Background: although advancing age is associated with worse outcomes on mechanically ventilated elderly patients admitted to intensive care units (ICU), this relation has not been extensively investigated on patients not requiring invasive ventilatory support.
Objective: to determine the relationship between age and in-hospital mortality of elderly patients, admitted to ICU, requiring and not requiring invasive ventilatory support.
Design: prospective observational cohort study conducted over a period of 11 months.
Setting: medical-surgical ICU at a Brazilian university hospital.
Subjects: a total of 840 patients aged 55 years and older were admitted to ICU.
Methods: in-hospital death rates for patients requiring and not requiring invasive ventilatory support were compared across three successive age intervals (55-64; 65-74 and 75 or more years), adjusting for severity of illness using the Acute Physiologic Score.
Results: age was strongly correlated with mortality among the invasively ventilated subgroup of patients and the multivariate adjusted odds ratios increased progressively with every age increment (OR = 1.60, 95% CI = 1.01-2.54 for 65-74 years old and OR = 2.68, 95% CI = 1.58-4.56 for > or =75 years). For the patients not submitted to invasive ventilatory support, age was not independently associated with in-hospital mortality (OR = 2.28, 95% CI = 0.99-5.25 for 65-74 years old and OR = 1.95, 95% CI = 0.82-4.62 for > or =75 years old).
Conclusions: the combination of age and invasive mechanical ventilation is strongly associated with in-hospital mortality. Age should not be considered as a factor related to in-hospital mortality of elderly patients not requiring invasive ventilatory support in ICU.