The Modified Fatigue Impact Scale (MFIS) is a self-report questionnaire designed to measure the effects of fatigue on a person’s life. It originated from interviews with multiple sclerosis patients who described how fatigue influenced their daily activities. The primary purpose of the tool is to provide a structured way to quantify the impact of this symptom, allowing healthcare providers to translate the subjective feeling of being tired into a concrete measurement.
Domains of Fatigue Assessed by the MFIS
The MFIS evaluates how fatigue affects three specific areas of a person’s life: the physical, cognitive, and psychosocial domains. This multi-faceted approach recognizes that fatigue is more than just physical tiredness. By separating these components, the scale provides a detailed picture of the challenges an individual faces, showing whether fatigue predominantly affects a person’s body, mind, or social interactions.
The physical domain assesses the impact of fatigue on activities requiring bodily effort. Questions in this subscale inquire about feelings of heavy limbs, reduced physical endurance, and the need for more frequent rest. It aims to capture how fatigue limits a person’s ability to perform tasks such as walking, exercising, or completing household chores.
The cognitive subscale focuses on how fatigue affects mental processes. This includes its influence on concentration, memory, and the ability to think clearly and organize thoughts. Questions might ask about difficulty paying attention for long periods or struggling to find the right words. These items help measure the “brain fog” that can interfere with work, planning, and problem-solving.
The psychosocial domain examines the effect of fatigue on a person’s engagement with others and their ability to fulfill social and work-related roles. This part of the scale addresses how fatigue may cause an individual to withdraw from social activities or struggle to meet responsibilities at work or home. It highlights the isolating nature of fatigue and its capacity to disrupt personal and professional relationships.
Test Format and Scoring Method
The standard MFIS is a 21-item questionnaire that patients complete on their own, which takes about five to ten minutes. For individuals who have difficulty with reading or writing, the questionnaire can be administered as an interview. There is also a shortened 5-item version available for situations where time is limited.
Each of the 21 statements describes a way fatigue might affect a person’s life. Respondents rate how frequently they have experienced each item over the preceding four weeks. The rating is done on a 5-point scale: 0 for “never,” 1 for “rarely,” 2 for “sometimes,” 3 for “often,” and 4 for “almost always.” This structure allows for a nuanced response.
The total MFIS score is calculated by summing the responses from all 21 questions, with a possible range from 0 to 84. Separate scores can also be calculated for each of the three subscales. The physical subscale score can range up to 36 points, the cognitive up to 40, and the psychosocial up to 8.
Understanding Your MFIS Score
A higher score on the MFIS indicates that fatigue has a more significant impact on an individual’s daily life. The score is not a diagnostic tool for a specific condition but rather a measurement of the perceived severity of the fatigue itself. It provides a snapshot of the person’s experience during the previous four-week period.
The value of the MFIS score is often seen when tracking changes over time. By administering the scale at different points, clinicians can monitor whether a person’s fatigue is improving or worsening. This is useful for assessing the effectiveness of treatments or interventions aimed at managing fatigue. A decrease in the score suggests that interventions are having a positive effect.
The subscale scores offer additional insight beyond the total score. For instance, a high score on the cognitive subscale might prompt a discussion about strategies to manage mental fogginess, while a high physical score could lead to recommendations for energy conservation. By examining the domain scores, healthcare providers and patients can create a more targeted management plan.
Application in Medical Settings
The MFIS is most widely used for assessing fatigue in individuals with multiple sclerosis (MS). Fatigue is a common symptom of MS, and the MFIS provides a structured method to track its impact. Because fatigue is an invisible symptom, a quantitative measure helps to legitimize the patient’s experience and guide management strategies.
While its origins are tied to MS, the MFIS has expanded to other medical conditions where fatigue is a prominent symptom. It is used for patients recovering from traumatic brain injury (TBI) and stroke. Researchers also use the scale to understand the impact of fatigue in systemic lupus erythematosus and chronic fatigue syndrome.
In clinical settings, the MFIS scores help doctors gauge the severity of fatigue and can inform recommendations for therapies. For example, high scores on the psychosocial subscale might lead to a referral for cognitive behavioral therapy. The scale is also used in clinical trials to measure the effectiveness of new treatments.