Comparing a Combination of Validated Questionnaires and Level III Portable Monitor with Polysomnography to Diagnose and Exclude Sleep Apnea

Abstract

Study Objectives: Questionnaires have been validated as screening tools in adult populations at risk for obstructive sleep apnea (OSA). Portable monitors (PM) have gained acceptance for confi rmation of OSA in some patients with a high pretest probability of the disorder. We evaluated the combined diagnostic utility of 3 validated questionnaires and a Level III PM in the diagnosis and exclusion of OSA, as compared with in-laboratory polysomnography (PSG) derived apnea hypopnea index (AHI). Methods: Consecutive patients referred to the Sleep Disorders Clinic completed 3 testing components: (1) 3 questionnaires (Berlin, STOP-Bang, and Sleep Apnea Clinical Score [SACS]); (2) Level III at-home PM (MediByte) study; and (3) Level I in-laboratory PSG. The utility of individual questionnaires, the Level III device alone, and the combination of questionnaires and the Level III device were compared with the PSG. Results: One hundred twenty-eight patients participated in the study (84M, 44F), mean ± SD age 50 ± 12.3years, BMI 31 ± 6.6 kg/m 2 . At a PSG threshold AHI = 10, the PM derived respiratory disturbance index (RDI) had a sensitivity and specifi city of 79% and 86%, respectively. The sensitivity and specifi city for the other screening tools were: Berlin 88%, 25%; STOP-Bang 90%, 25%; SACS 33%, 75%. The sensitivity and specifi city at a PSG AHI = 15 were: PM 77%, 95%; Berlin 91%, 28%; STOP-Bang 93%, 28%; SACS 35%, 78%. Conclusions: Questionnaires alone, possibly given a reliance on sleepiness as a symptom, cannot reliably rule out the presence of OSA. Objective physiological measurement is critical for the diagnosis and exclusion of OSA. S C I E N T I F I C I N V E S T I G A T I O N SO bstructive sleep apnea (OSA) affects 24% of adult men and 9% adult women in North America.1-3 A questionnairebased survey in 2009 by the Public Health Agency of Canada (PHAC) estimated that 22% (5.4 million) of adult Canadians report either being diagnosed with sleep apnea (3%) or are at high risk for OSA (19%). 4 Untreated OSA has been associated with serious long-term medical and neurocognitive complications, including premature death. 5-7The recommended diagnostic test for OSA includes an overnight in-laboratory technologist-attended sleep study (Level 1 polysomnography [PSG]).8 In addition to monitoring sleep stage by electroencephalography, electro-oculography, and chin electromyography, PSG includes monitoring of electrocardiography, respiratory effort, airfl ow (nasal pressure and oronasal thermal sensor) and snoring, oxygen saturation, leg movements via electromyography on the anterior tibialis muscles, and body position. This procedure is time-and laborintensive, and costly. Given the large number of individuals in the population likely to be suffering from OSA, it is not surprising that a great majority remain undiagnosed. 9 It is clear that the challenge of providing a diagnosis of OSA to those suffering from the disorder cannot rely on in-laboratory polysomnography alone, and that simpler and less expensive 10-13Several qu...

Clinical Practice Guideline for Diagnostic Testing for Adult Obstructive Sleep Apnea: An American Academy of Sleep Medicine Clinical Practice Guideline

“…33 Our review identified nineteen studies that evaluated the performance of the Berlin Questionnaire against PSG in the identification of patients with OSA. [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] The studies were conducted in a wide variety of geographic locations including Brazil, 38 Canada, 34,42 Greece, 37 Iran, 36 Korea, 40 Turkey, 43 and the United States. 41,44 Various patient populations were considered, including those in primary care clinics, sleep clinics, the veteran population, and patients with cardiac disease.…”

“…62 We identified ten studies, involving primarily middle-aged, obese males suspected of OSA that evaluated the performance of STOP-BANG questionnaire against PSG in the identification patients with OSA. 42,[49][50][51][52][63][64][65][66][67] The overall findings reveal that the STOP-BANG questionnaire had high sensitivity, but low specificity for the detection of OSA. These findings became more pronounced when higher levels of OSA category cutoffs were considered.…”

During economic crisis can sleep questionnaires improve the value of oximetry for assessing sleep apnea?

“…Several studies have shown that portable diagnosis and management of OSAHS in sleep centres may produce comparable patient outcomes with in laboratory sleep studies (15)(16)(17) and that the predictive values of oximetry in high risk populations as ours are high (18,19). The degree of oxygen desaturation varies between individuals depending on baseline arterial oxygen saturation, the presence or absence of lung disease and lung volumes (20)(21)(22)(23) COPD or heart failure. Unfortunately we did not perform pulmonary function testing for all our patients.…”

“…In the study of Pereira et al (22) previously well-validated questionnaires were evaluated to diagnose or exclude OSAHS in combination with a level III portable monitor. They found that objective data from the portable monitor was superior to questionnaires in OSAHS diagnosis and that the use of questionnaires did not further enhance the diagnostic utility of the portable device.…”

Undiagnosed Obstructive Sleep Apnea and Postoperative Outcomes: A Prospective Observational Study

“…Questionnaires have to be supplemented by the use of a level III study [33] or postoperative respiratory monitoring [4] to identify OSA. The use of a level III study in patients being at risk for OSA is needed for reliably ruling out OSA preoperatively and can establish a definite intraand postoperative plan.…”