To the Editor.
—The article by Carson et al1 strongly implies that care was better under the closed ICU system because of a nonsignificant trend in mortality. One could just as easily conclude otherwise; the mortality among patients requiring mechanical ventilation was higher (46.8% vs 34%) under the closed system. Intensive care unit nurses felt more comfortable working solely with dedicated ICU physician staff, but this is only to be expected and does not make a valid outcome measure. I suspect the greater mean APACHE II score of patients during the closed trial reflected reluctance among primary physicians to relinquish care of "borderline" patients to the ICU staff. One wonders if net hospital mortality did not increase among relatively sick patients kept in the regular medical units. Mandating the transfer of ICU patients to critical care specialists may improve short-term outcomes; as a primary care physician, I am well aware of my