Questionnaires and tools to assess ME/CFS symptoms or severity

Many different questionnaires, symptom scales and self-report tools can be used to measure the the severity or impact of particular ME/CFS symptoms, of ME/CFS, and the level of disability in ME/CFS patients.

Many questionnaires and symptom scales used for ME/CFS patients can also be used for patients with fibromyalgia or other chronic illnesses, for example those that assess pain, fatigue, overall disability or physical health, but some are designed to assess the unique combination of symptoms found in myalgic encephalomyelitis or chronic fatigue syndrome for example post-exertional malaise.

ME/CFS self-report tools
Commonly used self-report tools and questionnaires include:
 * Bell CFIDS disability scale
 * Chalder fatigue scale
 * DePaul Pediatric Health Screening Questionnaire - for children and adolescents
 * DePaul Post-Exertional Malaise Questionnaire
 * DePaul Symptom Questionnaire

Less commonly used

 * AYME Functional Ability Scale - for children and adolescents
 * Bansal Score Chart for ME/CFS
 * Campbell CFS/Fibromyalgia Rating Scale
 * CDC 2005 Symptom Inventory for CFS
 * HFME 3 Part ME Ability and Severity Scale
 * ME Association ME/CFS Disability Rating Scale
 * Phoenix Rising Energy Index Scale
 * Shepherd ME/CFS Disability Scale

General self-report tools
General self-report tools and questionnaires used in ME/CFS patients include:
 * Borg CR-10
 * Borg Rating of Perceived Exertion Scale (RPE scale)
 * Energy Index Point Score
 * Fatigue Severity Scale
 * Fennell Phase Inventory
 * Checklist Individual Strength
 * Karnofsky Performance Scale
 * Multidimensional Fatigue Inventory-20
 * PROMIS F-SF
 * Short Form 36-Item Health Survey
 * Visual-analogue scale
 * Widespread Pain Index
 * International Symptom Scale (ICC)
 * Functional Capacity Scale Definition
 * Moss Ability Scale (original)
 * Total Daily Symptom Score (TDSS)

Suitability of scales for severe ME
Some scales have a ceiling effect or floor effect, where a large range of variation in ME/CFS cannot be distinguished between, leading to a cluster or very high or very low scores.

Subjective and objective assessments
Symptom scales are usually subjective (based on the person's opinion) and so can be at risk of response bias. Symptom scales are a common form of Patient Rated Outcome Measure (PROM) used in clinical trials.

Symptom scales or other forms of self-assessment should be used together with objective measures, e.g., school/work attendance record, distance walked in 6 mins, cardiopulmonary exercise test (CPET), pain medication consumption, or VO2 max.

Notable studies

 * 2000, Fatigue rating scales: an empirical comparison - (Abstract)
 * 2011, Fatigue Scales and Chronic Fatigue Syndrome: Issues of Sensitivity and Specificity - (Full text)
 * 2014, The delayed fatigue effect in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) - (Full text)
 * Significant differences were found between pre- and post-test measures in three MFI sub-scales of fatigue (general, mental, and physical) and on the depression scale of the HADS. However, there were no significant changes in motivation, activity level, or self-reported anxiety scores.


 * 2016, Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome (Full text)
 * 2016, The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome - (Full Text)
 * 2018, Operationalizing Substantial Reduction in Functioning Among Young Adults with Chronic Fatigue Syndrome - (Full text)
 * The four top performing subscales and their associated cutoffs were determined: Physical Functioning ≤ 80, General Health ≤ 47, Role Physical ≤ 25, and Social Functioning ≤ 50. Used in combination, these four cutoff scores were shown to reliably discriminate between the patients and controls in our sample of young adults


 * 2020, Validation of the Severity of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome by Other Measures than History: Activity Bracelet, Cardiopulmonary Exercise Testing and a Validated Activity Questionnaire: SF-36 - (Full text)
 * Symptoms limiting the test were exhaustion in all patients, muscle pain in 80% as one of the symptoms at the end of the test, and dizziness in 8%.