Management of sleep apnea without high pretest probability or with comorbidities by three nights of portable sleep monitoring

Abstract

Study objectives: Obstructive sleep apnea (OSA) diagnosis using simplified methods such as portable sleep monitoring (PM) is only recommended in patients with a high pretest probability. The aim is to determine the diagnostic efficacy, consequent therapeutic decision-making, and costs of OSA diagnosis using polysomnography (PSG) versus three consecutive studies of PM in patients with mild to moderate suspicion of sleep apnea or with comorbidity that can mask OSA symptoms.

Design and setting: Randomized, blinded, crossover study of 3 nights of PM (3N-PM) versus PSG. The diagnostic efficacy was evaluated with receiver operating characteristic (ROC) curves. Therapeutic decisions to assess concordance between the two different approaches were performed by sleep physicians and respiratory physicians (staff and residents) using agreement level and kappa coefficient. The costs of each diagnostic strategy were considered.

Patients and results: Fifty-six patients were selected. Epworth Sleepiness Scale was 10.1 (5.3) points. Bland-Altman plot for apnea-hypopnea index (AHI) showed good agreement. ROC curves showed the best area under the curve in patients with PSG AHI ≥ 5 [0.955 (confidence interval = 0.862-0.993)]. For a PSG AHI ≥ 5, a PM AHI of 5 would effectively exclude and confirm OSA diagnosis. For a PSG AHI ≥ 15, a PM AHI ≥ 22 would confirm and PM AHI < 7 would exclude OSA. The best agreement of therapeutic decisions was achieved by the sleep medicine specialists (81.8%). The best cost-diagnostic efficacy was obtained by the 3N-PM.

Conclusions: Three consecutive nights of portable monitoring at home evaluated by a qualified sleep specialist is useful for the management of patients without high pretest probability of obstructive sleep apnea or with comorbidities.

Clinical trial registration: http://www.clinicaltrials.gov, registration number: NCT01820156.

Citation: Guerrero A, Embid C, Isetta V, Farre R, Duran-Cantolla J, Parra O, Barbé F, Montserrat JM, Masa JF. Management of sleep apnea without high pretest probability or with comorbidities by three nights of portable sleep monitoring.

Keywords: CPAP; comorbidities; home respiratory polygraphy; obstructive sleep apnea; polysomnography.

Figures

Figure 1

Flow chart of the patients during the study. In branch A, 27 patients we subjected to the 3 nights of type 3 portable monitoring at home (3N-PM) first. One patient was lost (during the 3 nights the oxymeter signal was not recorded), and one study was missed (during the first night the oxymeter signal was not recorded). The polysomnography (PSG) was then performed in 26 patients. In branch B, 29 patients received PSG first. When the 3N-PM were performed in this group, six studies were invalidated: two studies during night 1 (one recording of less than 180 min and another with no recording); one, during night 2 (no recording); and three during night 3 (two recording of less than 180 min and another unperformed by the patient).

Figure 2

Costs of the each diagnostic strategy. The costs of each diagnostic strategy were considered in an analysis of two equally effective alternatives. In the 3 nights of type 3 portable monitoring at home (3N-PM) branch, only one patient was lost and had to undergo PSG to reach a diagnosis. Fifty-five patients were considered as having valid recordings, although seven missed tests were found in a single night, which did not influence the final diagnosis. In the polysomnography (PSG) branch all 56 tests were valid. For PSG, the test cost for equal diagnostic efficacy was the sum of the test cost and the cost of repeated PSGs because of no valid recordings. For PM, the test cost for equal diagnostic efficacy was the sum of the test cost and the following: the cost of PSG for one patient with no valid PM recordings, and the cost of three patients with false-positive and false-negative results (False +/−).

Figure 3

Bland-Altman plots. Bland-Altman plots. Mean of polysomnography (PSG) and 3 nights of type 3 portable monitoring at home (3N-PM) apnea-hypopnea index (AHI) versus difference in AHI between PSG and 3N-PM. Central lines represent mean values whereas upper and lower lines represent the agreement limits (mean ± 1.96 standard deviation of the differences).

Figure 4

Receiver operating characteristic curves. Receiver operating characteristic (ROC) curves for the mean of the 3 nights of type 3 portable monitoring at home based on the four polysomnographic cutoff points of obstructive sleep apnea (≥ 5, ≥ 10, ≥ 15, and ≥ 30). AHI, apnea-hypopnea index; AUC, area under the curve; CI, confidence interval; PSG, polysomnography.