SNAQ (Short Nutritional Assessment Questionnaire)
- Ask each of the three questions verbatim. The patient answers Yes or No.
- Assign weights: Q1 Yes = 3 pts; Q2 Yes = 2 pts; Q3 Yes = 1 pt. All "No" answers = 0.
- Sum the three values. Possible range: 0–6.
- Interpret: 0–1 = not malnourished; 2 = moderate risk (dietary counseling); ≥3 = severe risk (immediate intervention).
- Complete in under 2 minutes at triage or during nursing assessment.
MIS (Malnutrition-Inflammation Score)
- Obtain dry weight history from the dialysis log or clinic chart for item 1.
- Assess dietary intake by direct interview using 24-hour recall or food frequency (item 2).
- Review GI symptoms over the past two weeks (item 3).
- Assess functional status using ADL history (item 4).
- Record comorbidities and dialysis vintage for item 5.
- Perform physical examination for subcutaneous fat (item 6) and muscle wasting (item 7).
- Calculate BMI from height and post-dialysis dry weight (item 8).
- Use the most recent serum albumin and TIBC from the laboratory (items 9 and 10).
- Sum all 10 items (each scored 0–3). Total range: 0–30.
SGA (Subjective Global Assessment)
- Gather weight history for the past 6 months and the 2-week trend (section A).
- Assess current dietary intake versus usual (section B).
- Ask about persistent GI symptoms lasting ≥2 weeks (section C).
- Determine functional capacity — whether the patient works normally, has reduced activity, or is largely bedbound (section D).
- Examine for subcutaneous fat loss at the triceps and periorbital area; note any muscle wasting at the temples, clavicle, and quadriceps; and assess for edema or ascites (section E).
- Synthesize all five domains and assign a global rating: A (well nourished), B (mild-to-moderate PEW), or C (severe PEW). The global rating reflects clinical judgment across all components — no formula is used.
When to Use
Routine Screening Indications
- All CKD Stage 3–5 patients at clinic enrollment and every 3–6 months thereafter
- All maintenance hemodialysis or peritoneal dialysis patients — monthly for MIS, quarterly for SGA
- Any patient with unintentional weight loss, reduced appetite, or new hospitalization
- Pre-transplant evaluation to identify nutrition-related risk factors
Limitations and Context
- SNAQ was validated in hospitalized general medical patients and adapted for CKD — use as a rapid flag, not a definitive assessment
- MIS was validated in maintenance hemodialysis patients; applicability to CKD stages 3–4 and peritoneal dialysis is extrapolated
- SGA requires clinician administration and rater training; inter-rater variability exists without standardized training
- Serum albumin (MIS item 9) is an acute-phase reactant — inflammation, not malnutrition alone, lowers it
- These tools screen and track; a full dietitian assessment is required for intervention planning
Protein-energy wasting (PEW) affects 28–54% of CKD patients and up to 75% of those on maintenance hemodialysis. Early identification using validated screening tools enables timely dietary intervention, oral nutritional supplementation, and optimization of dialysis adequacy before severe wasting occurs. Mortality risk rises sharply with MIS >6 and SGA rating B or C.
Pearls & Pitfalls
Paired Use: MIS + SGA
Combining MIS and SGA increases diagnostic accuracy. Use MIS for monthly trend monitoring and objective scoring; use SGA for semi-annual clinician-administered assessment. Discordance between the two prompts a deeper investigation for occult inflammation or fluid overload masking true nutritional status.
Albumin Interpretation in Dialysis Patients
Serum albumin is a negative acute-phase reactant. In the setting of infection, surgical stress, or fluid overload, albumin may fall independent of nutritional status. An MIS score elevated primarily through items 9 (albumin) and 10 (TIBC) in a patient with normal physical exam and stable weight may reflect inflammation rather than true PEW. Address the inflammatory trigger before escalating nutritional support.
Dialysis Adequacy and Nutrition Are Linked
Inadequate dialysis (Kt/V <1.2 for HD, Kt <1.7 for PD) causes uremic anorexia, which drives dietary protein intake below target. Before escalating nutritional support in a dialysis patient with PEW, verify and optimize dialysis adequacy. Increasing session frequency or duration often improves appetite and nutritional intake without any dietary change.
Obesity Does Not Exclude PEW
Patients with high BMI may still have significant muscle wasting (sarcopenic obesity). Do not rely on BMI alone to exclude PEW. A normal or high MIS item 8 (BMI) can coexist with high scores on items 6 (fat loss) and 7 (muscle wasting). Clinical examination and functional assessment are essential.
Oral Nutritional Supplements (ONS) First
For MIS 6–10 or SGA-B, the first-line intervention is optimization of oral dietary intake with dietitian counseling and renal-specific ONS (high-protein, phosphorus- and potassium-controlled formulas). IDPN is reserved for patients unable to meet ≥50% of their needs orally despite adequate counseling. Enteral and parenteral routes are used only when the GI tract is non-functional or inaccessible.
Nutrition Screening Calculator
Enter patient demographics, then select a tool tab. Results appear automatically after all fields are completed (SNAQ, MIS) or after selecting a global rating (SGA). All data remain in the browser — nothing is transmitted.
Reference: Kruizenga HM et al. Clin Nutr 2005;24(1):75–82. SNAQ validated for hospitalized patients; adapted for CKD screening.
Reference: Kalantar-Zadeh K et al. Am J Kidney Dis 2001;38(6):1251–1263. MIS validated for maintenance hemodialysis patients. Score range 0–30.
References: Detsky AS et al. JPEN J Parenter Enteral Nutr 1987;11(1):8–13. Steiber A et al. J Ren Nutr 2004;14(1):1–7 (CKD validation).
Next Steps
Use the result to support — not replace — clinical judgment.
- Interpret the value against the targets shown in the calculator and the Evidence section below, in the context of the full clinical picture.
- Trend serial measurements rather than acting on a single result; confirm abnormal or unexpected values before changing management.
- Apply the relevant KDIGO / specialty-guideline threshold and document the indication.
- Escalate or refer to nephrology when results are out of range, rapidly changing, or discordant with the clinical picture — and discuss the implications with the patient.
Evidence & References
Formula & Equations
SNAQ Score (range 0–6)
| Score | Category | Action |
|---|---|---|
| 0–1 | Not Malnourished | Routine monitoring; re-screen monthly or if condition changes |
| 2 | Moderate Risk | Dietary counseling; individualized nutritional plan |
| 3–6 | Severe Risk | Immediate nutrition support; consider ONS or IDPN if on dialysis |
MIS Score (range 0–30)
| Score | Category | Action |
|---|---|---|
| 0–5 | Normal / Mild Malnutrition | Routine monitoring; reassess each clinic visit |
| 6–10 | Moderate Malnutrition | Dietary intervention; optimize dialysis adequacy; consider ONS |
| 11–20 | Moderately Severe Malnutrition | Prompt dietitian referral; ONS/IDPN; evaluate for reversible causes |
| 21–30 | Severe Malnutrition | Urgent multidisciplinary intervention; enteral/parenteral support; address inflammation |
SGA Global Rating
| Rating | Category | Action |
|---|---|---|
| A | Well Nourished | No intervention; re-assess at next clinic visit |
| B | Mildly / Moderately Malnourished | Dietary counseling; optimize protein and energy intake; re-assess in 4–6 weeks |
| C | Severely Malnourished | Urgent dietitian referral; ONS or IDPN; enteral nutrition if needed; address disease burden |
MIS Item Weights
| Item | Domain | Score (each item 0–3) |
|---|---|---|
| 1 | Dry weight change (3–6 months) | 0 = no change/gain; 1 = <0.5 kg; 2 = 0.5–1 kg; 3 = >1 kg loss |
| 2 | Dietary intake | 0 = normal; 1 = suboptimal solids; 2 = full liquid; 3 = very poor/starvation |
| 3 | GI symptoms (past 2 weeks) | 0 = none; 1 = occasional; 2 = frequent N/V; 3 = diarrhea/severe/anorexia |
| 4 | Functional capacity | 0 = normal; 1 = occasional fatigue; 2 = ADL difficulty; 3 = bedbound |
| 5 | Comorbidities / dialysis vintage | 0 = <1 yr HD, no comorbidities; 1 = mild; 2 = moderate; 3 = severe or ≥4 yr HD |
| 6 | Subcutaneous fat loss | 0 = normal; 1 = mild; 2 = moderate; 3 = severe |
| 7 | Muscle wasting signs | 0 = normal; 1 = mild; 2 = moderate; 3 = severe |
| 8 | BMI (kg/m²) | 0 = ≥20; 1 = 18–19.9; 2 = 16–17.9; 3 = <16 |
| 9 | Serum albumin (g/dL) | 0 = ≥4.0; 1 = 3.5–3.9; 2 = 3.0–3.4; 3 = <3.0 |
| 10 | TIBC (mg/dL) | 0 = ≥250; 1 = 200–249; 2 = 150–199; 3 = <150 |
Evidence & References
Protein-energy wasting (PEW) is a distinct syndrome defined by the International Society of Renal Nutrition and Metabolism (ISRNM) as depletion of body protein and energy stores in kidney disease. PEW is present in 28–54% of non-dialysis CKD patients and rises to 60–75% of maintenance hemodialysis patients. Validated nutritional screening instruments are essential because clinical signs of PEW may not be apparent until advanced depletion has occurred.
The Malnutrition-Inflammation Score (MIS) was developed by Kalantar-Zadeh and colleagues specifically for maintenance hemodialysis patients. In the validation cohort of 378 hemodialysis patients followed over 24 months, each 1-point increase in MIS was associated with a 6% rise in mortality risk (hazard ratio 1.06, 95% CI 1.03–1.09). MIS correlated strongly with serum markers of inflammation (CRP, IL-6) and with composite outcomes of hospitalization and death, outperforming serum albumin alone as a prognostic indicator.
The Subjective Global Assessment (SGA) was originally developed by Detsky and colleagues for surgical patients and validated by Steiber and colleagues in CKD. SGA is endorsed by KDOQI 2020 Nutrition Guideline as a standard nutritional assessment tool for kidney patients. In dialysis populations, SGA rating B or C is associated with 2- to 3-fold higher mortality and increased hospitalization compared with SGA-A. CKD SGA (modified for renal patients) includes an edema/fluid assessment component and is preferred over the general SGA in dialysis settings.
The SNAQ (Short Nutritional Assessment Questionnaire) was validated by Kruizenga and colleagues in 297 hospitalized general medical patients (sensitivity 79%, specificity 83% for malnutrition by SGA). Although not validated specifically in a renal cohort, SNAQ is widely used as a rapid first-line screening tool in hospital and dialysis units due to its simplicity and three-question format. A positive SNAQ (score ≥2) should prompt a full MIS or SGA assessment.
Key references:
- Kalantar-Zadeh K, Kopple JD, Block G, Humphreys MH. A malnutrition-inflammation score is correlated with morbidity and mortality in maintenance hemodialysis patients. Am J Kidney Dis. 2001;38(6):1251–1263.
- Detsky AS, McLaughlin JR, Baker JP, et al. What is subjective global assessment of nutritional status? JPEN J Parenter Enteral Nutr. 1987;11(1):8–13.
- Steiber AL, Kalantar-Zadeh K, Secker D, et al. Subjective Global Assessment in chronic kidney disease: a review. J Ren Nutr. 2004;14(4):191–200.
- Kruizenga HM, Seidell JC, de Vet HC, Wierdsma NJ, van Bokhorst-de van der Schueren MA. Development and validation of a hospital screening tool for malnutrition: the short nutritional assessment questionnaire (SNAQ). Clin Nutr. 2005;24(1):75–82.
- Fouque D, Kalantar-Zadeh K, Kopple J, et al. A proposed nomenclature and diagnostic criteria for protein-energy wasting in acute and chronic kidney disease. Kidney Int. 2008;73(4):391–398. (ISRNM PEW definition)
- KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. Am J Kidney Dis. 2020;76(3 Suppl 1):S1–S107.
