CalcPT

Dysphagia

Functional Oral Intake Scale (FOIS) calculator

Ordinal 1-7 clinician rating of current oral intake, from nothing by mouth (level 1) to unrestricted diet (level 7).

Current functional oral intake level

FOIS level

Select a level

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Pick the level that best describes the patient's current oral intake status.

About the FOIS

The Functional Oral Intake Scale was developed by Michael Crary and colleagues at the University of Florida and published in 2005 in the Archives of Physical Medicine and Rehabilitation. It was designed as a brief, ordinal, clinician- rated description of a patient’s current oral intake — specifically, whether they are taking nutrition by mouth, and if so, how restricted that intake is. The scale runs from level 1 (nothing by mouth) to level 7 (total oral intake with no restrictions). Levels 2 and 3 describe tube-dependent patients with some oral intake; levels 4 through 6 describe patients on full oral diets with increasing freedom; level 7 is unrestricted eating and drinking.

How to use it

Rate the patient based on their current diet at the time of assessment. FOIS is a descriptive tool — it does not encode swallowing safety directly, and a patient can be at a high FOIS level while still having a physiological impairment. That is by design: FOIS is about what the patient is eating, not about whether they ought to be eating that way. When you need a combined severity picture that incorporates supervision, modifications, and nutrition route, the Dysphagia Outcome and Severity Scale (DOSS) is a complement.

Clinical context

FOIS has become one of the most widely used outcome measures in dysphagia rehabilitation, particularly in stroke and head-and-neck cancer populations, because a one-level change is easy to interpret for patients and families and because its brevity makes it practical for routine documentation. It is used both as a descriptor of current status and as a longitudinal tracker of change over an episode of care. Because the scale is ordinal, averaging level values across sessions is not meaningful; report levels as a series, and describe change in words.

Limitations

FOIS captures only oral intake. It does not describe airway invasion, the presence of aspiration, residue, or the physiological impairment driving the observed diet level. For those dimensions, pair FOIS with an instrumental assessment and a scale such as the Penetration-Aspiration Scale. It also does not describe patient preferences, quality of life, or symptom burden — where those matter, consider the EAT-10 as a complementary patient-reported measure.

Primary source: Crary MA, Mann GDC, Groher ME. Initial psychometric assessment of a functional oral intake scale for dysphagia in stroke patients. Archives of Physical Medicine and Rehabilitation. 2005;86(8):1516-1520.

Frequently asked questions

What does the FOIS measure?
The Functional Oral Intake Scale is a clinician rating of how a patient is currently eating and drinking. Level 1 is nothing by mouth; level 7 is total oral intake with no restrictions. It captures functional status, not airway invasion or safety per se.
Who developed FOIS and in what population?
Crary, Mann, and Groher developed FOIS and published initial psychometric data in stroke patients in 2005 in the Archives of Physical Medicine and Rehabilitation. It has since been adopted across neurogenic and non-neurogenic dysphagia populations.
How is FOIS different from DOSS?
FOIS describes oral intake (what the patient is eating and how). DOSS is a broader severity rating that combines diet level, independence, supervision needs, and nutrition route. DOSS tends to incorporate more of the clinical picture; FOIS is a cleaner description of diet alone.
Can I average FOIS scores over time?
No. FOIS is ordinal — the "distance" between levels is not equal — so averaging is not meaningful. Report level-over-time as a series and describe change qualitatively.
What is a clinically meaningful change?
A one-level change is generally considered meaningful and is often used as an outcome endpoint in dysphagia rehabilitation studies. Judge in context of the baseline level and the specific clinical picture.

See more dysphagia tools on the Dysphagia Suite hub.