Home unattended vs hospital telemonitored polysomnography in suspected obstructive sleep apnea syndrome - A randomized crossover trial

Study objective: To compare home unattended polysomnography (HPSG) with polysomnography performed in a local hospital and telemonitored by a sleep laboratory (T-PSG) in the diagnosis of obstructive sleep apnea syndrome (OSAS). Design: Randomized crossover trial. Patients: Ninety-nine patients with suspected OSAS who underwent H-PSG and T-PSG on 2 consecutive nights, according to a randomized order. Measurements: H-PSG and T-PSG were compared in terms of (1) effectiveness, only recordings providing interpretable signals from at least one EEG, the electro-oculograph, the electromyograph, air flow, thoracic or abdominal movements, and arterial oxygen saturation for 180 min of sleep were considered to be effective; (2),patient preference assessed by a questionnaire; and (3) polysomnographic indexes and final interpretative results in patients for whom both recordings were legible. Results: Recordings were considered to be ineffective in 11.2% of T-PSG (95% confidence interval [CI], 4.9 to 17.4%) and in 23.4% of H-PSG (95% CI, 19.12 to 27.68%). Thermistor problems were the main cause of failure of H-PSG. Forty-one percent of patients preferred H-PSG, and 55% preferred T-PSG. H-PSG and T-PSG did not differ in terms of sleep and respiratory indexes in the 65 patients in whom both recordings were legible. H-PSG and T-PSG were concordant in 58 of 65 patients using a 10-event-per-hour apnea-hypopnea index cutoff value for the diagnosis of OSAS. Conclusions: T-PSG is clearly superior to H-PSG from a technical point of view and tends to be preferred by patients. The site of recording (home vs hospital) has no influence on polysomnographic indexes.