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Apnea Positive Pressure Long-Term Efficacy Study

This study has been completed.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI) Identifier:
First received: January 9, 2003
Last updated: February 23, 2010
Last verified: July 2009
The purpose of this study is to determine the effectiveness of nasal continuous positive airway pressure (CPAP) therapy for the treatment of obstructive sleep apnea syndrome (OSAS).

Condition Intervention Phase
Lung Diseases
Sleep Apnea Syndromes
Device: Positive Pressure Respiration
Device: Sham CPAP machine
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: APPLES: Apnea Positive Pressure Long-Term Efficacy Study

Resource links provided by NLM:

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Primary Outcome Measures:
  • Effect of CPAP on neurocognitive function [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Attention and psychomotor (A/P) function [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]
  • Learning and memory (L/M) function [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]
  • Executive and frontal-lobe (E/F) function [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]
  • Sleepiness/Alertness [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]
  • Mood [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]
  • Quality of Life [ Time Frame: Measured at diagnostic visit (baseline) and 2 months and 6 months post intervention ] [ Designated as safety issue: No ]

Enrollment: 1105
Study Start Date: September 2002
Study Completion Date: September 2008
Primary Completion Date: August 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1
Active CPAP
Device: Positive Pressure Respiration
Nightly nasal continuous positive airway pressure (CPAP)
Placebo Comparator: 2
Device: Sham CPAP machine
Sham CPAP machine will be used for participants in the placebo group.

Detailed Description:


Nasal CPAP therapy is in widespread use as the primary treatment for OSAS, a sleep-related breathing disorder affecting more than 15 million Americans. The therapeutic effectiveness of CPAP in providing significant, stable, and long-term neurocognitive or other functional benefits to patients with OSAS has not been systematically investigated.


The study is a randomized, blinded, sham-controlled, multi-center trial of CPAP therapy. The principal aims of the study are: 1) to assess the long-term effectiveness of CPAP therapy on neurocognitive function, mood, sleepiness, and quality of life by administering tests of these indices to subjects randomly assigned to active or sham CPAP; 2) to identify specific neurocognitive deficits associated with OSAS in a large, heterogeneous subject population; 3) to determine which deficits in neurocognitive function in OSAS subjects are reversible and most sensitive to the effects of CPAP; 4) to develop a composite multivariate outcome measure from the results of this study that can be used to assess the clinical effectiveness of CPAP in improving neurocognitive function, mood, sleepiness, and quality of life; and 5) to use functional magnetic resonance imaging to compare cortical activation before and after CPAP therapy, and to assess whether this change is associated with improvement in specific neurocognitive task performance. The primary endpoint of the study is the effect of six months of CPAP treatment on neurocognitive function. A total of 1100 subjects (550 per treatment group) will be enrolled from the patient populations at five sites (Stanford University; University of Arizona; Brigham and Women's Hospital; Massachusetts; St. Luke's Hospital, Missouri; St. Mary Medical Center, Washington).


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male or female adults age 18 years or older with a diagnosis of OSAS using clinical criteria defined by the study protocol
  • Study participation may require seven or more laboratory visits over six months

Exclusion Criteria:

  • Prior treatment for OSAS with continuous positive airway pressure or surgery
  • Potential sleep apnea complications that may affect the health or safety of the participant, including low blood oxygen, recent near-miss or prior automobile accident due to sleepiness, congestive heart failure, history of angina, coronary artery disease, myocardial infarction or stroke, cardiac rhythm disturbance, and chronic neurological disorders affecting neurocognitive abilities or daily function
  • The use of hypnotics, anxiolytics, sedating antidepressants, anticonvulsants, sedating antihistamines, stimulants or other medications likely to affect neurocognitive function and/or alertness
  • Respiratory disease requiring medications (unless on stable medications for 2 months)
  • Cancer, unless in remission for greater than one year and not taking exclusionary medications
  • Self-reported renal failure
  • Pregnancy anytime during a subject's participation
  • Psychiatric illness, as defined by a DSM-IV diagnosis, except for depression or mild anxiety
  • Narcolepsy, idiopathic hypersomnolence, DSM-IV chronic insomnia, restless legs syndrome, or rapid eye movement (REM) behavior disorder
  • Current use of diurnal or nocturnal supplemental oxygen
  • Significant vision, hearing, or coordination problems
  • Difficulty understanding or speaking English
  • Currently working night or rotating shifts
  • Consumption of more than 10 caffeinated beverages per day (approximately 1,000 mg per day)
  • Smokers whose habit interferes with the overnight polysomnogram or with the battery of testing during the day
  • Consumption of more than 2 alcoholic beverages per day
  • Any illicit drug usage or marijuana usage more than once a week
  • Any individual in the household currently on CPAP or on CPAP in the past
  • A score of 26 or less on the Mini Mental State Examination (MMSE)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00051363

United States, Arizona
University of Arizona AHSC
Tucson, Arizona, United States, 85724
United States, California
Stanford University School of Medicine
Palo Alto, California, United States, 94305
United States, Massachusetts
Brigham & Women's Hospital
Boston, Massachusetts, United States, 02459
United States, Missouri
St. Luke's Hospital
Chesterfield, Missouri, United States, 63017
United States, Washington
St. Mary Medical Center
Walla Walla, Washington, United States, 99362
Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Study Chair: William C. Dement, MD, PhD Stanford University
Principal Investigator: Clete A. Kushida, MD, PhD Stanford University
  More Information

Responsible Party: Clete A. Kushida, M.D., Ph.D., Principal Investigator, Stanford University School of Medicine Identifier: NCT00051363     History of Changes
Other Study ID Numbers: 150  U01HL068060 
Study First Received: January 9, 2003
Last Updated: February 23, 2010
Health Authority: United States: Federal Government

Keywords provided by National Heart, Lung, and Blood Institute (NHLBI):
Obstructive Sleep Apnea

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Lung Diseases
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on October 21, 2016