1.1 Validated Geriatric Screening Tools

CSG Examination and Study Roadmap

OpenExamPrep provides this independent study guide for the Commission on Dietetic Registration’s Board Certified Specialist in Gerontological Nutrition (CSG) examination. CDR’s current 2026–2027 handbook specifies 150 multiple-choice items: 125 scored and 25 indistinguishable pretest items. Testing time is three hours; the appointment also includes a twenty-minute tutorial. The published fee is $350, and testing is offered year-round at Pearson centers after eligibility approval.

Candidates need current RD/RDN status held at least two years by examination day and 2,000 documented specialty practice hours within five years before application. Permitted substitutions can cover up to 800 hours. CDR uses an Angoff-derived, equated passing standard and does not publish one fixed percentage-correct requirement. After failure, reauthorization is required and the normal waiting period is sixty days; the handbook describes eligibility-window and limited waiver rules.

Assessment occupies Chapters 1–4, interventions Chapters 5–8, and foodservice/safety Chapters 9–10. Study application as well as definitions: evaluate evidence, diagnose nutrition problems, develop and modify plans, educate, coordinate, monitor, document, and improve systems. The 31 content topics and 15 secondary tasks in CDR’s outline guide these priorities.

Clinical vignettes and numerical outcomes throughout this guide are constructed teaching examples, not reported patient cases or guaranteed treatment effects.

Use CSG practice questions to identify gaps, then revisit the relevant teaching. Practice percentages are learning feedback, not an official score conversion.

Sources checked October 13, 2026: CDR handbook, CSG outline, and CDR fee page.

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Validated Geriatric Nutrition Screening Tools

Nutrition screening in gerontological practice is the essential first line of defense against undetected protein-energy malnutrition, micronutrient deficits, and functional decline. In older adults, malnutrition is rarely an isolated physiological event; it represents a complex geriatric syndrome driven by chronic disease catabolism, polypharmacy, dentition failure, social isolation, and sensory loss. Clinical screening must be distinguished from comprehensive nutrition assessment. Screening is a rapid, non-invasive triage process performed by any trained healthcare team member to identify individuals who are malnourished or at nutritional risk. In contrast, assessment is an in-depth diagnostic evaluation usually led by a Registered Dietitian Nutritionist (RDN), drawing on interdisciplinary findings.

Clinical Timing and Assessment

Screen promptly on entry to care and repeat when intake, weight, illness, function, or living circumstances change. Local hospital policies commonly specify early admission screening. A universal 24- or 48-hour nutrition-screening mandate should not be applied to every setting. CMS requires a baseline nursing-facility care plan within 48 hours; this is distinct from completing a comprehensive assessment. An urgent swallowing or hydration problem needs immediate attention regardless of the routine assessment schedule.

Mini Nutritional Assessment - Short Form (MNA-SF)

The MNA-SF is a widely used instrument developed for older adults. Sensitivity and specificity depend on the version, population, and comparison standard; do not assign one performance estimate to all care settings. A positive screen prompts assessment rather than an automatic feeding-tube or appetite-stimulant order.

The Six Core Parameters and Calf Circumference Option

The MNA-SF condenses geriatric nutritional vulnerability into six distinct questions evaluating status over the preceding 3 months:

1. Food Intake Decline (Item A): Assesses reduced food intake over the past 3 months due to loss of appetite, digestive issues, or chewing/swallowing difficulties (0 = severe decrease, 1 = moderate decrease, 2 = no decrease).
2. Involuntary Weight Loss (Item B): Evaluates unintentional weight loss over the past 3 months (0 = weight loss $> 3\text{ kg}$ [6.6 lbs], 1 = does not know, 2 = weight loss between 1 and 3 kg [2.2 to 6.6 lbs], 3 = no weight loss).
3. Mobility (Item C): Assesses ambulatory capacity (0 = bed or chair bound, 1 = able to get out of bed/chair but does not go out, 2 = goes out).
4. Acute Disease or Psychological Stress (Item D): Determines presence of acute illness or severe stress in the past 3 months (0 = yes, 2 = no).
5. Neuropsychological Problems (Item E): Evaluates cognitive and affective status (0 = severe dementia or depression, 1 = mild dementia, 2 = no psychological problems).
6. BMI or Calf Circumference (Item F): Evaluates somatic reserve via Item F1 (BMI $< 19.0\text{ kg/m}^2 = 0$, $19.0\text{ to } < 21.0 = 1$, $21.0\text{ to } < 23.0 = 2$, $\ge 23.0 = 3$).

Crucially, when acute illness, contractures, or immobility prevent obtaining standing height and weight, Item F2 substitutes calf circumference (CC):

• Calf Circumference $< 31.0\text{ cm} = 0\text{ points}$
• Calf Circumference $\ge 31.0\text{ cm} = 3\text{ points}$

Scoring Tiers and Clinical Action Pathways

The maximum MNA-SF score is 14 points, stratifying patients into three clinical tiers:

The Full Mini Nutritional Assessment (Full MNA)

When a screen indicates risk, complete a comprehensive assessment. Clinicians may use the Full MNA (18 items, maximum 30 points) according to its own form and instructions. Do not add twelve items to a calf-substituted MNA-SF score and assume that this is automatically a validated Full MNA total; verify the version and complete its required measurements. The additional items explore:

• Independent living arrangements and prescription medication burden ($> 3$ medications daily).
• Presence of skin ulcers or pressure injuries.
• Detailed protein intake (dairy, eggs, legumes, meat, poultry, fish), fluid intake, and fruit/vegetable intake.
• Feeding ability (unable without help, self-fed with difficulty, or self-fed without difficulty).
• Self-perceived health and nutritional status.
• Mid-arm circumference (MAC $< 21.0\text{ cm} = 0$, $21.0\text{ to } 22.0\text{ cm} = 0.5$, $> 22.0\text{ cm} = 1$) and calf circumference ($< 31.0\text{ cm} = 0$, $\ge 31.0\text{ cm} = 1$).

Full MNA scoring: 24 to 30 points indicates normal status; 17 to 23.5 points indicates risk of malnutrition; $< 17\text{ points}$ indicates protein-energy malnutrition.

Alternative Validated Screening Tools: MUST, MST, and NRS-2002

Specialists in gerontological nutrition must recognize alternative validated screening instruments:

• Malnutrition Universal Screening Tool (MUST): A 5-step tool developed by BAPEN evaluating BMI ($> 20 = 0$, $18.5\text{ to } 20 = 1$, $< 18.5 = 2$), unplanned weight loss in 3 to 6 months ($< 5\% = 0$, $5\%\text{ to } 10\% = 1$, $> 10\% = 2$), and acute disease causing no intake for more than five days, actual or expected ($+2\text{ points}$). Scores of 0 indicate low risk, 1 medium risk, and $\ge 2$ high risk.
• Malnutrition Screening Tool (MST): An ultra-rapid 2-question tool assessing recent unintentional weight loss amount/uncertainty (up to 4 points) and poor dietary intake due to decreased appetite (1 point). A score $\ge 2$ indicates nutritional risk requiring RDN referral.
• Nutritional Risk Screening 2002 (NRS-2002): Combines nutritional impairment (0 to 3) and illness severity (0 to 3), adding 1 point for age $\ge 70\text{ years}$. A score $\ge 3$ indicates nutritional risk.

Comparison of Validated Screening Instruments

Illustrative Clinical Case

The following is a constructed teaching example; its course and outcomes are not a prediction for every patient.

An 84-year-old female with vascular dementia is admitted to a skilled nursing facility following a hip fracture repair. Screening reveals: moderate food intake decline over 2 months (Item A = 1), 2 kg unintentional weight loss (Item B = 2), chair-bound mobility (Item C = 0), acute surgical trauma within 3 months (Item D = 0), mild dementia (Item E = 1), and calf circumference of 29.5 cm due to inability to stand (Item F2 = 0).

Score: $1 + 2 + 0 + 0 + 1 + 0 = 4\text{ points}$ (malnourished). The RDN immediately initiates comprehensive assessment, target protein intake of 1.2 to 1.5 g/kg, fortified meals, and speech pathology evaluation.

CSG Board Exam Tips & Common Traps

• Screening vs. Assessment: Screening identifies risk rapidly and can be conducted by any clinician; assessment is diagnostic, comprehensive, and performed by an RDN.
• Calf Circumference Cutoff: On the MNA-SF, the calf circumference threshold is strictly 31 cm ($< 31\text{ cm} = 0$, $\ge 31\text{ cm} = 3$). Do not confuse this with Mid-Arm Circumference ($< 21\text{ cm}$).
• Item D Binary Scoring: Item D on acute stress/illness scores either 0 (stress present) or 2 (stress absent); there is no 1-point option.
• NRS-2002 Age Rule: NRS-2002 adds 1 point for age $\ge 70\text{ years}$ to capture reduced physiological reserve.

Primary source check

MNA official forms and user guide, checked October 13, 2026.

BAPEN MUST guidance, checked October 13, 2026.