Trends in Severity of Illness on ICU Admission and Mortality among the Elderly

Abstract

BackgroundThere is an increase in admission rate for elderly patients to the ICU. Mortality rates are lower when more liberal ICU admission threshold are compared to more restrictive threshold. We sought to describe the temporal trends in elderly admissions and outcomes in a tertiary hospital before and after the addition of an 8-bed medical ICU.MethodsWe conducted a retrospective analysis of a comprehensive longitudinal ICU database, from a large tertiary medical center, examining trends in patients’ characteristics, severity of illness, intensity of care and mortality rates over the years 2001–2008. The study population consisted of elderly patients and the primary endpoints were 28 day and one year mortality from ICU admission.ResultsBetween the years 2001 and 2008, 7,265 elderly patients had 8,916 admissions to ICU. The rate of admission to the ICU increased by 5.6% per year. After an eight bed MICU was added, the severity of disease on ICU admission dropped significantly and crude mortality rates decreased thereafter. Adjusting for severity of disease on presentation, there was a decreased mortality at 28- days but no improvement in one- year survival rates for elderly patient admitted to the ICU over the years of observation. Hospital mortality rates have been unchanged from 2001 through 2008.ConclusionIn a high capacity ICU bed hospital, there was a temporal decrease in severity of disease on ICU admission, more so after the addition of additional medical ICU beds. While crude mortality rates decreased over the study period, adjusted one-year survival in ICU survivors did not change with the addition of ICU beds. These findings suggest that outcome in critically ill elderly patients may not be influenced by ICU admission. Adding additional ICU beds to deal with the increasing age of the population may therefore not be effective.

The status of intensive care medicine research and a future agenda for very old patients in the ICU

“…Yet, there currently is no robust or validated clinical prediction tool that is able to reliably indicate the VOP who will substantially benefit from ICU care. Evidently, survival chances of VOPs are highly variable [6,20,44]. Substantially more data is required to be able to answer these questions if we want to improve the consistency and accuracy of admission decisions concerning VOPs.…”

Level of acuity, severity and intensity of care of adults and older adults admitted to the Intensive Care Unit

“…Since the ICU is a place intended for caring of patients who present or may present some degree of organic dysfunction (1) , it is expected that the severity of these patients is much higher than that observed in patients in the other wards. The higher severity has been previously described as associated with higher ICU mortality (2,8,10) .…”

“…In addition, the admission severity was not as high in the sample as a whole. A recent study which examined 19,510 ICU admissions (45.7% of older adults) between 2001 and 2008 showed that patients' severity at admission decreased over the years (2) . Greater access to ICU beds may have interfered in this reduction, considering that the greater availability of beds implies the admission of individuals with lower severity.…”

“…It is a fact that population aging (considered a worldwide phenomenon) has increased the number of older adults in intensive care (2,11,(25)(26)(27)(28) . The results showed that almost half of the sample consisted of older adults, which is in agreement with other studies that found a similar frequency in the proportion of older adults in the ICU (2,12,19,(25)(26)(27)(28) . It is expected that this frequency will continue to increase as the number of older adults increases in the different populations.…”

“…Several factors contribute to this increase such as population aging and technological advances which favor the occurrence of therapeutic approaches associated with an increased risk of complications (1) . An increase of 5.6% per year in the ICU admission rate among older adults was estimated between 2001 and 2008 (2) , not only showing the increase in occupation, but also the change in profile.…”