When a person experiences difficulty swallowing (dysphagia), it can severely impact nutritional status, hydration, and overall quality of life. This impairment often results from neurological events like stroke, or conditions such as Parkinson’s disease or head and neck cancer. Because swallowing function can range from a minor issue to a complete inability to eat or drink safely, healthcare providers require a standardized method to measure the severity of the problem. The Functional Oral Intake Scale (FOIS) provides a tool for objective measurement and communication.
Defining the Functional Oral Intake Scale
The Functional Oral Intake Scale (FOIS) is a validated, 8-point metric designed to classify a patient’s practical ability to consume food and liquids by mouth. Developed primarily by Speech-Language Pathologists (SLPs), the scale ranges from Level 0 to Level 7 and assesses the functional capacity for oral nutrition. The FOIS is not intended to measure the physiological mechanics of the swallow itself but rather the patient’s overall functional status in eating and drinking. Its primary goal is to determine the safety and independence of a patient’s intake, regardless of the specific texture modifications required. The resulting score provides a snapshot of the individual’s dependency on tube feeding and the complexity of their required oral diet.
Decoding the Eight Levels of Oral Intake
The FOIS uses eight levels to describe functional swallowing ability, with lower scores indicating greater dependency on non-oral feeding methods. A patient scoring Level 0 is classified as “Nothing by Mouth” (NPO), meaning all nutritional and hydration needs must be met through alternative routes, such as a feeding tube. Levels 1 through 3 describe states of tube dependency where the feeding tube remains the primary source of nutrition. A Level 1 patient is entirely tube-dependent with no oral intake, while Level 2 signifies tube dependency but with minimal, inconsistent attempts at oral consumption.
At Level 3, the patient is still tube-dependent but demonstrates consistent, regular oral intake, though not enough to meet full nutritional needs. The transition to total oral intake begins at Level 4, meaning the patient no longer requires a feeding tube but can only safely consume a diet of a single consistency (e.g., pureed or liquid). This score reflects a significant step toward functional independence, even with texture restrictions.
At Level 5, the patient is on a total oral diet including multiple food consistencies, but these require special preparation or compensatory strategies for safe consumption. This might involve modifying foods to be soft or using specific swallowing maneuvers taught by an SLP. Level 6 is assigned when a patient consumes a total oral diet with multiple consistencies and no special preparation, but they must still avoid specific items known to pose a risk, such as thin liquids or crunchy foods. Level 7 represents the highest functional outcome, where the patient is on a total oral diet with no restrictions or compensatory strategies required.
Using FOIS for Treatment and Progress Tracking
The initial FOIS score serves as a baseline measurement, providing an objective starting point for setting realistic clinical goals in dysphagia rehabilitation. For patients scoring in the tube-dependent range (Levels 0-3), the immediate goal may be to progress to consistent oral intake (Level 3) or total oral intake (Level 4). The SLP uses the score to guide specific interventions, such as choosing appropriate swallowing exercises or determining necessary diet modifications.
As therapy progresses, the FOIS is repeated to objectively track functional change over time, acting as a reliable measure of treatment efficacy. An increase in the FOIS score, for example, from Level 4 to Level 6, quantifies treatment success and justifies the next steps in the care plan. This systematic tracking allows the healthcare team to confirm that interventions are working, or to adjust the approach if the score remains stagnant or declines.
The scale provides a clear, standardized language that facilitates communication among all members of the interdisciplinary team, including physicians, nurses, dietitians, and family members. A shared understanding of the patient’s score eliminates ambiguity regarding the required diet consistency and the need for supplemental nutrition. This consistency ensures the patient receives coordinated, appropriate care that supports progression toward the safest and least restrictive diet possible.