Association of Injury Factors, Not Body Mass Index, With Hospital Resource Usage in Trauma Patients.

Background: Allocating resources appropriately requires knowing whether obese patients use more resources during a hospital stay than nonobese patients.

Objectives: To determine if trauma patients with different body mass indexes differed in use of resources measured as a multifaceted outcome variable.

Methods: A trauma registry was used for a retrospective study of adult patients admitted to a midwestern level I trauma center. Patients were stratified into 3 groups: nonobese (normal weight, overweight), obese, and morbidly obese. Three canonical correlation analyses were used to determine the relationship between patient/injury characteristics and hospital resource usage.

Results: In a sample of 9771 patients, 71.2% were non-obese, 23.8% obese, and 5.0% morbidly obese. For patient/injury characteristics, Injury Severity Score and physiological complications were significant variables for all 3 groups. Scores on the Glasgow Coma Scale were significant for nonobese patients only. For resource usage, intensive care unit length of stay and procedures were significant variables for all 3 groups.

Conclusions: Associations between body mass index and outcomes have been noted when assessed as independent variables. However, when resource usage was assessed as a multifaceted outcome variable, injury factors (higher Injury Severity Score, lower scores on the Glasgow Coma Scale, more physiological complications) were associated with resource usage (increased length of stay in the intensive care unit and increased number of procedures). These findings provide clinicians a new perspective for evaluating the complex relationship between patient/injury characteristics and hospital resource usage.