Diagnosis of obstructive sleep apnea syndrome and its outcomes with home portable monitoring.
BACKGROUND
The use of portable respiratory monitoring (PM) has been proposed for the diagnosis of obstructive sleep apnea syndrome (OSAS), but most studies that validate PM accuracy have not followed the best standards for diagnostic test validation. The objective of the present study was to evaluate the accuracy of PM performed at home to diagnose OSAS and its outcomes after first validating PM in the laboratory setting by comparing it to polysomnography (PSG).


METHODS
Patients with suspected OSAS were submitted, in random order, to PM at the sleep laboratory concurrently with PSG (lab-PM) or at home-PM. The diagnostic performance was assessed by sensitivity, specificity, positive and negative predictive values, positive likelihood ratio (+LR), negative likelihood ratio (-LR), intraclass correlation coefficients, kappa statistic, and Bland-Altman plot.


RESULTS
One hundred fifty-seven subjects (73% men, mean age +/- SD, 45 +/- 12 yr) with an apnea-hypopnea index (AHI) of 31 (SD +/- 29) events/h were studied. Excluding inadequate recordings, 149 valid comparisons with lab-PM and 121 with unattended home-PM were obtained. Compared to PSG for detecting AHI > 5, the lab-PM demonstrated sensitivity of 95.3%, specificity of 75%, +LR of 3.8, and -LR of 0.11; the home-PM exhibited sensitivity of 96%, specificity of 64%, +LR of 2.7, and -LR of 0.05. Kappa statistics indicated substantial correlation between PSG and PM results. Bland-Altman plot showed smaller dispersion for lab-PM than for home-PM. Pearson product moment correlation coefficients among the three AHIs and clinical outcomes were similar, denoting comparable diagnostic ability.


CONCLUSIONS
This study used all available comparison methods to demonstrate accuracy of PM in-home recordings similar to that of repeated PSGs. PM increases the possibility of correctly diagnosing and effectively treating OSAS in populations worldwide.
de Oliveira
Ana Claudia Tonelli
ACT
Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Martinez
Denis
D
Clinica do Sono Sleep Clinic, Porto Alegre, RS, Brazil; Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil; Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address: dm@ufrgs.br.
Vasconcelos
Luiz Felipe T
LFT
Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Cadaval Gonçalves
Sandro
S
Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
do Carmo Lenz
Maria
M
Clinica do Sono Sleep Clinic, Porto Alegre, RS, Brazil.
Costa Fuchs
Sandra
S
Programa de Pós-graduação em Epidemiologia, Faculdade de Medicina, Porto Alegre, RS, Brazil; Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil.
Gus
Miguel
M
Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil; Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
de Abreu-Silva
Erlon Oliveira
EO
Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil.
Beltrami Moreira
Leila
L
Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil.
Danni Fuchs
Flávio
F
Cardiology Unit, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil; Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
D000328:Adult; D016001:Confidence Intervals; D005260:Female; D006699:Home Care Services; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D008991:Monitoring, Physiologic / Q000379:methods*; D017286:Polysomnography / Q000295:instrumentation / Q000379:methods*; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012891:Sleep Apnea Syndromes / Q000175:diagnosis*