OSAS in this population

The study will be designed as a diagnostic study.
Home PSG with the ALICE PDX, combined with answers on sleepiness, is the gold
standard.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness: Subjects have to complete a questionnaire and
will be asked to perform sleep registrations during two nights. The risks
associated with participation in the study are negligible. Those subjects with
Obstructive Sleep Apnea will be offered treatment. All other subjects will not
benefit in any way from this study. It is the only way to validate a diagnostic
strategy that will be used to screen approximately 16.000 similar employees.