The National Hospital Ambulatory Medical Care Survey is a massive database of abstracted patient records, systematically generated to produce a representative sample of the nation's Emergency Department visits.
It should come as no surprise that retrospectively abstracted data from the electronic medical record sometimes fails to accurately reflect patient care. The important question, however, is "how often?" This review of NHAMCS by one of the Annals editors looked at a measurement that ought to be pretty obvious – intubation. If you can't figure out whether a patient has been intubated via chart review, there's some serious issues with your data sourcing. However, in this review of NHAMCS, the author interprets up to one in four charts as being potentially inaccurate due to inconsistencies between documented intubation and the final disposition of the patient (e.g., non-ICU settings, home, observation status, etc.)
Now, there are some instances in which patients are intubated in the Emergency Department – yet not subsequently dispositioned to a critical care or morgue – but these "temporary" intubations certainly do not constitute 25% of intubations. The author goes on to note that Annals publishes a NHAMCS study at least twice a year – relatively influential towards practice given the Impact Factor – and the flaws in this data should limit the relative weighting of its importance.
"Congruence of Disposition After Emergency Department Intubation in the National Hospital Ambulatory Medical Care Survey"