CAT: Home versus in Lab Polysomnography Evidence Based Practice Critically Appraised Topic (CAT)
Camille Settelmeyer
University of Mary
Common Health Problems
NUR 568
Rhea Ferry, DNP
May 28, 2016
CAT: HOME VERSUS IN LAB POLYSOMNOGRAPHY EVIDENCE1
CAT: Home versus in Lab Polysomnography Evidence Based Practice Critically Appraised Topic (CAT)
Clinical Scenario
EK is a 52 year old woman who is experiencing daytime somnolence and headaches. She has a history of hypertension controlled with HCTZ and Lisonopril. She is suspected to have obstructive sleep apnea (OSA). Two of her sisters have been diagnosed with OSA and are successfully treated with home CPAP.
She is the mother to a 23 year old severely disabled son and is not able to be away from him overnight for an in lab sleep study. She is inquiring about the option of doing the study at home where she can be available if needed.
PICO Question
For patients with OSA is home polysomnography assessment as effective as testing a sleep lab for diagnosis and treatment?
Articles
- Campbell, A. J., & Neill, A. M. (2010, April 8). Home set-up polysomnograpy in the assessment of suspected obstructive sleep apnea. Journal of Sleep Research, 20, 201-213.
- Rosen, C. L., Auckley, D., Benca, R., Foldvary-Schaefer, N., Iber, C., Kapur, V., ... Redline, S. (2012). A multisite randomized trial of portable sleep studies and positive airway pressure auto-titration versus laboratory-based polysomnograpy for the diagnosis and treatment of obstructive sleep apnea: The homePAPstudy. SLEEP, 757-767.
Summary and Appraisal of Key Evidence
Campbell and Neill (2010) completed a study, beginning with 86 potential subjects. Thirty subjects met the inclusion criteria which included no serious co-morbid conditions. These participants received a total of three polysomnography (PSG) tests. Initially all received a lab based PSG. The group was then randomly assigned to have either a home PSG or lab PSG and thirdly, the other procedure. All studies recorded the same metrics including electroencephalogram, electro-oculogram, nasal pressure, oro-nasal flow, and oxygen saturation. Chest, abdominal and leg movement was also monitored.
Strengths of the study included standardized measurements and high inter-rater reliability. Both in lab and home studies were shown to provide adequate information for the diagnosis and treatment planning. The at home studies were less expensive, at a 25% savings. The at home set up protocol was well accepted by the patients.
Weaknesses include required training for home PSG setup. Only including low risk patients possibly affects the applicability to those with co-morbidities. Also both this study and a meta-analysis showed slightly underestimated apnea hyponea index (API) severity being slightly lower in home studies (Ghegan, Angelos, Stonebracker, & Gillespie, 2006). This study had the same findings, but the difference was minor, 6.6%. Another weakness of this study was the lack of a control measured night at home. The study included a relatively small sample due to excluding co-morbid patients. Also the acceptable home locations were limited to optimize the safety of the staff attending to the patients.
Opportunities included addressing the experience of higher signal loss with home studies but this was mitigated by adding redundant channels.
Threats included possible signal loss and limited acuity of patients that may be appropriate for home study.
The level of evidence was not stated in this article. The study design was valid. All of the studies met criteria for acceptable interpretable data production. Covariance analysis was completed to determine AHI differences between studies 2 and 3 as compared with initial in-lab study. Bland Altman plots showed a sensitivity and specificity at AHI cutoff values of 5, 10, and 15 events. These produced likelihood ratios that give strong correlations between the two sites of service.
Rosen et al (2012) completed a multisite randomized trial comparing laboratory based polysomnography (PSG) and home based PSG for the diagnosis and treatment of obstructive sleep apnea. This study included participants from a number of sleep programs throughout the country. The participants were 18 years and older with a high probability for OSA as identified using a clinical algorithm and the Epworth Sleepiness Scale scores over 11. 373 total participants were randomly assigned to receive a sleep study in the traditional lab or at home.
Strengths included both methods effective at identifying episodes of AHI and a decrease in cost of home studies approximately 25% less than lab studies.
Weaknesses included exclusion of those with comorbidity which may limit generalizability of the findings. A fair number of potential participants exited before the study 40% of lab and 49% of those identified for home study group. This was because of the lag time between identifying participants and providing the studies. 25% of those that were studied at home were given repeat lab studies to confirm data.
Opportunities include a slightly higher rate of compliance with treatment with the home studied patients at one and three months. At one month 30% of lab tested and 40% of home tested were compliant. At three months, 39% of lab tested and 50% of home tested were compliant with CPAP use. There was also opportunities for access with the lower cost of the test.
Threats included some difficulties training staff in home evaluation and learning new equipment. Changing payment models is also a threat to these testing options.
The study design was valid in its design. It was powered for noninferiortiy analysis with sample size estimates and equivalence test.
Clinical Bottom Line/ Implications for Practice
The quality of both of these studies is high. The designs were comprehensive and both lab based and home based PSG were performed and measured with the same criteria. The studies both validated that the home PSG was a reliable and less expensive option for testing for obstructive sleep apnea in patients without serious co-morbidities. In the case example, home PSG could be safely and effectively used for diagnosis of this patient that would have a difficult time completing a lab PSG. The availability of home tests may also vary greatly, but the studies show them to be a safe and effective alternative that may even increase compliance with therapy.
References
Campbell, A. J., & Neill, A. M. (2010, April 8). Home set-up polysomnograpy in the assessment of suspected obstructive sleep apnea. Journal of Sleep Research, 20, 201-213.
Ghegan, M. D., Angelos, P. C., Stonebracker, A. C., & Gillespie, M. B. (2006). Laboratory vesus portable sleep studies: a meta analysis. Laryngoscope, 116, 859-864. from
Rosen, C. L., Auckley, D., Benca, R., Foldvary-Schaefer, N., Iber, C., Kapur, V., ... Redline, S. (2012). A multisite randomized trial of portable sleep studies and positive airway pressure auto-titration versus laboratory-based polysomnograpy for the diagnosis and treatment of obstructive sleep apnea: The homePAPstudy. SLEEP, 757-767.
Discussion Questions:
- What are some risk factors for obstructive sleep apnea?
- Describe the Epworth Sleepiness Scale and how it is administered.
- What impact does obstructive sleep apnea have on the body?