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Sleep Apnea. Concordance Between Non-reference and Reference Centres

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: January 19, 2007
Last Update Posted: April 1, 2015
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
Hospital Clinic of Barcelona
When a disorder is as prevalent as sleep apnea hypopnea syndrome various medical levels and strategies should be implicated. We to evaluate the degree of concordance in management between a sleep reference centre and non-reference centres.

Condition Intervention Phase
Sleep Apnea Procedure: SAHS diagnosis Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Diagnostic

Resource links provided by NLM:

Further study details as provided by Hospital Clinic of Barcelona:

Primary Outcome Measures:
  • Concordance in sleep apnea management between reference vs non reference centres

Secondary Outcome Measures:
  • Concordane betwen polysomnographic data

Estimated Enrollment: 90
Study Start Date: January 2000
Estimated Study Completion Date: April 2004
Detailed Description:

INTRODUCTION: When a disorder is as prevalent as SAHS, different medical levels should be involved to facilitate diagnosis for all patients, or at least those that are in moderate-severe or risk groups. A good option could be to transfer the patient assessment to non-reference centres (NRC). Therefore, the aim of the present study was to evaluate this strategy by analysing the degree of concordance between RC and NRC in treatment decision and management of SAHS patients.

MATERIALS AND METHODS: Study subjects: The study population consisted of 88 consecutive subjects with a suspicion of SAHS (age 50±11 years, 81 % male, BMI 30±4 K/m2) from the out-patient clinics of three NRC in the Barcelona area: Hospital Asil de Granollers, Hospital General de Vic and Hospital de Terrassa.

Study design: The patients were evaluated independently, at random, over the course of 1 month in the RC and NRC. In both types of centre, the patient evaluation was carried out on the basis of the clinical history, with a specific questionnaire about sleep disordered breathing, and a sleep study in the hospital. The evaluation was performed by a sleep physician in the RC and by a respiratory physician with training in sleep medicine in the NRC. In both cases, the choice of treatment was registered on an ordinal scale with four points: 1= No diagnosis of SAHS and patient is discharged; 2= Mild SAHS, patient should follow a conservative treatment and clinical control; 3= Moderate to severe SAHS, patient should begin continuous positive air pressure (CPAP) treatment; 4= Other sleep disorders are diagnosed (RC), or there is a need for full-night PSG owing to a discordance between clinical features and respiratory polygraphy in NRC. The indication for CPAP treatment followed the national-SEPAR guidelines summarized as: 1) Patients with severe SAHS-related symptoms with an AHI>10; or 2) Patients with mild to moderate clinical symptoms with an AHI>30. The human ethics committee of our hospital approved the protocol and informed consent was obtained from all the patients. Sleep studies: Reference hospital: Full-night polysomnography was performed in the usual manner. Briefly, the variables registered were electroencephalogram, chin electromyogram, electro-oculogram, tibial electromyogram, arterial oxygen saturation, ribcage and abdominal motion and their sum. Airflow was measured by cannula/thermistor. An apnea was defined as the absence or airflow equal to or greater than 10 seconds. Hypopnoea was defined by any discernible reduction in the amplitude of the airflow signal ending in an arousal and/or association with a 3% desaturation, with a duration of at least 10 seconds. An expert technician scored sleep stages and respiratory variables manually. An apnea-hypopnoea index (AHI) equal to or greater than 10 was considered abnormal.Non-reference centres: patients received a respiratory poligraphy with recording of body position, ribcage and abdominal motion, snoring, arterial oxygen saturation and airflow using a cannula/thermistor. The respiratory physician performed a manual scoring of the recording. The definitions of hypopnoea and apnea resembled those mentioned above, except in the case of arousal. Data analysis: Data were entered using SPSS 10.0 and imported to STATA 7.0 to perform the analysis (StatatCorp. 1999. Stata Statistical software: Release 7.0. College Station, TX: Stata Corporation). Descriptive analysis: Data were expressed as mean ± SD or percentage for quantitative and qualitative variables, respectively. For continuum variables, a logarithmic transformation was undertaken to normalise the distribution, if necessary. If the distribution was not symmetrical, data were expressed as percentiles. Concordance analysis: Evaluation of the concordance of the final outcome and the choice of treatment, between the RF and the NFC centres, was performed by using the statistic Kappa balanced, penalizing extreme discrepancies, following the classification of Landis & Koch (25). This procedure was also used for the concordance in the result of the AHI of the sleep study, categorised as follows: <10, 10-29, ≥30. Concordance in the results of the sleep study (AHI and CT90) was evaluated in accordance with the Band & Altman methodology and the concordance coefficient of Lin.


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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Supected sleep apnea

Exclusion Criteria:

  • Major diseases
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00424658

Hospital Clinic. Fundacio Clinic.IDIBAPS
Barcelona, Spain, 08036
Hospital Clinic.Fundacio Clinic.IDIBAPS
Barcelona, Spain, 08036
Sponsors and Collaborators
Hospital Clinic of Barcelona
Study Director: Josep Montserrat, MD Fundacio Clinic. IDIBAPS
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00424658     History of Changes
Obsolete Identifiers: NCT00424879
Other Study ID Numbers: Sleep concordance
First Submitted: January 17, 2007
First Posted: January 19, 2007
Last Update Posted: April 1, 2015
Last Verified: January 2007

Keywords provided by Hospital Clinic of Barcelona:
breathing disorders

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Respiration Disorders
Respiratory Tract Diseases
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases