A new renal inpatient nutrition screening tool (Renal iNUT): a multicenter validation study

Screening of patients with renal disease for malnutrition risk on hospital admission provides an opportunity to improve prognosis. This study aimed to assess the validity and reliability of the Renal iNUT, a novel renal-specific inpatient nutrition screening tool.

Adult inpatient admissions to three renal units were screened using the Renal Inpatient Nutrition Screening Tool (iNUT) and the generic Malnutrition Universal Screening Tool (MUST) and compared against nutritional status using Subjective Global Assessment (SGA) as the standard. Construct validity was assessed by Handgrip Strength (HGS), reliability by repeated iNUT administration and nurse opinion by questionnaire.

Of 141 admissions, 45% were malnourished (SGA score B or C). Using iNUT, 49% patients had increased malnutrition risk (score ≥1), 35.5% requiring dietetic referral (score ≥2). MUST indicated 20% at increased malnutrition risk and dietetic referral in 7%. iNUT was more sensitive than MUST in identifying increased malnutrition risk (92.1% vs 44.4%) and dietetic referral (69.8% vs 15.9%). Specificity of iNUT for increased risk was 82.1% and 92.3% for dietetic referral. 47% patients had sarcopenic-range HGS, with significant difference between iNUT score ≥2 and 0 (p < 0.001). iNUT reliability assessed by kappa was 0.74 (95% CI, 0.58 to 0.9), indicating substantial agreement. Nurse evaluation (n = 71) was highly favorable.

The Renal iNUT is a valid and reliable nutrition screening tool when used by nurses admitting patients to specialist renal wards. In comparison with MUST, use of iNUT is likely to improve the identification of malnourished patients for nutritional intervention and dietetic referral.