Hospitalizations Involving an Intensive Care Unit Admission Among Patients Aged 65 Years and Older Within New York City Hospitals During 2000-2014.

Objective: To describe hospitalizations involving an intensive care unit (ICU) admission among patients aged 65 years and older within New York City (NYC) hospitals during 2000-2014. Design: Observational study using an all-payer hospital discharge dataset. Setting: The setting was in NYC hospitals. Patients: Patients aged 65 years and older admitted to an ICU within a NYC hospital during 2000-2014. Interventions: No interventions were carried out. Measurements and Main Results: We calculated the mean annual number of hospitalizations involving an ICU admission. We also examined characteristics of hospitalizations, including the occurrence of in-hospital death and principal diagnosis. There were 5,338,577 hospitalizations of patients aged >= 65 years within NYC hospitals during 2000-2014, of which 765,084 (14.3%) involved an ICU admission. The mean annual number of hospitalizations involving an ICU admission for this age group decreased from 57,938 during 2000-2002 to 45,785 during 2012-2014. The proportion of hospitalizations involving an ICU admission in which in-hospital death occurred decreased from 15.9% during 2000-2002 to 14.5% during 2012-2014. During 2000-2002, 11.6% of hospitalizations involving an ICU admission listed an "infectious" principal diagnosis, increasing to 20.7% during 2012-2014. Listing of a "cardiovascular" principal diagnosis decreased from 46.4% to 33.4% between these time periods. "Infectious" principal diagnoses accounted for 31.0% of all hospitalizations involving an ICU admission in which in-hospital death occurred during the entire study period, while "cardiovascular" principal diagnoses accounted for 21.3%. Conclusions: This investigation provides a clearer understanding of ICU utilization among patients aged 65 years and older in NYC. Ongoing monitoring is warranted given projections that the proportion of New Yorkers aged 65 years and older will increase in coming years. In particular, in light of the observed increase of infectious principal diagnoses during the study period, further investigation is needed into the role of infectious disease in causing critical illness in NYC.