In reply: Outcomes difference in non-invasive ventilation in 'very old' patients with acute respiratory failure: Occult gender effect?

In our cohort, the female/male ratio in very old patients was 3:1, and although women were older (88.5±3 vs 86.2±1.6 years, p=0.0065), this did not imply an increased mortality after NIV (χ2=47.74; p=0.8553).Another interesting point raised by Tibullo and Esquinas is the effect of comorbidities in ventilated patients. It is known that comorbidities influence the outcome of ventilated patients, and a Charlson Comorbidity Index ≥3 has been shown to be an independent risk factor for in-hospital mortality.6 In our patients older than 85 years, Charlson Comorbidity Index was not statistically different from that of the younger group (3.52±1.57 vs 3.±2.11). This could explain, at least in part, the lack of differences in the outcomes of the two populations.