Original scientific article
Estimated Height, Weight, and Body Mass Index: Implications for Research and Patient Safety

https://doi.org/10.1016/j.jamcollsurg.2006.08.018Get rights and content

Background

Research suggests that weight influences patient care and outcomes. Health-care providers (HCPs) sometimes rely on patient self-reports or HCP estimates of height and weight. The purpose of this study was to determine the accuracy of self-reported height and weight and HCP estimations of height, weight, and body mass index (BMI) classification when compared with measured height, weight, and calculated BMI.

Study design

Attending physicians, residents, and nurses provided height and weight estimates along with BMI categorizations for 110 trauma patients at a large, teaching hospital with a Level I trauma center. Patients provided reports of their heights and weights. Measured heights and weights were obtained with appropriate calibrated devices, and BMIs were calculated. Estimates and categorizations were then compared with measured and calculated values.

Results

HCPs were 41% and 53% accurate in estimating height and weight, respectively. Self-reports had higher accuracy (69% and 92%, respectively) but still resulted in a BMI misclassification of 32%. Twenty-two percent of patient self-reports were unobtainable. When HCPs attempted to categorize a patient into a BMI group, the accuracy was 56%. Functioning, calibrated instruments for measuring height and weight were frequently unavailable in relevant hospital locations.

Conclusions

This study demonstrated that HCPs’ estimates of height, weight, and BMI category are highly inaccurate. Patient self-reports are better, but are unavailable at times. Objective measurements with calibrated instruments are necessary for accuracy in research studies and for patient safety in clinical practice. Efforts to ensure the availability of calibrated instruments may be necessary in the hospital setting.

Section snippets

Methods

A prospective, descriptive study of HCP estimates of height and weight in a convenience sample of trauma patients was conducted between December 2004 and February 2005. Only nonpregnant patients aged 16 years or greater were eligible for enrollment. All trauma-code activation patients who were seen in the emergency department from 8:00 am to 5:00 pm, Monday through Friday, were included in the study.

An estimate of height, weight, and assignment to BMI category was obtained from the trauma

Results

One hundred ten patients were enrolled in the study. Seventeen patients were eliminated from analysis because of missing measured height or weight values. These patients either left the emergency department before being measured or had injuries, such as spinal column fractures, that precluded safe measurement with the available equipment. HCPs providing estimates included 8 attending physicians (2 to 21 estimates each), 16 resident physicians (1 to 12 estimates each), and 43 registered nurses

Discussion

It is common for health-care providers to either estimate or obtain family or self-reports of patient height and weight when measured height and weight are inconvenient or not readily obtainable. These estimates are frequently used to calculate nutrition and drug dosage or to assign patients to body habitus groups. This study was conducted as a preliminary step to conducting research on the impact of body habitus on trauma diagnosis and care. It was expected that although HCPs might not be able

Author Contributions

Study conception and design: Hendershot, Robinson, Roland, Vaziri, Rizzo, Fakhry

Acquisition of data: Hendershot, Robinson, Roland, Vaziri, Rizzo

Analysis and interpretation of data: Hendershot, Robinson, Rizzo, Fakhry

Drafting of manuscript: Hendershot, Fakhry

Critical revision: Hendershot, Robinson, Rizzo, Fakhry

Acknowledgment

We wish to express our gratitude to the attending physicians, residents, and nurses who participated by giving their height and weight estimations for this study.

References (7)

  • Centers for Disease Control. Prevalence of overweight and obesity among adults: United States, 1999–2000. Available at:...
  • H. Larkin

    Capital & candor: To meet the needs of obese patients, hospitals change processes, equipment and attitudes

    Hosp Health Netw

    (2004)
  • National Automotive Sampling System (NASS). Available at:...
There are more references available in the full text version of this article.

Cited by (0)

Competing Interests Declared: None.

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