title: Study protocol: The Improving Care of Acute Lung Injury Patients (ICAP) study.
abstract: BACKGROUND
  The short-term mortality benefit of lower tidal volume ventilation (LTVV) for patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) has been demonstrated in a large, multi-center randomized trial. However, the impact of LTVV and other critical care therapies on the longer-term outcomes of ALI/ARDS survivors remains uncertain. The Improving Care of ALI Patients (ICAP) study is a multi-site, prospective cohort study that aims to evaluate the longer-term outcomes of ALI/ARDS survivors with a particular focus on the effect of LTVV and other critical care therapies.
  
  
  METHODS
  Consecutive mechanically ventilated ALI/ARDS patients from 11 intensive care units (ICUs) at four hospitals in the city of Baltimore, MD, USA, will be enrolled in a prospective cohort study. Exposures (patient-based, clinical management, and ICU organizational) will be comprehensively collected both at baseline and throughout patients' ICU stay. Outcomes, including mortality, organ impairment, functional status, and quality of life, will be assessed with the use of standardized surveys and testing at 3, 6, 12, and 24 months after ALI/ARDS diagnosis. A multi-faceted retention strategy will be used to minimize participant loss to follow-up.
  
  
  RESULTS
  On the basis of the historical incidence of ALI/ARDS at the study sites, we expect to enroll 520 patients over two years. This projected sample size is more than double that of any published study of long-term outcomes in ALI/ARDS survivors, providing 86% power to detect a relative mortality hazard of 0.70 in patients receiving higher versus lower exposure to LTVV. The projected sample size also provides sufficient power to evaluate the association between a variety of other exposure and outcome variables, including quality of life.
  
  
  CONCLUSIONS
  The ICAP study is a novel, prospective cohort study that will build on previous critical care research to improve our understanding of the longer-term impact of ALI/ARDS, LTVV and other aspects of critical care management. Given the paucity of information about the impact of interventions on long-term outcomes for survivors of critical illness, this study can provide important information to inform clinical practice.
authors.affiliation: Johns Hopkins University, 5th floor, 1830 East Monument Street, Baltimore, MD 21205, USA. dale.needham@utoronto.ca
authors.forename: Dale M
authors.initials: DM
authors.lastname: Needham
authors.forename: Cheryl R
authors.initials: CR
authors.lastname: Dennison
authors.forename: David W
authors.initials: DW
authors.lastname: Dowdy
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Mendez-Tellez
authors.forename: Nancy
authors.initials: N
authors.lastname: Ciesla
authors.forename: Sanjay V
authors.initials: SV
authors.lastname: Desai
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sevransky
authors.forename: Carl
authors.initials: C
authors.lastname: Shanholtz
authors.forename: Daniel
authors.initials: D
authors.lastname: Scharfstein
authors.forename: Margaret S
authors.initials: MS
authors.lastname: Herridge
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Pronovost
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003422:Critical Care / Q000592:standards*; D016638:Critical Illness; D003679:Deglutition; D006801:Humans; D008017:Life Expectancy; D018579:Patient Selection; D011446:Prospective Studies; D011788:Quality of Life; D012121:Respiration, Artificial / Q000592:standards*; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D016896:Treatment Outcome