Objectives: To evaluate the reliability of home respiratory polygraphy for the diagnosis of sleep apnea-hypopnea syndrome (SAHS) and to compare the cost of this technique with that of nighttime polysomnography performed in a sleep laboratory.
Patients and methods: This was a prospective study of a random sample of patients with clinically suspected SAHS in which the participants who underwent both home respiratory polygraphy and nighttime polysomnography were blinded as to the results of their first test. Costs were calculated based on a theoretical population of 1000 individuals. A t test for paired samples, the Pearson correlation coefficient, and a receiver operator characteristic curve were used for the statistical analysis.
Results: The study population was composed of 45 patients with a mean (SD) age of 52.3 (11) years of whom 21 (46.6%) were diagnosed with SAHS, defined by an apnea-hypopnea index greater than 10 in nighttime polysomnography. Comparison of the results obtained in both recordings revealed statistically significant correlations for all comparisons. The optimal cutoff in this population was a respiratory disturbance index of 13.7 or more, for which the area under the receiver operating characteristic curve was 87.5% (95% confidence interval, 74.2%-95.4%). The mean cost of home respiratory polygraphy in a patient with suspected SAHS was euro69, whereas that of polysomnography was euro179.
Conclusions: Home respiratory polygraphy is a reliable technique for the diagnosis of SAHS. Using this technique routinely in patients suspected of SAHS will be more economical than using nighttime polysomnography. Uncertain results must be verified by nighttime polysomnography.