Background: Previous studies have suggested that the gender and/or age of a patient may influence clinical outcomes of critically ill patients. Our objective was to determine whether there are gender- and age-based differences in clinical outcomes for mechanically ventilated patients in intensive care units (ICUs).
Methods: We performed a multicentre retrospective study involving adult patients who were admitted to the ICU and received at least 24 hours of mechanical ventilation (MV). The patients were divided into two groups based on gender and, subsequently, further grouped based on gender and age < or ≥ 65 years. The primary outcome measure was hospital mortality. Secondary outcome measures included duration of MV, hospital and ICU lengths of stay (LOS), and ICU mortality.
Results: A total of 853 mechanically ventilated patients were evaluated. Of those, 63.2% were men and 61.5% were ≥ 65 years of age. The hospital mortality rate for men was significantly higher than for women (35.4% vs. 28.7%, respectively; p = 0.042) and this difference was most pronounced among older patients (age ≥ 65 years; p = 0.006), even though there were no significant differences between both genders in age, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, type of admitting ICU, or in the number of comorbidities. We also found that the ICU mortality rate was significantly higher for men than for women among older patients (p = 0.011). However, the hospital and ICU mortality rates did not differ significantly between younger women and men. The durations of MV, ICU LOS, and hospital LOS was significantly longer for men than for women among younger patients (p ≤ 0.013) but not among older patients. Multivariate logistic regression analysis revealed that gender was found to be independently associated with hospital mortality among the whole group of patients as well as older patients.
Conclusions: There were important gender- and age-based differences in outcomes among mechanically ventilated ICU patients. Our findings merit consideration when designing future clinical trials involving mechanically ventilated patients.