Current State of non-Sleep Laboratory Diagnosis of OSA Clinical suspicion Probably accurate in obvious cases but cannot be routinely relied upon Lacks sensitivity and specificity Questionnaires Validate clinical suspicion None sufficiently sensitive or specific as a stand alone diagnostic method Are useful as an adjunct to clinical decision-making, triage – MAP, Berlin are reasonable to consider
Cardiovascular Consequences of Sleep-Disordered Breathing Report of a Workshop From the National Center on Sleep Disorders Research and the National Heart, Lung, and Blood Institute Circulation 2004 109:951-957 Basic ScienceClinical Epidemiology Clinical Therapeutic Studies Sleep Disordered Breathing & Cardiovascular Disease Cellular / molecular studies Mouse models Pathway studies for humans High – risk patient subsets Development of new treatment approaches Develop new tools for population screening Prospective cohort studies Incorporation of SDB / Sleep Deprivation in ongoing CV cohort studies
Institute of Medicine Report 2006 What is needed? Expand awareness among health care professionals through education and training. Develop and validate new and existing diagnostic and therapeutic technologies.
Ability of type III monitors in the home setting to identify AHI suggestive of OSAHS in laboratory-based polysomnography Pos LR >10 Neg LR < 0.1 From Trikalinos et al, AHRQ, 07
Current State of non-Sleep Laboratory Diagnosis of OSA Diagnostic equipment Terminology: Portable, ambulatory, out- of-sleep lab, HST, etc Types of equipment Type 2 Type 3 Type 4
Type 2 Monitors: Mini-PSG Advantage Multiple channels Flexibility of signal type Comprehensive Use standard software of a base system Portability Extensive track-record in research applications Disadvantage Tech hook up Expensive Probably no reimbursement for home PSG Loss of signal – no way to easily correct problem
Type 3 Monitors: Cardio-pulmonary Studies Advantage Easy to set up: easily done by most patients; technician not required Inexpensive (<$10K) Very portable Reduced number of signals Disadvantage Reduced number of signals No reimbursement Signal loss at home; not way to correct Requires scoring or at least overview of scoring by tech; takes longer than you think
Type 4 Monitors: Oximetry + Advantage Most portable Inexpensive Easy to set up Core signals: oxygenation and airflow Now may include PAT signal Disadvantage No reimbursement Minimal number of signals – may not capture important aspects of some OSA Signal loss
Current Uncertainties: Type 3 & 4 Devices How many signals are needed? Which signals add the most value? Are there clinical populations that this does not work in? How can technology be combined with clinical decision making to optimize OSA diagnosis outside the sleep lab?
More uncertainties… New technologies – how do they fit in to the existing PSAT device classification? WatchPAT-100 PTT ARES New systems on the horizon will have capabilities to be a level 2-4 by adding or taking away modules
Stardust Made by Respironics, Inc Level 3 device Measures: airflow, resp. effort, oximetry, heart rate, body position Well validated Moderately expensive, ~$7000 but subsequent units are cheaper Moderate tech time for scoring
Embletta Somnologica/Medcare Level 3 Measures: Airflow, respiratory effort, oximetry, body position Well-validated, widely used Moderately expensive, similar to Stardust Moderate tech time for scoring
Apnea link Resmed, Inc. Level 4 Measures: airflow +/- oximetry Some validation; generally shows that it’s accurate in detecting more severe OSA Relatively inexpensive; consumables less than $15 for earlier models Limited tech time
WatchPAT Works on principle of changes in peripheral arterial tonometry Indirect measure of ANS activity PAT is a surrogate marker for apnea, hypoxia Moderately expensive to purchase; individual probes are recurring cost Minimal to no tech time for scoring
Other devices Apnea Risk Evaluation System (ARES) New unit Cardiopulmonary monitor Moderately expensive Some local experience with it Tech time minimal
Night Cap Developed by Dr. Allan Hobson Head cap that can measure NREM vs. REM sleep Limited validation studies Not used much anymore as best as I can tell ?Commercial availability
Bodymedia -Sensewear Bodymedia, Inc Wearable devices that sense activity – more akin to actigraphy Evolving more into a obesity management solution than a sleep rhythm detector
Scenario 1 Your objective is to measure psychological “well-being” in a cohort of Iraq war veterans over a 3 year span beginning with the end of military service You are concerned that sleep disorders will be a mediator of psychological health Your are also concerned that sleep disorders will confound the sleep measure
Scenario 1, continued Your budget is very limited How can you assess for sleep apnea in a cost efficient way? How can other sleep disorders be assessed? What tools would you use and why?
Scenario 2 Your objective is to screen a population of factory workers for sleep apnea as part of a wellness program you are consulted about You have 2500 middle-aged men and women to screen Your budget total budget for sleep screening is $20 per person but you can get some equipment through a different grant
Scenario 2, continued How would you screen for sleep apnea? What are the pros and cons? What else do you need to know?
Scenario 3 Your objective is to measure sleep and rule out sleep apnea in a study of obese individuals contemplating bariatric surgery and stress This is a pilot study and you have essentially no budget but you have friend who will help with the sleep part for free (within reason).
Scenario 3, continued What would your approach be? How might you combine approaches?
Further reading http://www.cms.hhs.g ov/mcd/viewtechasse ss.asp?from2=viewte chassess.asp&where =index&tid=48& http://www.cms.hhs.g ov/mcd/viewtechasse ss.asp?from2=viewte chassess.asp&where =index&tid=48& Or, go to www.ahrq.gov and search for completed technology assesments in 2007 www.ahrq.gov