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Volume I and II of The Nightlight
About Us
Sleep Data, Inc. was among the nation’s first providers of in-home dianostic testing for sleep-disorderd breathing. Since 1995 Sleep Data has performed thousands of studies in all fifty states. Traditional sleep laboratories can be costly and inconvenient. Few patients look forward to spending time away from home to assess their possible sleep-disordered breathing. Home based sleep studies offer an accurate and timely alternative. Administered in a patient’s own environment, in his or her own bed, the data has often been found to more closely reflect reality. Equally important, the technology Sleep Data uses for the in-home studies has been scientifically validated (please see reference list). The company’s university trained staff has years of experience in the diagnosis and treatment of sleep-disorderd breathing. Our portable recording system accuratedly measures the most important physiological parameters as defined by the American Academy of Sleep Medicne. The data include:
•heart rate
•abdominal & thoracic respiratory effort
•nasal airflow
•oxygen saturation
•snoring
•body position
We make completing an in-home sleep study easy for you patients. Once a physician’s referral is made by fax or phone, a technician experienced in sleep disorders will contact your patient to schedule the test. We work closely with them to arrange pick-up/delivery of the recorder at their home. They will receive clear, detailed instructions on how to use the recorder and we are available twenty-four hours a day for their questions. When the recorder returns to Sleep Data we will download the data and anazyze it. Reports are immediately faxed and mailed to the referring physician. Many insurers require objective clinical measures before approving treatments such as CPAP (continuous positive airway pressure) and dental devices or surgical interventions such as bariatric surgery, maxillofacial reconstruction, uvlopalatopharynogolplasy. A sleep study can furnish the patient’s health care provider with the definitive information needed to implement an effective treatement plan. Sleep Data provides fast and efficient home sleep studies to your patients. We can typically complete a homebased study, including the physician’s interpretation, within one week of the referral and even more quickly in special situations. We look forward to working with you and your patients.
Why Test At Home?
Proven Techniques & Protocols
Sleep Data provides nationwide, high quality, convenient and cost-effective in-home sleep studies for patients in whom you suspect obstructive sleep apnea syndrome (OSAS). We are a market leader in providing innovative solutions to this severly under diagnosed segment of the population. We have performed thousands of studies in all fifty states.
Recent work further confirms the validity of home sleep studies. Dr. Jose Loredo, asst. prof. Pulmonary/Critical Care/Sleep, University of California, San Diego studied 40 patients with a in-home study followed by an in-lab study (1). All had classical symptoms of OSAS. Correlation between the home study respiratory disturbance index (RDI) and the in-lab RDI was excellent (r=0.8). All patients diagnosed with apnea by in-lab studies had positvie in-home studies. In face, one patient with a negative in-lab study had a positvie in-home study and was found to truly have OSAS! Thyis study reflects our own experience that our home-based study is not only cost effective but has excellent sensitivity and specificity.
A home-based study, including the physician’s interpretation, can be completed within one week of the referral and even more quickly in special situations. Once a referral is received we will take care of the rest. When necessary, we verfy insurance benefits prior to calling the patient to schedule their test. The sleep recorder will be deliverd and piced up from their home or office. And this service is nationwide! The patient will be studied under their usual sleeping conditions in the privacy of their own home, rather than in an unfamilar hospital setting. Our university trained staff is available 24 hours a day to further assist patients. The completed study is analyzed by our trained clinicians and interpreted by a pulmonary physicians trained in sleep medicine. Sleep Data provides a recommended starting CPAP pressure based on a publishedd regression equation which takes into account physicoligc and seleep parameters (2). Fitzpatrick et al. have demonstrated the valididty of using a regression equation to arrive at a starting CPAP pressure (3). With proper follup-up, the use of this equation is an excellent way to intitiate CPAP therapy. More on this in a future newsletter.
Our Comprehensive Report will Include:
•Calculation of RDI and autonomic arousel index
•Oxygen saturations, heart rate, snoring and body position
•Study description
•The patient’s sleep history and sleep hygiene
•Patient’s daily medications
•Post sleep study report
•Our pulmonary physician’s clinical interpretation and recommendations
•Continuous positive airway pressure (CPAP) level or bi-level airway pressure recommendation if appropriate
Improved Access to Health Care
A landmark study by Yound et al. found that OSAS remained undiagnosed in 82% of men and 93% of women (4). All too often patients have to wait for weeks or months for in-lab sleep studies due to scheduling backlogs. Tradional sleep laboratories can be quite costly and inconvenient. Some patients in rural areas might have to travel for hours to be studied. Sleep Data’s home studies dramatically improve patients’ access to health care and facilitate timely institution of appropriate treatment.
Many health care system utilize home-based studies. They include Veterans Affairs Hospitals, University of California Medical Centers and Kaiser Permanente Hospitals. Redline et al. demonstrated that a typical patient with suspected OSAS can be diagnosed and treated entirely outside the polysomnography laboratory (5).
References:
1. Loredo, J.S. Are unattended home sleep studies adequate to diagnose obstructive sleep apnea? Abstracts of Original Investigations. Chest: 2002; 42S
2. Hoffstein, Z et al. Predicting effective continuous positive airway pressure. Chest: 2000; 117;1061-1064.
3. Fitzpatrick, M. et al. Can patients with obstructive sleep apnea titrate their own continous positive airway pressure? Am J Respir Crit Care Med: 2003;167:716-722
4. Young, T. et al. Occurrences of sleep-disorderd breathing among middle-aged adults. New Engl J Med: 1993 (328): 1230-1235
Redline, S et al. Measurement of sleep-related breathing disturbances in epidemiologic studies. Chest: 1991;100:1281-1286
Validation of Home Based Sleep Testing
We are happy to answer any questions you may have or provide you with a list of home sleep study publications. The following is a partial list of studies validating the use of home sleep recorders:
Ballester, E. et al, Evaluation of a portable espiratory recording device for detecting apneas and hypopneas in subjects from a general population. Eur Respir J: 2000, July; 16 (1):123-7
Emsellem, H. et al, Verification of sleep apnea using a portable sleep apnea screening device. S Med J: 1990, 83 (7): 748-752.
Parra, O. et al, Should patients with sleep apnea/hypo-pnea syndrome be diagnosed and managed on the basis of home sleep studies? Eur Respir J: 1997, 10: 1720-24
Redline, S et al, Measurement of sleep-related breathing disturbances in epidemiologic studies. Chest: 1991, Nov; 100 (5); 1281-1286
Volume II of The Nightlight
Relationship Between Obsrtructive Sleep Apnea Syndrome and Hypertension
Hypertension affects an estimated fifty million americans. It is a well-established rish factor for the development of heart disease and stroke. Obstructive sleep apnea syndrome (OSAS) is thought to affect as many as twenty milion Americans. There is increasing evidence to suggest that OSAS can lead to hpypertension. therefore, the diagnosis and effective treatment of OSAS may help to decrease the incidence as well as the morbidity and mortality of hypertension. this issue of the Nightlight will focus on some of the data suggesting a casua relationship between OSAS and hypertension.
A prospective study of 709 patients by Peppard et al (1) showed a dose-response relationship between OSAS and the presence of hypertension after four years of follow-up. The data suggest a two-fold increase in the icidence of hypertension for those with mild apnea (apnea-hypopnea index (AHI) 5-14.9) and a three-fold increase for those with an AHI >15.
The authors controlled for body mass index, neck and waist circumference, age, gender and weekly use of alcohol and cigarettes. Interestingly, there was no evidence of a threshold AHI. Even values within the “normal” range (AHI 0.1-4.9) were associated with an increased probability of hypertension (odds ratio of 1.4). The authors concluded that sleep-disordered breathing is a likely risk factor for the development of hypertension and its subsequent morbidities.
Further support for a link between hypertension and OSAS is provided by the work of Lavie and Hoffstein (2). They suggest that patients with OSAS and poorly controlled hypertension, despite anti-hypertensive therapy, tended to have worse OSAS than those whose hypertension was better controlled with anti-hypertension and OSAS might be related but it did not examine how hypertension and OSAS might but it did show that with each additional apnec event the odds of hypertension increased by 1%. Once again demonstrating a dose-response relationship between apnea severity and the likelihood of hypertension.
Data from the Sleep Heart Health Study (3) support an independent association between OSAS and hypertension. patients with the most sever apnea (> 30 events per hour ) were 30% more likely to have hypertension than those with mild sleep apnea (<15 events per hour) This is an ongoing national study assessing more than 6,000 middle-aged participants.
Nasal continuous positive airway pressure (nCPAP), which utilizes air pressure to stent open the airway and prevent its collapse during sleep, is the most effective treatment for OSAS. Pepperell et al (4) studied 118 men with OSAS and determined that one month of therapy with nCPAP resulted in a decrease in mean ambulatory blood pressure of 3.3 mmHg. Patients with the most severe apnea (<33 events/hour) demonstrated the greatest benefit, and the reduction in blood pressure was particularly striking (6.6 mmHg) in a small subgroup that was on anti-hypertensive medication and used therapeutic nCPAP. While this was a small group and one must be cautios when interpreting the results, the data suggest that untreated OSAS may not only predispose one to hypertension but untreated OSAS may also antagonize the effect of anti-hypertensive medication.
In Summary
Numerous studies support a link between OSAS and hypertension. The exact nature of this link and the extent to which effective therapy can modify it have yet to be fully elucidated. However, with OSAS potentially affecting twenty million Americans, the importance of diagnosing and effectively treating OSAS is quite apparent.
References:
1. Peppard, P. et al. “Prospective study of the association between sleep-disordered breathing and hypertension.” NEJM 342:1378-1384, 2000
2. Nieto, F et al. ”Association of Apnea, and Hypertension in a Large Community-Based Study.” JAMA 283:1829-1836, 2000
3. Lavie, P. and Hoffstein, V. “Sleep apnea syndrome; a possible contributing factor to resistant hypertension.” Sleep 24: 721-725, 2001
4. Pepperell, J. et al. “Ambulatory blood ressure after therapeutic and sub-therapeutic nasal continuous positive airway pressure for obstructive sleep apnea: a randomized parallel trial.” the Lancet 359: 204-210, 2001
Sleep Data’s Mission Statement
Sleep Data Inc. provides timely, expert, home based sleep studies thereby improving patients’ health and understanding, while lowering overall health care costs.
Sleep Data, Inc