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  1. Outcomes research evaluates the effects of medical care and the health care process on individual and societal health.

  2. Outcomes research seeks to understand the effectiveness of an intervention rather than its efficacy. It is this focus, not the methodology employed, that differentiates outcomes research from traditional clinical research.

  3. Commonly used outcome measures include mortality, health status, cost, and quality measures.

  4. Although outcomes research is not defined by a specific methodology, outcomes researchers often utilize observational study designs and methods from the social sciences. The use of large administrative datasets is increasingly popular.

  5. The major limitations of observational studies are bias and confounding.

  6. Matching, stratification, multivariate analysis, propensity scores, and instrumental variables are tools used to adjust for confounding.

  7. Outcomes researchers in the intensive care unit face unique challenges due to the breadth of patients, diseases, therapies, providers, and health care delivery models used in critical care.


Since the Institute of Medicine (IOM) published its first report in the quality series, To Err is Human, in 1999, there has been increased awareness of the problems that face health care in the United States and an increased emphasis on improving the quality of care our patients receive.1 Outcomes research, which “studies the end results of medical care—the effect of the health care process on the health and well-being of patients and populations,”2 is one type of research used to study, understand, and improve health care quality. Outcomes research differs from more traditional medical research in its focus and endpoints; it seeks to understand the effectiveness of an intervention rather than its efficacy. Ultimately, the results of outcomes research can be used to benchmark performance, reduce adverse events, formulate clinical practice guidelines, and inform health policy decisions.3,4

In the critical care setting, outcomes research can be particularly impactful for several reasons. First, ICU patients are at a high risk of death and preventable harms due to the acuity of their illnesses and the frequency and complexity of interventions.5 Additionally, the costs of ICU care are substantial. ICU patients inhabit only 10% of inpatient beds, but account for almost a quarter of acute care hospital costs.6,7 In 2005, critical care costs in the United States totaled $81.7 billion per year—4.1% of national health expenditures and 0.66% of the gross national product.8 Furthermore, resource utilization varies significantly, but an association between increased expenditure and quality of care has not been clearly elucidated.9,10,11,12 Therefore, outcomes research in critical care has the potential to make ICU care better, safer, and more cost-effective.

This chapter describes the historical and theoretical basis for outcomes research, methods used by outcomes researchers, endpoints of outcomes research, and common challenges and limitations.


Florence Nightingale and ...

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