The need for weight estimation in children during emergency care is well understood, but there is an identical, but less well appreciated, need in adults [1]. There are many drugs that need to be scaled to weight in adults to avoid adverse events due to overdosing and treatment failure due to underdosing (e.g., thrombolytics, anticoagulants, and many cardiovascular medications). During emergency care it might not be possible to obtain a measured weight before administering weight-based medication [2]. Under these circumstances it is necessary to estimate weight to allow for drug dose calculations, fluid volume calculations, mechanical ventilation settings, and other weight-based interventions. In order to ensure the efficacy of the drug therapy, while avoiding harm from overdose, the weight estimation should be as accurate as possible [3]. Theoretically, the ideal method of weight estimation should be accurate, quick, and easy to use in the Emergency Department (ED), the Intensive Care Unit (ICU), or the prehospital environment. It should also, preferably, require minimal training for effective use, and be inexpensive [4].

Some of the methods of weight estimation that have been studied include estimates by patients themselves, estimates by patients' family members, estimates by healthcare providers, single variable, and multiple variable anthropometric formulas, automated computerized methods, as well as pediatric weight estimation methods cross-purposed to be applied in adults (e.g., the PAWPER XL-MAC tape and the Mercy method).

Weight measurement and estimation during emergency care has not been well researched in adults. This is epitomized by the lack of research on the use of in-bed or in-stretcher scales. These systems have never been validated during any form of clinical care, and the limited information that is available suggests that in-bed scales frequently cannot be used, and may be very inaccurate [5]. With regards to weight estimation, many of the methods that have been developed are not accurate or may not be well suited for clinical use, especially during emergency care. Information on the accuracy and usability of existing methods of adult weight estimation would, therefore, be useful for clinicians when considering this aspect of critical care [6].

The aim of this systematic review was to identify, review, analyze, and synthesize data from the existing published literature on the accuracy of methods of estimating weight in adults. The specific objectives were threefold: firstly, to identify relevant methods of weight estimation that have been studied in adults; secondly, to evaluate and compare the accuracy of these weight estimation methods; and, thirdly, to describe the potential suitability of these methods for use during emergency care.