Multidimensional prognostic index (MPI) predicts non-invasive ventilation failure in older adults with acute respiratory failure

Background: Acute respiratory failure (ARF) is a very common complication among hospitalized older adults. Non-invasive ventilation (NIV) may avoid admission to intensive care units, intubation and their related complication, but still lacks specific indications in older adults. Multidimensional Prognostic Index (MPI) based on comprehensive geriatric assessment (CGA) could have a role in defining the short-term prognosis and the best candidates for NIV among older adults with ARF. Methods: This is a retrospective observational study which enrolled patients older than 70 years, consecutively admitted to an acute geriatric unit with ARF. A standardized CGA was used to calculate the MPI at admission. Multivariate Cox regression models were used to test if MPI score could predict in-hospital mortality and NIV failure. Receiver operator curve (ROC) analysis was used to identify the discriminatory power of MPI for NIV failure. Results: We enrolled 231 patients (88.2 ± 5.9 years, 47% females). Mean MPI at admission was 0.76±0.16. In-hospital mortality rate was 33.8%, with similar incidence in patients treated with and without NIV. Among NIV users (26.4%), NIV failure occurred in 39.3%. Higher MPI scores at admission significantly predicted in-hospital mortality (β=4.46, p<0.0001) among patients with ARF and NIV failure (β=7.82, p = 0.001) among NIV users. MPI showed good discriminatory power for NIV failure (area under the curve: 0.72, 95% CI: 0.58–0.85, p<0.001) with optimal cut-off at MPI value of 0.84. Conclusions: MPI at admission might be a useful tool to early detect patients more at risk of in-hospital death and NIV failure among older adults with ARF.