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Age differences in survival outcomes and resource use for chronically critically ill patients

https://doi.org/10.1016/j.jcrc.2008.02.004Get rights and content

Abstract

Purpose

Chronically critically ill (CCI) patients use a disproportionate amount of resources, yet little research has examined outcomes for older CCI patients. The purpose of this study was to compare outcomes (mortality, disposition, posthospital resource use) between older (≥65 years) and middle-aged (45-64 years) patients who require more than 96 hours of mechanical ventilation while in the intensive care unit.

Methods

Data from 2 prospective studies were combined for the present examination. In-hospital as well as posthospital discharge data were obtained via chart abstraction and interviews.

Results

One thousand one hundred twenty-one subjects were enrolled; 62.4% (n = 700) were older. Older subjects had a 1.3 greater risk for overall mortality (from admission to 4 months posthospital discharge) than middle-aged subjects. The Acute Physiology Score (odds ratio [OR], 1.009), presence of diabetes (OR, 2.37), mechanical ventilation at discharge (OR, 3.17), and being older (OR, 2.20) were statistically significant predictors of death at 4 months postdischarge. Older subjects had significantly higher charges for home care services, although they spent less time at home (mean, 22.1 days) than middle-aged subjects (mean, 31.3 days) (P = .03).

Conclusion

Older subjects were at higher risk of overall mortality and used, on average, more postdischarge services per patient when compared with middle-aged subjects.

Introduction

The increase in health care costs in the United States has been well documented [1], [2] with 2006 expenditures for health care exceeding 2 trillion dollars [3]. Reasons cited as contributing to the rise in health care costs are the aging of the population, increases in severity of illness, and the growing number of chronically critically ill (CCI) patients [1], [4], [5]. Chronically critically ill patients are intensive care unit (ICU) patients who survive an initial period of life threatening illness but who remain dependent on the high technology services (especially mechanical ventilation) of the critical care unit [5]. This group of patients, while accounting for approximately 10% of ICU admissions, uses 25% to 40% of ICU resources with resulting high in-hospital mortality and continuing postdischarge morbidity [5], [6].

Although research has examined outcomes for CCI patients, little has focused on examining outcomes for older CCI patients. Although those aged 65 years and older comprise only 13% of the US population, they consume 36% of total US personal health care expenses [7]. As a result, the cost of health care expenditures for older adults has been predicted to reach $15 970 billion by the year 2030 [8]. In addition, the number of admissions for older patients has been rising with 25% to 50% of all admissions to ICUs being for older patients [9]. It is expected that the older CCI population will continue to grow and use a relatively large amount of resources.

The impact of age on in-hospital outcomes of ICU patients requiring prolonged mechanical ventilation has been examined [1], [10], [11], [12]. Studies that have included age-specific data for these patients have yielded mixed results regarding whether or not age has an impact on outcomes after mechanical ventilation [8], [10], [13], [14], [15]. Prior research has focused primarily on the impact of age upon in-hospital outcomes, and there is a need to examine posthospital discharge outcomes to more fully assess the impact of age upon outcomes [1], [14].

The primary purpose of our study was to examine the relationship between age and in-hospital and posthospital outcomes for older CCI patients. Specifically, we were interested in comparing outcomes (mortality, disposition, posthospital resource use) between patients ≥65 years of age (older) and patients ages 45 to 64 years (middle-aged) who require more than 96 hours of mechanical ventilation while in the ICU.

We were interested in comparing these 2 age groups to more fully understand the outcomes of older subjects as they related to a comparison group of middle-aged subjects. Traditionally, research examining the impact of age upon outcomes for CCI patients has dichotomized age as older (≥65 or ≥75 years) and younger (<65 or <75 years). It has been argued that to use a cohort group whose ages range from 18 to 64 years as a comparison group is not ideal [16], and it has been recommended that older and middle-aged adult age groups be used for analysis and comparisons [16], [17]. To date, no one has used the middle-aged group as a comparison group for older CCI patients.

There is no precise definition of “prolonged mechanical ventilation” (PMV) [12]. Some define PMV based on Diagnosis Related Groups (DRG) categories focused on mechanical ventilatory support (DRG 475, 483, 541), whereas others define it using International Classification of Diseases, Ninth Edition (ICD-9) codes that include patients who have received 5 days or more of mechanical ventilation. The National Association for Medical Direction of Respiratory Care has recommended that PMV be defined as the need for 21 or more consecutive days of mechanical ventilation for 6 hours per day or more. In both of our studies, we chose the number of days of mechanical ventilation to define the subset of patients who we felt were “chronically critically ill.” Previous research has established that patients who require mechanical ventilation beyond 72 hours are at high risk of death or prolonged hospitalization with multiorgan dysfunction and continuing care needs beyond hospital discharge [10], [18].

For the present study, we used more than 96 continuous hours of mechanical ventilation in the ICU as eligibility criteria. We did so for several reasons. First, we wanted to include patients who did not follow the usual short stay pattern, many of whom died after 10 to 14 days in the ICU. Secondly, we felt that the more than 96-hour definition encompassed patients who were requiring a greater amount of time on mechanical ventilation and for whom decisions regarding use of health care resources and treatment goals would be of key importance. Finally, this criterion was consistent with the number of days associated with Medicare's definition of PMV and was felt to be more meaningful to clinicians.

Section snippets

Methods

For the purposes of this retrospective study, data from 2 large studies were combined. This was done to increase the sample size to increase confidence and generalizability of study results. Both studies used very similar eligibility and ineligibility criteria, and during the span of the 2 studies, key characteristics of the CCI population (eg, mortality and percentage of patients being discharged to home) had not changed. One aspect of clinical practice that did change over the course of the 2

Results

Fig. 1 shows the distribution of the total sample. The sample is similar to other samples of CCI patients in that their average age was 68.3, predominantly white, evenly divided between males and females, with most (86.8%) living independently before this hospitalization. As a group, they spent, on average, 19.9 days in the ICU and 14.3 days on mechanical ventilation. Of the 1121 subjects enrolled in-hospital, over one half were older (≥65 years of age) and over one third (48.9%) died

Discussion

It has been well documented that long-term outcomes of patients requiring prolonged mechanical ventilation are poor [10], [24], [25], [26] and that elderly patients who require PMV are at even greater risk for high mortality and morbidity [8], [9], [14]. Research on elderly CCI patients has focused primarily on in-hospital outcomes and such reports have lacked examination of posthospital outcomes for this vulnerable group of patients. In addition, prior research has primarily used all subjects

Acknowledgments

This study was funded by grants from the National Institute of Nursing Research (Bethesda, MD) (RO1-NR0-0527 and RO1-NR04318).

References (28)

  • E.W. Ely et al.

    Mechanical ventilation in a cohort of elderly patients admitted to an intensive care unit

    Ann Intern Med

    (1999)
  • A.A. El Solh et al.

    Overview of respiratory failure in older adults

    J Intensive Care Med

    (2006)
  • A. Combes et al.

    Morbidity, mortality, and quality-of-life outcomes of patients requiring > or =14 days of mechanical ventilation

    Crit Care Med

    (2003)
  • L. Chelluri et al.

    Long-term mortality and quality of life after prolonged mechanical ventilation

    Crit Care Med

    (2004)
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