Trends in short-term and 1-year mortality in very elderly intensive care patients in the Netherlands: a retrospective study from 2008 to 2014

Purpose: To describe the trends in short-term and long-term mortality in very elderly intensive care unit (ICU) patients between 2008 and 2014.

Methods: A retrospective cohort study was conducted using data from the National Intensive Care Evaluation Foundation from 31 Dutch ICUs. Generalized linear mixed-effects models were used to determine the change in adjusted short-term mortality (ICU/hospital deaths) and long-term mortality (3, 6, and 12 months after ICU admission) over the period 2008-2014 in very elderly patients and in patients less than 80 years old admitted to the ICU.

Results: A total of 216,196 patients admitted to 31 ICUs in the period from 2008 to 2014 were included in the study, including 28,284 (13.1%) very elderly patients (80 years or older). Follow-up data for determination of 3-, 6-, and 12-month mortality were available for, respectively, 210,005 (97.1%), 202,551 (93.7%), and 176,847 (81.8%) ICU admissions. The crude ICU and in-hospital mortality decreased, respectively, from 17.6% to 13.0% and from 30.7% to 21.0%. The annual risk-adjusted ICU and in-hospital mortality of very elderly patients (adjusted for APACHE III score, comorbidities, and admission type) decreased significantly during the study period [adjusted odds ratio 0.97 (0.95-0.99) and 0.92 (0.91-0.93), respectively]. Additionally, the annual risk-adjusted 3-, 6-, and 12-month mortality decreased significantly from 2008 to 2014 [adjusted odds ratio 0.96 (0.95-0.97), 0.96 (0.94-0.97), and 0.97 (0.95-0.98), respectively]. A similar significant annual decrease in risk-adjusted short-term and long-term mortality was observed in patients aged less than 80 years.

Conclusions: Both short-term and long-term risk-adjusted mortality decreased significantly during the study period in both very elderly ICU patients and patients aged less than 80 years in the Netherlands. This study clearly shows that in our setting very elderly patients benefit almost as much as their younger counterparts from improvement in quality of care over time.