Perspective:

This database represents approximately 15% of all US hospital admissions and the study is a cohort of hospitalized adults, not outpatients. Most of these data are intuitive, but the mortality observation is a cause for speculation. Despite a higher rate of complications and comorbidities among those with OSA, there was a lower rate of mortality among those with OSA compared to those without OSA. Given their tendency for hypopnea and apnea, OSA patients would not tolerate desaturations associated with pneumonia. This might be one explanation why OSA patients would be more likely to exhibit respiratory failure earlier in their course, prompting mechanical ventilation. In contrast, those without OSA would likely have more severe complications of pneumonia, such as sepsis, to warrant intubation. An earlier clinical status change resulting in mechanical ventilation among OSA patients might avoid downstream complications, such as death. Last, obesity has been shown in other cohorts to have better outcomes due to earlier medical presentation and increased metabolic reserves. More study is needed to identify which factors are associated or lead to the paradox of OSA associated with higher complications, but lower mortality. Since the true percentage of OSA in this cohort is likely underestimated, the impact of OSA on complications from pneumonia may be overestimated or may simply apply to that group of OSA with severe enough disease to be diagnosed prior to hospital admission.