Differences between manual and automatic analysis in determining the severity of obstructive sleep apnea using home...

Home sleep apnea testing (HSAT) is a diagnostic measure for obstructive sleep apnea hypopnea syndrome (OSAHS) in moderate/high risk patients. Some HSAT companies contain automatic analysis (AA). However, guidelines recommend manual analysis (MA) despite the weak evidence for this recommendation.

Evaluate the concordance between AA and MA of HSAT to make either a diagnosis and severity classification.

We evaluated AA and MA of HSAT between 2015 and 2016. The study was a blind analysis reviewed by two physicians using currents recommendations. The differences between AA and MA were compared with single variable T analysis, inter-scorer agreement for diagnosis was evaluated with Cohen Kappa coefficient, correlation was examined using Tau-b Kendall, and Bland-Altman plot was constructed to analyze differences between AA and MA.

One hundred and ninety-eight patients were included. In our study, the mean age was 50 ± 15 years, 83% male, BMI 30 ± 5 and neck circumference 41 ± 4 cm. Eighty-two percent of subjects showed an apnea-hypopnea index (AHI) > 5 ev/h. Thirty-five percent of patients with OSAHS were mild (AHI: 5-15 ev/h), 34% moderate and 31% severe (>30 ev/h). The kappa coefficient between physicians was 1.0 (high), between AA and MA was 0.58 (moderate) for the diagnosis of OSAHS and 0.33 (weak) for severity with 0.70 Tau-b. The AA underestimates the IAH -8 ev/h, (95% CI -9 to -7 ev/h, p < 0.001) and delivers a misclassification of severity by 47%.

AA underestimates the rate of respiratory events and alters the classification of the severity of the disease and may modify the therapeutic approach.