Characteristics of Hospital Stays Involving Malnutrition

HCUP Statistical Brief, No. 210

Undernutrition is a form of malnutrition characterized by a lack of adequate calories, protein, or other nutrients needed for tissue maintenance and repair. Malnutrition (undernutrition) occurs among approximately 3 percent of adult hospital inpatient stays in the United States and is associated with increased morbidity, mortality, and health care costs. Adult hospitalizations with a diagnosis of malnutrition have a longer length of stay, higher costs, more comorbidities, and 5 times the likelihood of death, compared with other adult hospital stays.

Evidence suggests that early nutritional intervention may reduce complication rates, mortality, and resource use associated with malnutrition. However, many cases of malnutrition are unrecognized and untreated. Clinical definitions of malnutrition and the set of diagnostic codes used to identify malnutrition in hospital administrative data have varied. Malnutrition may result from chronic starvation and conditions such as anorexia, but it also may be a consequence of acute and chronic illness or injury.

Characteristics of Hospital Stays Involving Malnutrition, a statistical brief from the Healthcare Cost and Utilization Project (HCUP), presents national estimates on the characteristics of malnutrition reported during nonmaternal and nonneonatal hospital inpatient stays in 2013.

Malnutrition was identified using a broad set of diagnostic codes that included the following six categories:

  • Postsurgical nonabsorption.
  • Nutritional neglect.
  • Cachexia.
  • Protein-calorie malnutrition.
  • Weight loss or failure to thrive.
  • Underweight.


  • In 2013, there were nearly 2 million hospital inpatient stays involving malnutrition. The most common type was protein-calorie malnutrition (63.9 percent of all malnutrition stays), accounting for 4.5 percent of all inpatient stays, and 9.1 percent of aggregate costs (nonmaternal and nonneonatal only).
  • Other malnutrition-related stays were for weight loss or failure to thrive (21.6 percent of all malnutrition stays), cachexia (8.3 percent), underweight (4.4 percent), postsurgical nonabsorption (1.7 percent), and nutritional neglect (0.1 percent).
  • Patients with malnutrition tended to be older (especially 85 years or older), black, and from low income, and rural areas.
  • Compared with other types of malnutrition, in-hospital mortality was higher for stays with cachexia (11.7 percent died in the hospital) and protein-calorie malnutrition (8.4 percent)—4 to 5 times the in-hospital death rate of all nonmaternal, nonneonatal stays (2.4 percent).
  • Average hospital costs were higher for stays involving protein-calorie malnutrition ($25,200) and postsurgical nonabsorption ($23,000) than for other malnutrition stays.
  • Principal diagnoses varied by type of malnutrition: medical, surgical, or device complications were common for postsurgical nonabsorption; injuries and conditions due to external causes were common for nutritional neglect. Septicemia was common among all types of malnutrition.

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Page last reviewed September 2016
Internet Citation: Characteristics of Hospital Stays Involving Malnutrition. Content last reviewed September 2016. Agency for Healthcare Research and Quality, Rockville, MD.