For example, sepsis due to a primary pulmonary infection may be different than sepsis from infected pancreatic necrosis. Since there may be an interaction between disease etiology and intervention, stratified analyses are often performed but these increase the sample size needed to detect a treatment effect in each subgroup as well as the expense of the trial. Due to these issues, the need to evaluate the quality of clinical literature in critical care becomes paramount. Critical care is a relatively new specialty 7 . This, combined with the transdisciplinary nature of critical care and the imprecise definition of critical illness has lead to a poorly defined research agenda with the resultant lack of detailed knowledge about several clinical problems.
Critical care presents several unique challenges for clinical research.
To formulate a research question, an investigator must be able to define a patient population, treatment or intervention, and outcome. Operationalizing these variables especially a diseased patient population, for critical care clinical research is complex. Compare the investigator studying outcomes after myocardial infarction to one studying the same research question in sepsis. Myocardial infarction is a common disease that is readily diagnosed with several laboratory tests and thus it is easy to define a population of patients with the disease. Patients with myocardial infarction receive treatments that are relatively specific for the diagnosis and are generally cared for by cardiologists, internists or family physicians.