Although the use of noninvasive ventilation and continuous positive airway pressure (CPAP) appear to exhibit similar long-term effectiveness in stable patients with obesity hypoventilation syndrome, CPAP is thought to be the preferred first-line treatment modality because of its lower complexity and cost, according to study results published in Lancet.
Investigators sought to determine the long-term comparative efficacy of both therapeutic modalities in a multicenter open-label randomized controlled study (ClinicalTrials.gov Identifier: NCT01405976) conducted at 16 clinical sites in Spain. Patients between the ages of 15 and 30 years with untreated obesity hypoventilation syndrome and an apnea-hypopnea index of ≥30 events per hour were enrolled in the study. All participants were randomly assigned to receive treatment with either noninvasive ventilation or CPAP. Both the investigators and the patients were informed of the treatment allocation. The primary study outcome was the number of hospitalization days per year. The analysis was conducted according to the intention-to-treat principle.
Between May 4, 2009, and March 25, 2013, a total of 100 patients were randomly assigned to the noninvasive ventilation group and 115 to the CPAP group (97 and 107, respectively, were included in the analysis). The median follow-up was 5.44 years in all participants; 5.37 years in participants in the CPAP group and 5.55 years in participants in the noninvasive ventilation group.
The mean number of hospitalization days per patient-year was 1.63 days in the CPAP group and 1.44 days in the noninvasive ventilation group (adjusted rate ratio, 0.78; 95% CI, 0.34-1.77; P =.561), indicating that hospital resource utilization was similar in both groups. Moreover, the following parameters were similar in both groups: incidence of cardiovascular events, blood pressure readings, mortality, arterial blood gases, spirometric data, quality of life, and occurrence of side effects.
A major study limitation is the primary outcome of hospitalization for any cause (eg, a marker of healthcare resource utilization) because when the study was designed in 2007, this was the only long-term outcome available in the literature. Patients with obesity hypoventilation syndrome have multiple comorbidities, and the use of CPAP therapy could potentially improve these comorbidities and lead to a reduction in the number of hospitalization days.
The investigators concluded that although the use of CPAP therapy has been shown to be less expensive than noninvasive ventilation and thus might be the preferred mode of treatment for individuals with obesity hypoventilation syndrome and severe sleep apnea, they recommend a case-by-case assessment of all patients until more studies become available.
Masa JF, Mokhlesi B, Benítez I, et al; on behalf of the Spanish Sleep Network. Long-term clinical effectiveness of continuous positive airway pressure therapy versus non-invasive ventilation therapy in patients with obesity hypoventilation syndrome: a multicentre, open-label, randomised controlled trial [published online March 29, 2019]. Lancet. doi:10.1016/S0140-6736(18)32978-7