title: Reporting the methodology of height and weight acquisition in studies of body mass index-based prognosis in critically ill patients.
abstract: OBJECTIVE
  Conflicting findings were reported on the body mass index (BMI)-based prognosis of critically patients. Errors in source weight and height data can confound BMI group allocation. The aim of the present work was to examine investigators' reporting on the methods of height and weight acquisition (HWA).
  
  
  METHODS
  PubMed and Embase databases were searched for studies describing BMI group-based risk of death in critically ill patients. Eligible studies were examined for reporting on (1) the use of measured and/or estimated HWA, (2) details of measuring devices, (3) device accuracy, and (4) methods of adjustment for acute and chronic fluid-related weight changes.
  
  
  RESULTS
  Thirty studies met the eligibility criteria, including 159,565 patients. No data were provided in 13 studies (52% of reported patients) on whether estimates or measurements were used for HWA. Measured HWA was used exclusively in 6 studies (3% of patients), and an unspecified combination of estimated and/or measured HWA was reported for the remainder. Only 1 study reported the specific devices used. None of the studies provided data on the bias and precision of measuring devices. Adjustment for chronic and/or acute fluid-related weight changes was addressed in 2 studies for each.
  
  
  CONCLUSIONS
  These findings demonstrate the prevalent risk for BMI group misallocation in the reviewed studies, which may confound BMI-based prognosis, raising concerns about the validity of reported BMI-related prognostic impact.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Texas Tech University Health Sciences Center at the Permian Basin, Odessa, TX. Electronic address: lavi.oud@ttuhsc.edu.
authors.forename: Lavi
authors.initials: L
authors.lastname: Oud
mesh_terms: D000886:Anthropometry / Q000379:methods*; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D016638:Critical Illness; D006801:Humans; D011379:Prognosis
keywords: Body mass index; Critical illness; Mortality; Obesity