Myalgic Encephalomyelitis (ME) is a severe and disabling chronic multi-systemic disease.
ME affects men, women and children of all ages, ethnicities, and socioeconomic backgrounds. It is estimated that 75 - 80% of people with the condition are female, and that around 25% of people with ME experience severe/very severe/profound/ symptoms.
In the International Consensus Criteria 2011, Carruthers et al defined a severity scale for ME of mild (at least a 50% reduction in pre-illness activity level), moderate (mostly housebound), severe (mostly bedridden), and very severe (completely bedridden and requiring assistance with basic functions).
Studies of disability in people with ME have estimated that 75% are housebound most of the time, 50% are too ill and disabled to work, and 25% are confined to bed most of the time.
Full recovery is rare (estimated at less than 5%), although some with ME experience remission of symptoms for extended periods, followed by relapse.
For example, patients mildly impaired by ME may be able, with careful planning and activity management, to keep a job or continue their education, participate in social and family activities, and attend to daily life. Those patients who are moderately impaired might, for example, have trouble maintaining a regular work schedule or standing and sitting for prolonged periods. Patients who are severely or very severely affected by ME include those who are completely wheelchair-dependent and confined to bed for months or even years.
As said already the different severities of Myalgic Encephalomyelitis (ME) are:
These are general categories which really have ranges within themselves i.e. Mild has its own range, as does Moderate and so on.
Those in the severe categories of ME are so extremely ill there is no benefit to pacing, a technique that may help those at the more mild/moderate end of the scale. Just having someone walk into the bedroom of someone with very severe ME could result in relapse/crisis and severe symptoms.
Grading patient’s symptom and disease severity for comparison and management decision-making is necessary.
Symptom and disease severity is discussed in the clinical application section of the International Consensus Criteria (ICC): “For a diagnosis of ME, symptom severity must result in a significant reduction in a patient’s premorbid activity level. Mild: approximately 50% reduction in activity, moderate: mostly housebound, severe: mostly bedbound, and very severe: bedbound and dependent on help for physical functions”.
One of the ICC’s considerations was to classify patient disease severity to increase patient group homogeneity in research.
History taking and clinical severity grading might be challenging because of its dependence on the interpretation of symptomatology by the patient. Adding more objective measures to confirm symptom severity and clinical grading may be helpful.
Severity grading is rarely reported in ME research and limited information is available on objective measures linked to disease severity. The proposed grading of the ICC, which mainly focusses on the ability/inability to perform physical activities is not adequate enough to detail a patient's illness and symptom severity, so we suggest that ME patients use a few tools such as the De Paul Symptoms/Severities Questionnaire along with the Bells Disability & Severity Scale, see more about those below.
Symptom and Severity Questionnaire
The DePaul Symptom Questionnaire (DSQ-2) is a self-report assessment created by Leonard Jason at DePaul University, Chicago, Illinois, US. With 54 questions in total, the DSQ Symptom Questionnaire assesses key symptoms of ME such as post-exertional neuro-immune exhaustion or PENE (referred to as PEM in the questionnaire), sleep, pain, neurological/cognitive impairments and autonomic, neuroendocrine and immune symptoms.
At each item, participants have to rate the frequency and severity of the symptom on a scale from 0 to 4. You can put a score for how frequently you have each symptom and how severe it is.
The questionnaire is based on research so useful to print out to complete and shown to your GP/Consultant/other.
As much as anything the questionnaire can teach your GP what ME is, and highlights your severities across different symptoms.
This is the link to the DSQ-2 symptom questionnaire.
Bell's Disability Scale
A good scale that could be used along with the categories Mild, Moderate, Severe, Very Severe, Profound, to determine near exact range, is the Bell's Disability Scale. Different people suffer in different ways but the scale gives an idea of the level of disability. It may be the case that it doesn't reflect your severity exactly but it is a useful tool for some patients to get across the extent of their ME severity to medics & others. See image in comments.
The Bell's Disability Scale can be used by both Patient and Doctor to track and monitor progress/relapses of ME over time.
Tick which descriptor best describes you.
Bells Disability Scale
100 No symptoms at rest; no symptoms with exercise; normal overall activity level; able to work fulltime without difficulty.
90 No symptoms at rest; mild symptoms with activity; normal overall activity level; able to work full-time without difficulty.
80 Mild symptoms at rest; symptoms worsened by exertion; minimal activity restriction noted for activities requiring exertion only; able to work full-time with difficulty in jobs requiring exertion.
70 Mild symptoms at rest; some daily activity limitation clearly noted; overall functioning close to 90% of expected except for activities requiring exertion; able to work full-time with difficulty.
60 Mild to moderate symptoms at rest; daily activity limitation clearly noted; overall functioning 70% - 90%; unable to work full-time in jobs requiring physical labour, but able to work full-time in light activities if hours flexible.
50 Moderate symptoms at rest; moderate to severe symptoms with exercise or activity; overall activity level reduced to 70% of expected; unable to perform strenuous duties, but able to perform light duty or desk work 4-5 hours a day, but requires rest periods.
40 Moderate symptoms at rest; moderate to severe symptoms with exercise or activity; overall level reduced to 50% - 70% of expected; not confined to house; unable to perform strenuous duties; able to perform light duty or desk work 3-4 hours a day but requires rest periods.
30 Moderate to severe symptoms at rest; severe symptoms with any exercise; overall activity level reduced to 50% of expected; usually confined to house; unable to perform strenuous tasks; able to perform desk work 2-3 hours a day, but requires rest periods.
20 Moderate to severe symptoms at rest; severe symptoms with any exercise; overall activity level reduced to 30% - 50% of expected; unable to leave house except rarely; confined to bed most of day; unable to concentrate for more than 1 hour a day.
10 Severe symptoms at rest; bedridden the majority of the time; no travel outside of the house; marked cognitive symptoms preventing concentration.
0 Severe symptoms on a continuous basis; bedridden constantly; unable to care for self
Link to printable Bell's Scale here
Very Severe ME
The films from the Dialogues for a Neglected Illness series by Natalie Bolton and Josg Riggs includes a film about Severe & Very Severe ME
To get across what the more severe end of the ME severity scale looks like please watch this video by Greg Crowhurst which features his wife Linda Crowhurst who has had ME for more than two decades and suffers from very severe ME with very severe and profound symptoms. 'Wasteland' visually documents Linda's very severe ME here.
The main finding of a 2020 study entitled Validation of the Severity of Myalgic Encephalomyelitis by Other Measures than History: Activity Bracelet, Cardiopulmonary Exercise Testing and a Validated Activity Questionnaire: SF-36 is that the physical function subscale of the SF- 36 questionnaire, and objective measures such as the number of steps per day on an activity meter and measures of percent oxygen consumption at ventilatory threshold and at peak exercise, showed a clear distinction between mild, moderate and severe ME patients. The physical activity subscale of the SF-36 (a structured, self-report health status questionnaire that the patient can generally complete with little or no intervention from an interviewer), the number of steps per day, and oxygen consumption data all decreased significantly with increasing ICC severity.
The study concluded that disease severity grading as suggested by Carruthers in the ICC on ME is validated by using questionnaires and more objective measures as the number of steps or cardiopulmonary exercise test parameters. It showed a well-defined difference between ICC severity categories and physical activity on the SF-36 questionnaire, as well as in the number of steps per day and the percentage predicted oxygen consumption at the ventilatory threshold and peak exercise.
The study researchers reported that with this information, the history of the patients reported outcomes on ME can be confirmed and be more comprehensible for the patient and their caretakers, treating physicians and others. Moreover, it increases patient group homogeneity in ME research.