New York, June 5 : Researchers have claimed that the actual mortality rate of adults with critical illness from Covid-19 in the US is less than what was previously reported. The study, published in the journal Critical Care Medicine, also indicated that the mortality rate of critically ill Covid-19 patients who required mechanical ventilation is also lower than previously thought. For the results, the research team from the Emory University in the US, observed 217 critically ill patients 18 years and older from six Covid-19 designated intensive care units in three hospitals in Atlanta from March to April 2020. Compared to earlier reports of a 50 per cent mortality rate, the study revealed that the mortality rate of critically ill patients who required mechanical ventilation was only 35.7 per cent. According to the study authors, about 60 per cent of patients observed in the study survived to hospital discharge. The findings showed that 4.8 per cent of patients still on the ventilator at the time of the report. Mortality was significantly associated with older age, lower body mass index, chronic renal disease, and receipt of mechanical ventilation, vasopressors, renal replacement therapy, or vasodilator therapy. The authors noted that several considerations may have influenced the outcomes of the study including that all critically ill patients with Covid-19 in the hospital network were admitted to pre-existing ICUs that had adequate staffing ratios and equipment. "Our early experience indicates that many patients survive their critical illness," the authors concluded. /IANS