Nutritional parameters associated with prolonged hospital stay among ambulatory adult patients

Background

Comprehensive evaluations of the nutritional parameters associated with length of hospital stay are lacking. We investigated the association between malnutrition and length of hospital stay in a cohort of ambulatory adult patients.

Methods

From September 2006 to June 2009, we systematically evaluated 1274 ambulatory adult patients admitted to hospital for medical or surgical treatment. We evaluated the associations between malnutrition and prolonged hospital stay (> 17 days [> 75th percentile of distribution]) using multivariable log-linear models adjusted for several potential nutritional and clinical confounders recorded at admission and collected during and at the end of the hospital stay.

Results

Nutritional factors associated with a prolonged hospital stay were a Nutritional Risk Index score of less than 97.5 (relative risk [RR] 1.64, 95% confidence interval [CI] 1.31–2.06) and an in-hospital weight loss of 5% or greater (RR 1.60, 95% CI 1.30–1.97). Sensitivity analysis of data for patients discharged alive and who had a length of stay of at least three days (n = 1073) produced similar findings (adjusted RR 1.51, 95% CI 1.20–1.89, for Nutritional Risk Index score < 97.5). A significant association was also found with in-hospital starvation of three or more days (RR 1.14, 95% CI 1.01–1.28).

Interpretation

Nutritional risk at admission was strongly associated with a prolonged hospital stay among ambulatory adult patients. Another factor associated with length of stay was worsening nutritional status during the hospital stay, whose cause–effect relationship with length of stay should be clarified in intervention trials. Clinicians need to be aware of the impact of malnutrition and of the potential role of worsening nutritional status in prolonging hospital stay.Choosing the most appropriate approach to clinical management for patients admitted to hospital may not only improve clinical outcomes but also result in early discharge.^1–4 Several factors associated with prolonged hospital stay include the clinical setting, the type and the severity of disease, the presence of comorbidities, the quality and number of interventions, and the patient’s age.^5,6 There is a growing body of evidence that nutritional factors, both related and unrelated to the leading diseases, also affect length of hospital stay and overall health care costs.^7–11 A poor nutritional status at the time of admission can contribute to a prolonged hospital stay, and inadequate nutritional support may negatively affect both nutritional status and prognosis.^7,8 However, these factors have been frequently analyzed independently, and comprehensive and multivariable evaluations of the nutritional parameters associated with a prolonged hospital stay are lacking. Moreover, the potential effect of other confounders occurring during the hospital stay, such as worsening nutritional status, is unknown.We identified the nutritional parameters associated with prolonged hospital stay in a representative sample of ambulatory adult patients. We investigated the association between nutritional risk at the time of admission and length of stay after controlling for several confounders recorded at admission and during the hospital stay.