Incidence of Malnutrition in Polymorbid Patients
Polymorbid medical inpatients have a malnutrition prevalence of approximately 40-50% in hospitalized populations at tertiary care centers, making this an extremely common and clinically significant problem that directly impacts mortality, morbidity, and quality of life. 1
Prevalence Data from High-Quality Evidence
The 2024 ESPEN guideline on nutritional support for polymorbid medical inpatients provides the most robust and recent data on this population:
Several prospective cohort studies consistently demonstrate a prevalence of approximately 40-50% in hospitalized polymorbid populations at tertiary centers. 1
When using validated screening tools like NRS-2002,83% of chronic patients with complex needs were found to be at nutritional risk. 2
When using the Mini Nutritional Assessment (MNA), 86% of polymorbid patients were either at nutritional risk or already malnourished. 2
The prevalence of nutritional risk measured by NRS-2002 significantly increases within just two weeks after admission (from 40.61% to 48.93%; p = 0.036), indicating that malnutrition worsens during hospitalization if not addressed. 1
Clinical Impact on Outcomes
The high incidence of malnutrition in polymorbid patients has profound consequences for morbidity, mortality, and quality of life:
Malnourished polymorbid patients have 2.38 times higher odds of hospital length of stay ≥3 days (95% CI, 1.45 to 3.88; p < 0.001). 1
Malnourished polymorbid patients have 2.28 times higher odds of readmission within 30 days (95% CI, 1.26 to 4.12; p < 0.006). 1
Mortality during admission is significantly higher in malnourished polymorbid patients (16.7% vs 1.6%, p < 0.01). 2
Five-month mortality is dramatically elevated in malnourished polymorbid patients (30.5% vs 9.8%, p < 0.01), with malnutrition being the sole independent predictor of mortality at 5 months. 2
Malnourished patients have a greater need for home care or intermediate care hospital placement at discharge (41.8% vs 22.9%, p < 0.01). 2
Historical Context and Broader Data
While the most recent and highest quality data comes from the 2024 ESPEN guideline, older studies provide additional context:
In studies involving more than 1,327 hospitalized adult patients, 40% to 55% were found to be either malnourished or at risk for malnutrition, with up to 12% being severely malnourished. 3
Hospital charges are reported to be 35% to 75% higher for malnourished patients compared to well-nourished patients. 3
Critical Clinical Implications
Universal screening for malnutrition risk at hospital admission using validated tools (NRS-2002 or MNA-SF) is essential given this 40-50% prevalence, as early identification and intervention directly reduces mortality, complications, and hospital readmissions. 1, 4
The remarkably high prevalence in this population—affecting nearly half of all polymorbid medical inpatients—combined with the severe impact on mortality and morbidity, makes malnutrition screening and intervention a critical priority that should be part of routine clinical care for all polymorbid hospitalized patients. 1, 5, 6