Association between body mass index and in-hospital outcomes: Analysis of the nationwide inpatient database.

Abstract

Over one-third of American adults (36%) are obese and more than two-thirds (69%) are overweight. The impact of obesity on hospitalization outcomes is not well understood. To examine the association between body mass index (BMI) and overall, cancer, chronic obstructive pulmonary disease (COPD), asthma, and cardiovascular disease (CVD)-specific in-hospital mortality; postsurgical complications; and hospital length of stay (LOS). Cross-sectional study. Representative sample of US hospitals included in the Health Cost and Utilization Project Nationwide Inpatient Sample database. We obtained data for patients admitted with a primary diagnosis of cancer, COPD, asthma, and CVD. In-hospital mortality, postsurgical complications, and hospital LOS. A total of 800,417 patients were included in this analysis. A higher proportion of Blacks (26.8%; 12.5%) and Whites (23.3%; 8.7%) had BMI of 40 to 49.9 and ≥50, respectively, compared with Hispanics (20.4%; 7.3%). Compared with normal BMI patients, the odds of in-hospital mortality increased 3.6-fold (odds ratio [OR] 3.62, 95% confidence interval [CI]: 3.37-3.89) for preobese patients, 6.5-fold (OR: 6.52, 95% CI: 5.79-7.34) for patients with BMI: 30 to 31.9, 7.5-fold (OR: 7.57, 95% CI: 6.67-8.59) for patients with BMI: 34 to 35.9, and 1.6- fold (OR: 1.77, 95% CI: 1.56-1.79) for patients with BMI ≥ 50. Compared with normal BMI patients, preobese and overweight patients had shorter hospital stays (β preobese: -1.58, 95% CI: -1.63, -1.52); however, no clear trends were observed for postsurgical complications. The majority of hospitalized patients in this analysis had a BMI > 30, and higher BMI was associated with increased risk of mortality and longer hospital stay.