Fellowship: Stanford University Child Psychology Postdoctoral Fellowship (2021) CA
Internship: Stanford University Psychology (2020) CA
Doctor of Philosophy, DePaul University, Clinical Psychology (2020)
Master of Arts, DePaul University, Clinical Psychology (2016)
- A Framework for Navigating Requests for Nondisclosure in Pediatric Palliative Care CLINICAL PRACTICE IN PEDIATRIC PSYCHOLOGY 2021; 9 (3): 296-307
- Patient-Reported Experiences With Median Arcuate Ligament Syndrome: Resilience and Resources Required CLINICAL PRACTICE IN PEDIATRIC PSYCHOLOGY 2021
Risks for Developing ME/CFS in College Students Following Infectious Mononucleosis: A Prospective Cohort Study.
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) involves severe fatigue, unrefreshing sleep, and cognitive impairment, leading to functional difficulties; prior studies have not evaluated risk factors with behavioral and immune data collected prior to developing ME/CFS.. Up to 5% of university students develop infectious mononucleosis (IM) annually, and 9-12% meet criteria for ME/CFS six months later. We sought to determine predictors of ME/CFS.METHODS: We enrolled college students at the start of the school year (Time 1), identified those who developed IM (Time 2) and followed them for 6 months (Time 3), identifying three groups: those who developed ME/CFS, those who developed severe ME/CFS (meeting >1 set of criteria) and those who were asymptomatic. We conducted 8 behavioral and psychological surveys and analyzed cytokines at three time points.RESULTS: 238 of the 4501 students (5.3%) developed IM; 6 months later, 55 of the 238 (23%) met criteria for ME/CFS and 157 (66%) were asymptomatic. 67 of the 157 asymptomatic students served as controls. Students with severe-ME/CFS were compared to students who were asymptomatic at three time points. The former group was not different from the latter group at Time 1 (prior to developing IM) in stress, coping, anxiety or depression, but were different in several behavioral measures and had significantly lower levels of IL-6 and IL-13. At Time 2 (when they developed IM), the two ME/CFS groups tended to have more autonomic complaints and behavioral symptoms while the severe- ME/CFS group had higher levels of IL-12 and lower levels of IL-13 than the recovered group.CONCLUSION: At baseline, those who developed ME/CFS had more physical symptoms and immune irregularities, but not more psychological symptoms, than those who recovered.
View details for DOI 10.1093/cid/ciaa1886
View details for PubMedID 33367564
Activity measurement in pediatric chronic fatigue syndrome.
OBJECTIVES: Individuals with myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) experience debilitating symptoms, including post-exertional malaise, an intensification of symptoms after physical or cognitive exertion. Previous studies found differences in the activity levels and patterns of activity among individuals with ME and CFS, compared to healthy controls; however, limited research exists on the activity levels of pediatric patients. The objective of this study was to examine differences in activity between healthy children and youth with ME and CFS.METHODS: The present study examines the objective (i.e., ActiGraphy) and self-reported levels of activity among children (ages 5 to 17) enrolled in a community-based study of pediatric CFS.RESULTS: Children with ME and CFS evidenced lower activity levels than healthy control children. Moreover, participants with ME and CFS evidenced increased nighttime activity and delayed initiation of daytime activity. Participants' self-reported activity data significantly correlated with their ActiGraph data, suggesting that children with ME and CFS are able to accurately describe their activity level.DISCUSSION: This study highlights differences in activity level and diurnal/nocturnal activity patterns between healthy children and those with ME and CFS. These differences should be considered in identifying appropriate supports and accommodations for children with ME and CFS.
View details for DOI 10.1177/1742395320949613
View details for PubMedID 32806955
The Prevalence of Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in a Community‑Based Sample.
Child & youth care forum
2020; 49 (4): 563-579
Most pediatric prevalence studies of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) have been based upon data from tertiary care centers, a process known for systematic biases such as excluding youth of lower socioeconomic status and those less likely to have access to health care. In addition, most pediatric ME/CFS epidemiologic studies have not included a thorough medical and psychiatric examination. The purpose of this study was to determine the prevalence of pediatric ME/CFS from an ethnically and sociodemographically diverse community-based random sample.A sample of 10,119 youth aged 5-17 from 5622 households in the Chicagoland area were screened. Following evaluations, a team of physicians made final diagnoses. Youth were given a diagnosis of ME/CFS if they met criteria for three selected case definitions. A probabilistic, multi-stage formula was used for final prevalence calculations.The prevalence of pediatric ME/CFS was 0.75%, with a higher percentage being African American and Latinx than Caucasian. Of the youth diagnosed with ME/CFS, less than 5% had been previously diagnosed with the illness.Many youth with the illness have not been previously diagnosed with ME/CFS. These findings point to the need for better ways to identify and diagnose youth with this illness.
View details for DOI 10.1007/s10566-019-09543-3
View details for PubMedID 34113066
View details for PubMedCentralID PMC8186295
- The Prevalence of Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in a Community-Based Sample CHILD & YOUTH CARE FORUM 2020; 49 (4): 563–79
The Development of a Short Form of the DePaul Symptom Questionnaire
2019; 64 (4): 453–62
The DePaul Symptom Questionnaire (DSQ) is a widely used instrument that assesses common symptoms of myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). The DSQ has strong psychometric properties; however, it consists of 99 items, and the energy limitations and cognitive difficulties experienced by individuals with ME and CFS may hinder their ability to easily complete the questionnaire.The current study examined symptom prevalence and discriminative ability to develop a short form of the DSQ (DSQ-SF).The resulting short form questionnaire consists of 14 items that were highly prevalent among individuals with ME and CFS. Additionally, the items demonstrated the ability to differentiate individuals with ME and CFS from adult controls and, to a lesser extent, individuals with multiple sclerosis.The DSQ-SF may serve as an effective, brief screening tool for symptoms of ME and CFS. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
View details for DOI 10.1037/rep0000285
View details for Web of Science ID 000491284200007
View details for PubMedID 31318234
View details for PubMedCentralID PMC6803042
- Rethinking the Standard of Care for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome JOURNAL OF GENERAL INTERNAL MEDICINE 2020; 35 (3): 906–9
Approaching recovery from myalgic encephalomyelitis and chronic fatigue syndrome: Challenges to consider in research and practice
JOURNAL OF HEALTH PSYCHOLOGY
2019; 24 (10): 1412–24
There are unique methodological challenges to studying and assessing recovery in myalgic encephalomyelitis and chronic fatigue syndrome. This study explored these challenges through interviewing 13 physicians who treat myalgic encephalomyelitis and chronic fatigue syndrome. Our deductive thematic analysis produced four themes to consider when approaching recovery: lifespan differences in the illness experience; the heterogeneity of myalgic encephalomyelitis and chronic fatigue syndrome-case definitions, etiological stance, and misdiagnosis; patient follow-up and selection bias; and assessment logistics. We discuss how researchers and clinicians can use these considerations when working with patients, drafting recovery criteria, and interpreting treatment outcomes.
View details for DOI 10.1177/1359105317742195
View details for Web of Science ID 000480262900010
View details for PubMedID 29182007
View details for PubMedCentralID PMC5930162
- Autonomic dysfunction in myalgic encephalomyelitis and chronic fatigue syndrome: comparing self-report and objective measures CLINICAL AUTONOMIC RESEARCH 2019; 29 (4): 475–77
Energy envelope maintenance among patients with myalgic encephalomyelitis and chronic fatigue syndrome: Implications of limited energy reserves
2019; 15 (1): 51–60
The Energy Envelope Theory of myalgic encephalomyelitis and chronic fatigue syndrome postulates that individuals with myalgic encephalomyelitis and chronic fatigue syndrome may experience some increase in functioning if their level of exertion consistently remains within the limits of their available energy. Findings of several studies support this theory; however, the current study is the first to explore how an individual's initial level of available energy may influence the relation between energy envelope maintenance and level of functioning.The functioning, activity, and symptomatology of six groups of individuals with myalgic encephalomyelitis and chronic fatigue syndrome were compared. Groups were created based upon level of available energy (higher or lower) and energy envelope adherence (underextended, within, overextended).Results indicate that, as expected, individuals with myalgic encephalomyelitis and chronic fatigue syndrome who had higher available energy also had better functioning than individuals with lower available energy; however, this relation was less pronounced for individuals who were overexerting themselves.These results are consistent with the Energy Envelope Theory, and they suggest that overexertion was particularly impactful for individuals with higher levels of available energy.
View details for DOI 10.1177/1742395317746470
View details for Web of Science ID 000458763400004
View details for PubMedID 29231037
View details for PubMedCentralID PMC5750135
Deconstructing post-exertional malaise: An exploratory factor analysis
JOURNAL OF HEALTH PSYCHOLOGY
2019; 24 (2): 188–98
Post-exertional malaise is a cardinal symptom of myalgic encephalomyelitis and chronic fatigue syndrome. There are two differing focuses when defining post-exertional malaise: a generalized, full-body fatigue and a muscle-specific fatigue. This study aimed to discern whether post-exertional malaise is a unified construct or whether it is composed of two smaller constructs, muscle fatigue and generalized fatigue. An exploratory factor analysis was conducted on several symptoms that assess post-exertional malaise. The results suggest that post-exertional malaise is composed of two empirically different experiences, one for generalized fatigue and one for muscle-specific fatigue.
View details for DOI 10.1177/1359105316664139
View details for Web of Science ID 000456745000004
View details for PubMedID 27557649
View details for PubMedCentralID PMC5325824
Defining and measuring recovery from myalgic encephalomyelitis and chronic fatigue syndrome: the physician perspective
DISABILITY AND REHABILITATION
2019; 41 (2): 158–65
To inform an operationalised definition of recovery from myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) for research and practice. Without a consensus on defining and measuring recovery, there will continue to be controversy amongst researchers, clinicians, and patients when interpreting treatment outcomes.This study explores physicians' views on recovery from ME and CFS. We conducted semi-structured interviews with 10 physician participants who are experts in the ME and CFS field. Our deductive thematic analysis, using a realist perspective, provided a framework for differentiating recovery and significant improvement.Physicians conceptualised recovery as complete symptom remission and a return to premorbid functioning (adjusted for with age), whereas they viewed significant improvement as a substantial reduction in symptoms with considerable functional gains, where patients may operate in daily life but still must cope or be treated.Our findings provide recommendations and approaches for measuring: daily functioning, symptomatology, quality of life, and physical functioning. Implications for rehabilitation Physicians viewed recovery as complete symptom remission and a return to premorbid functioning (adjusted for with age). Recovery from myalgic encephalomyelitis and chronic fatigue syndrome should be viewed as multidimensional, considering patients' daily life, psychosocial functioning, and overall physical functioning. These findings can improve practitioner-client interactions, as they provide recommendations for measuring recovery in research and practice.
View details for DOI 10.1080/09638288.2017.1383518
View details for Web of Science ID 000458323300005
View details for PubMedID 28982247
View details for PubMedCentralID PMC6123286
Differentiating Post-Polio Syndrome from Myalgic Encephalomyelitis and Chronic Fatigue Syndrome.
Fatigue : biomedicine, health & behavior
2019; 7 (4): 196–206
Overlapping and concomitant symptoms among similar chronic illnesses have created difficulties for diagnosis and further treatment. Three such chronically fatiguing illnesses, Post-polio syndrome (PPS), Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS) fall under this category.The aim of this study is to examine and distinguish between core symptoms found in these illnesses (i.e. muscle pain/weakness, fatigue or exhaustion, and autonomic symptoms) via three methods of analysis (DePaul Symptom Questionnaire 2 (DSQ-2), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and machine learning techniques).Items assessing onset and severity for individuals who reported having PPS were found to have experienced an onset of PPS related symptoms roughly 30 years after the onset of Polio. Items found in the DSQ-2, SF-36 compared all illness groups and found that participants with ME/CFS were more functionally impaired across symptoms than those with PPS. Across all analyses, three domains most commonly differentiated the illnesses (neurocognitive, Post-exertional malaise, and neuroendocrine).Examining functional impairment amongst chronically fatiguing illnesses using multiple methods of analysis can be an important factor in distinguishing similar illnesses. These findings support further analysis of analogous symptomatology among other chronic illnesses to assist in diagnosis.
View details for DOI 10.1080/21641846.2019.1687117
View details for PubMedID 33014628
View details for PubMedCentralID PMC7531614
Myalgic encephalomyelitis and chronic fatigue syndrome case definitions: effects of requiring a substantial reduction in functioning
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2019; 7 (2): 59–68
Current case definitions for myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) require an individual to report a 'substantial reduction' in activity levels, when compared to premorbid functioning. However, little guidance is provided on how to measure these reductions, as well as what level of reduction should be deemed 'substantial,' leading to inconsistencies in how this criterion is applied across research settings.The current study examined the influence of substantial reduction criterion on case definitions.The current study analyzed an international convenience sample of 1002 individuals with ME or CFS, 53 healthy controls, and 260 controls with other chronic illnesses.Findings indicated that the utility of the substantial reduction criterion varied by case definition, with more stringent case definitions not needing this criterion to identify cases.These results suggest that the requirement of a substantial reduction in functioning may be redundant when case definitions specify that individuals must endorse a set of core symptoms at specified frequency and severity levels.
View details for DOI 10.1080/21641846.2019.1600825
View details for Web of Science ID 000495424500001
View details for PubMedID 31788347
View details for PubMedCentralID PMC6884336
The DePaul Symptom Questionnaire-2: a validation study
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2019; 7 (3): 166–79
The DePaul Symptom Questionnaire (DSQ) was developed to assess the symptomatology and case definition fulfillment of individuals with myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). The questionnaire was recently revised to improve its psychometric properties, increase its diagnostic reliability, and assess symptoms required by case definitions. The resulting instrument was named the DSQ-2.The current study sought to evaluate the utility and reliability of the new and revised items in the DSQ-2.A cross-sectional sample of 399 adults with ME or CFS was recruited to complete the DSQ-2.Descriptive analyses of the DSQ-2 suggest that the new and revised items enhance the instrument's ability to assess certain symptom domains and evaluate recent case definitions. Additionally, an exploratory factor analysis resulted in an eight-factor solution: post-exertional malaise, cognitive impairment, fever and flu, pain, sleep disruption, orthostatic intolerance, genitourinary issues, and temperature intolerance. The items within each factor demonstrated strong internal consistency reliability (Cronbach's alphas = .73-.91).These analyses indicate that the DSQ-2 offers a more thorough and precise understanding ME and CFS symptomology and case definition fulfillment.
View details for DOI 10.1080/21641846.2019.1653471
View details for Web of Science ID 000489317700005
View details for PubMedID 32685281
View details for PubMedCentralID PMC7367506
The Development of the DePaul Symptom Questionnaire: Original, Expanded, Brief, and Pediatric Versions
FRONTIERS IN PEDIATRICS
2018; 6: 330
One of the key requirements of a reliable case definition is the use of standardized procedures for assessing symptoms. This article chronicles the development of the DePaul Symptom Questionnaire (DSQ) to assess symptoms of the major chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) case definitions. The original questionnaire has been modified and expanded over time to more fully capture symptoms from various adult case definitions, and a brief as well as pediatric version have also been developed. The DSQ has demonstrated very good psychometric properties in terms of test-retest reliability and sensitivity/specificity, as well as construct, predictive, and discriminant validity. The DSQ allows for a clear characterization of a patient's illness and allows scientists and clinicians to improve diagnostic reliability and validity when employing case definitions of ME and CFS.
View details for DOI 10.3389/fped.2018.00330
View details for Web of Science ID 000449344300001
View details for PubMedID 30460215
View details for PubMedCentralID PMC6232226
The development of an instrument to assess post-exertional malaise in patients with myalgic encephalomyelitis and chronic fatigue syndrome.
Journal of health psychology
Post-exertional malaise, or a variation of this term, is a key symptom of myalgic encephalomyelitis and chronic fatigue syndrome, as this symptom is mentioned in almost all myalgic encephalomyelitis and chronic fatigue syndrome case definitions. Until now there has not been a comprehensive questionnaire to assess post-exertional malaise. To rectify this situation, in this article we describe the development of a new questionnaire, called the DePaul Post-Exertional Malaise Questionnaire, which was based on input from hundreds of patients. Preliminary validation was provided by the findings of significant and predictable relationships between different domains of this post-exertional malaise questionnaire and physical functioning.
View details for DOI 10.1177/1359105318805819
View details for PubMedID 30354489
A reexamination of the cognitive behavioral model of chronic fatigue syndrome
JOURNAL OF CLINICAL PSYCHOLOGY
2018; 74 (7): 1234–45
The cognitive behavioral model of chronic fatigue syndrome (CFS) suggests that cognitions and reduced activity level perpetuate the fatigue and impairment that individuals with CFS experience. The two empirical evaluations of this model resulted in conflicting findings. The current study examines the influence of case definition fulfillment on the applicability of this model to CFS.A moderated mediation analysis was conducted on 990 individuals with CFS to reexamine the behavioral pathway of this model. Case definition fulfillment was entered as a moderator.Findings were generally inconsistent with the cognitive behavioral model of CFS. Case definition fulfillment significantly moderated the relation between activity level and physical impairment (β = -0.08, p = 0.03); individuals who met more stringent case definitions demonstrated a weaker relation between activity level and impairment.This model may not accurately represent the experience of individuals with CFS, particularly those who fulfill more stringent case definitions.
View details for DOI 10.1002/jclp.22593
View details for Web of Science ID 000435275800012
View details for PubMedID 29457646
View details for PubMedCentralID PMC6002889
- Identifying subtypes of ME and CFS: a rebuttal FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR 2018; 6 (4): 237–38
Latent class analysis of a heterogeneous international sample of patients with myalgic encephalomyelitis/chronic fatigue syndrome
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2018; 6 (3): 163–78
Individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) routinely display differences in symptomatology, as well as illness course, onset, duration, and functional disability. Given such diversity, previous work has attempted to identify symptom-based ME/CFS subtypes. However, results have been inconsistent.This study sought to elucidate potential subtypes of ME/CFS as well as explore the impact of subtype membership on health functioning.Twelve non-core (i.e., less frequently endorsed) symptoms were included in a latent class analysis of 1,210 adults with ME/CFS. Demographic and illness-related predictors of class membership were evaluated with a multinomial logistic regression. ANOVAs were then performed to determine if there were significant differences across class on the eight subscales of the Short-Form Health Survey (SF-36).A six-class solution was selected, which consisted of one class that was likely to endorse all non-core symptoms, one class that was unlikely to endorse any non-core symptoms, and four classes that were likely to endorse either one or two non-core symptom domains (i.e., circulatory/neuroendocrine impairment, orthostatic intolerance, and gastro-intestinal distress). Significant functioning differences by class were present for all SF-36 subscales.These results are suggestive of subtypes of ME/CFS and, if replicated, may assist physicians in providing tailored treatment to patients and allow researchers to form more homogeneous samples.
View details for DOI 10.1080/21641846.2018.1494530
View details for Web of Science ID 000455412700005
View details for PubMedID 31435490
View details for PubMedCentralID PMC6703845
Are current chronic fatigue syndrome criteria diagnosing different disease phenotypes?
2017; 12 (10): e0186885
Chronic fatigue syndrome (CFS) is characterised by a constellation of symptoms diagnosed with a number of different polythetic criteria. Heterogeneity across these diagnostic criteria is likely to be confounding research into the as-yet-unknown pathophysiology underlying this stigmatised and debilitating condition and may diagnose a disease spectrum with significant implications for clinical management. No studies to date have objectively investigated this possibility using a validated measure of CFS symptoms-the DePaul Symptom Questionnaire (DSQ).To examine whether current CFS diagnostic criteria are identifying different disease phenotypes using the DSQ.Case control study.Clinical Research Facility of the Royal Victoria Infirmary, Newcastle upon Tyne, UK.49 CFS subjects and ten matched, sedentary community controls, excluded for co-morbid depression.Self-reported autonomic and cognitive features were assessed with the Composite Autonomic Symptom Score (COMPASS) and Cognitive Failures Questionnaire (COGFAIL) respectively. Objective autonomic cardiovascular parameters were examined using the Task Force® Monitor and a battery of neuropsychological tests administered for objective cognitive assessment.Self-reported autonomic and cognitive symptoms were significantly greater in CFS subjects compared to controls. There were no statistically significant differences in objective autonomic measures between CFS and controls. There were clinically significant differences between DSQ subgroups on objective autonomic testing. Visuospatial memory, verbal memory and psychomotor speed were significantly different between DSQ subgroups.The finding of no significant differences in objective autonomic testing between CFS and control subjects may reflect the inclusion of sedentary controls or exclusion for co-morbid depression. Consistent exclusion criteria would enable better delineation of these two conditions and their presenting symptoms. Findings across CFS subgroups suggest subjects have a different disease burden on subjective and objective measures of function, autonomic parameters and cognitive impairment when categorised using the DSQ. Different CFS criteria may at best be diagnosing a spectrum of disease severities and at worst different CFS phenotypes or even different diseases. This complicates research and disease management and may contribute to the significant stigma associated with the condition.
View details for DOI 10.1371/journal.pone.0186885
View details for Web of Science ID 000413315100047
View details for PubMedID 29053742
View details for PubMedCentralID PMC5650174
Access to Medical Care for Individuals with Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: A Call for Centers of Excellence.
Modern clinical medicine research
2017; 1 (1): 28–35
The current study sought to better understand the experience of individuals with myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) in accessing care for their debilitating illness. Of 898 participants, less than half had ever seen an ME or CFS specialist, though 99% of participants were interested in specialist care. Participants cited geographic and financial barriers as most frequently precluding access to specialists. Furthermore, satisfaction with specialist care greatly exceeded satisfaction with non-specialist care. These findings suggested that individuals with ME and CFS represent a medically-underserved population, due to lack of available care. The CFS Advisory Committee and NIH Pathways to Prevention Working Group recommended the creation of ME and CFS Centers of Excellence to improve the healthcare access of patients with ME and CFS. The current study documents the need for these centers, as they would ameliorate geographic and financial barriers to quality care.
View details for DOI 10.22606/mcmr.2017.11005
View details for PubMedID 28713878
A Comparison of Case Definitions for Myalgic Encephalomyelitis and Chronic Fatigue Syndrome.
Journal of chronic diseases and management
2017; 2 (2)
Many professionals have described the clinical presentation of myalgic encephalomyelitis (ME), but recent efforts have focused on the development of ME criteria that can be reliably applied. The current study compared the symptoms and functioning of individuals who met the newly-developed Institute of Medicine (IOM) clinical criteria to a revised version of the London criteria for ME. While 76% of a sample diagnosed with chronic fatigue syndrome (CFS) met the IOM criteria, 44% met the revised London criteria. The revised London criteria identified patients with greater physical impairment. The results of this study indicate the need for a standard case definition with specific guidelines for operationalization. The application of case definitions has important implications for the number of individuals identified with ME, the pattern of symptoms experienced by these individuals, and the severity of their symptoms and functional limitations. Sample heterogeneity across research studies hinders researchers from replicating findings and impedes the search for biological markers and effective treatments.
View details for PubMedID 29104961
Examining those Meeting IOM Criteria Versus IOM Plus Fibromyalgia.
2017; 5 (1): 19–28
The Institute of Medicine (IOM) recently developed clinical criteria for chronic fatigue syndrome (CFS). There might be additional criteria that could select a more homogenous and impaired group of patients, particularly those with pain. The current study focused on criteria which involved meeting the four IOM criteria, excluding medical and psychiatric co-morbidities, along with having fibromyalgia (FM). Findings indicated that those meeting the IOM clinical criteria plus FM were more impaired on a wide variety of symptoms and functional areas than those meeting on the IOM criteria or those with just 6 months of fatigue. The implications of using such research criteria are discussed.
View details for PubMedID 28713879
A Prospective Study of Infectious Mononucleosis in College Students.
International journal of psychiatry (Overland Park)
2017; 2 (1)
BACKGROUND: The present study aims to prospectively investigate possible biological and psychological factors present in college students who will go on to develop chronic fatigue syndrome (CFS) following Infectious Mononucleosis (IM). Identification of risk factors predisposing patients towards developing CFS may help to understand the underlying mechanisms and ultimately prevent its occurrence. Our study is enrolling healthy college students over the age of 18. Enrollment began in March of 2013 and is ongoing.METHODS: Biological and psychological data are collected when students are well (Stage 1), when they develop IM (Stage 2), and approximately 6 months after IM diagnosis (Stage 3).RESULTS: Two case studies demonstrate the progression of student symptomology across all three stages.CONCLUSION: The Case Studies presented illustrate the usefulness of a prospective research design that tracks healthy students, following their trajectory of IM illness to either a) full recovery or b) diagnosis with CFS.
View details for PubMedID 28717787
Clinical criteria versus a possible research case definition in chronic fatigue syndrome/myalgic encephalomyelitis
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2017; 5 (2): 89–102
The Institute of Medicine (IOM) recently developed clinical criteria for what had been known as chronic fatigue syndrome (CFS). Given the broad nature of the clinical IOM criteria, there is a need for a research definition that would select a more homogenous and impaired group of patients than the IOM clinical criteria. At the present time, it is unclear what will serve as the research definition.The current study focused on a research definition which selected homebound individuals who met the four IOM criteria, excluding medical and psychiatric co-morbidities.Our research criteria were compared to those participants meeting the IOM criteria. Those not meeting either of these criteria sets were placed in a separate group defined by 6 or more months of fatigue. Data analyzed were from the DePaul Symptom Questionnaire and the SF-36. Due to unequal sample sizes and variances, Welch's F tests and Games-Howell post hoc tests were conducted.Using a large database of over 1,000 patients from several countries, we found that those meeting a more restrictive research definition were even more impaired and more symptomatic than those meeting criteria for the other two groups.Deciding on a particular research case definition would allow researchers to select more comparable patient samples across settings, and this would represent one of the most significant methodologic advances for this field of study.
View details for DOI 10.1080/21641846.2017.1299077
View details for Web of Science ID 000411653100002
View details for PubMedID 29062593
View details for PubMedCentralID PMC5650200
Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome
2016; 12 (4): 292–307
The objective of this study was to examine individuals with myalgic encephalomyelitis and chronic fatigue syndrome who are confined to their homes due to severe symptomatology. The existing literature fails to address differences between this group, and less severe, nonhousebound patient populations.Participants completed the DePaul Symptom Questionnaire, a measure of myalgic encephalomyelitis and chronic fatigue syndrome symptomology, and the SF-36, a measure of health impact on physical/mental functioning. ANOVAs and, where appropriate, MANCOVAS were used to compare housebound and nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome across areas of functioning, symptomatology, and illness onset characteristics.Findings indicated that the housebound group represented one quarter of the sample, and were significantly more impaired with regards to physical functioning, bodily pain, vitality, social functioning, fatigue, postexertional malaise, sleep, pain, neurocognitive, autonomic, neuroendocrine, and immune functioning compared to individuals who were not housebound.Findings indicated that housebound patients have more impairment on functional and symptom outcomes compared to those who were not housebound. Understanding the differences between housebound and not housebound groups holds implications for physicians and researchers as they develop interventions intended for patients who are most severely affected by this chronic illness.
View details for DOI 10.1177/1742395316644770
View details for Web of Science ID 000433666900005
View details for PubMedID 27127189
View details for PubMedCentralID PMC5464362
Identifying Key Symptoms Differentiating Myalgic Encephalomyelitis and Chronic Fatigue Syndrome from Multiple Sclerosis.
2016; 4 (2): 41–45
It is unclear what key symptoms differentiate Myalgic Encephalomyelitis (ME) and Chronic Fatigue syndrome (CFS) from Multiple Sclerosis (MS). The current study compared self-report symptom data of patients with ME or CFS with those with MS. The self-report data is from the DePaul Symptom Questionnaire, and participants were recruited to take the questionnaire online. Data were analyzed using a machine learning technique called decision trees. Five symptoms best differentiated the groups. The best discriminating symptoms were from the immune domain (i.e., flu-like symptoms and tender lymph nodes), and the trees correctly categorized MS from ME or CFS 81.2% of the time, with those with ME or CFS having more severe symptoms. Our findings support the use of machine learning to further explore the unique nature of these different chronic diseases.
View details for PubMedID 28066845
Are Myalgic Encephalomyelitis and chronic fatigue syndrome different illnesses? A preliminary analysis
JOURNAL OF HEALTH PSYCHOLOGY
2016; 21 (1): 3–15
Considerable discussion has transpired regarding whether chronic fatigue syndrome is a distinct illness from Myalgic Encephalomyelitis. A prior study contrasted the Myalgic Encephalomyelitis International Consensus Criteria with the Fukuda and colleagues' chronic fatigue syndrome criteria and found that the Myalgic Encephalomyelitis International Consensus Criteria identified a subset of patients with greater functional impairment and physical, mental, and cognitive problems than the larger group who met Fukuda and colleagues' criteria. The current study analyzed two discrete data sets and found that the Myalgic Encephalomyelitis International Consensus Criteria identified more impaired individuals with more severe symptomatology.
View details for DOI 10.1177/1359105313520335
View details for Web of Science ID 000367333200001
View details for PubMedID 24510231
View details for PubMedCentralID PMC4125561
Case definitions integrating empiric and consensus perspectives
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2016; 4 (1): 1–23
There has been considerable controversy regarding how to name and define the illnesses known as myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). The IOM report has proposed a new clinical criteria and name for this illness, but aspects of these recommendations have been scrutinized by patients and scientists.It is possible that both empiric and consensus approaches could be used to help settle some of these diagnostic challenges. Using patient samples collected in the United States, Great Britain, and Norway (N=556), the current study attempted to categorize patients using more general as well as more restricted case definitions.Overall, the outcomes suggest that there might be four groupings of patients, with the broadest category involving those with chronic fatigue (N=62), defined by 6 or more months of fatigue which can be cannot be explained by medical or psychiatric conditions. A second category involves those patients that have chronic fatigue that can be explained by a medical or psychiatric condition (N=47). A third category involves more specific criteria that have been posited both by the IOM report, a Canadian Clinical Case criteria, a ME-ICC criteria and a more empiric approach. These efforts have specified domains of substantial reductions of activity, post-exertional malaise, neurocognitive impairment, and sleep dysfunction (N=346). Patients with these characteristics were more functionally impaired than those meeting just chronic fatigue criteria, p < .05. Finally, those meeting even more restrictive ME criteria proposed by Ramsay, identified a smaller and even more impaired group, p < .05.The advantages of using such empirical and consensus approaches to develop reliable classification and diagnostic efforts are discussed.
View details for DOI 10.1080/21641846.2015.1124520
View details for Web of Science ID 000382030000001
View details for PubMedID 27088059
View details for PubMedCentralID PMC4831204
- Comparing the DePaul Symptom Questionnaire with physician assessments: a preliminary study FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR 2016; 4 (1): 52–62
Issues in Estimating Rates of Pediatric Chronic Fatigue Syndrome and Myalgic Encephalomyelitis in a Community-based Sample.
Avicenna journal of neuropsychophysiology
2015; 2 (4)
There is a need to examine the prevalence of pediatric chronic fatigue syndrome (CFS) and Myalgic Encephalomyelitis (ME) in the general community, as well as the relative frequency of CFS and ME among various groups (e.g., different age groups, genders, racial/ethnic groups, and socioeconomic strata) and to compare these individuals with community controls. In the present study, we describe an ongoing NIH-funded study, which uses a multiple-stage design, beginning with a brief screening for CFS- and ME-like symptomatology, followed by a more rigorous medical and psychiatric diagnostic evaluation to determine the prevalence of pediatric CFS and ME status in the general community. We provide two case studies showing the types of data we are collecting, and how the data are being used to inform diagnostic decisions.
View details for DOI 10.17795/ajnpp-37281
View details for PubMedID 28261672
Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains.
Journal of neurology and neurobiology
2015; 1 (4)
The present study attempted to identify critical symptom domains of individuals with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Using patient and control samples collected in the United States, Great Britain, and Norway, exploratory factor analysis (EFA) was used to establish the underlying factor structure of ME and CFS symptoms. The EFA suggested a four-factor solution: post-exertional malaise, cognitive dysfunction, sleep difficulties, and a combined factor consisting of neuroendocrine, autonomic, and immune dysfunction symptoms. The use of empirical methods could help better understand the fundamental symptom domains of this illness.
View details for DOI 10.16966/2379-7150.114
View details for PubMedID 27088131
Defining Essential Features of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome
JOURNAL OF HUMAN BEHAVIOR IN THE SOCIAL ENVIRONMENT
2015; 25 (6): 657–74
Considerable debate surrounds the search for the defining features of patients with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Current case definitions were created through clinical consensus. Failure to operationalize these case definitions has led to considerable variability in the identification of patients. In addition, some case definitions (e.g., Fukuda et al., 1994) do not require cardinal symptoms of this illness, where as other case definitions do require core symptoms of this illness (Carruthers et al., 2003, 2011), and these latter case criteria appear to identify a more impaired group of patients. Criterion variance is most likely to occur when operationally explicit criteria do not exist for diagnostic categories (Spitzer, Endicott, & Robins, 1978), or when there are varying criteria for contrasting case definitions, which is an impediment to the research in this field. To deal with this problem, it is possible to differentiate those that meet more loosely defined criteria from those that are more narrowly and defined, thus differentiating CFS from ME. In order to progress the search for biological markers and effective treatments, essential features need to be operationalized and broadly used in order to increase the probability that individuals included in samples have the same underlying illness.
View details for DOI 10.1080/10911359.2015.1011256
View details for Web of Science ID 000356362400011
View details for PubMedID 27047234
View details for PubMedCentralID PMC4817848
Unintended Consequences of not Specifying Exclusionary Illnesses for Systemic Exertion Intolerance Disease
2015; 5 (2): 272–86
The Institute of Medicine recently proposed a new case definition for chronic fatigue syndrome (CFS), as well as a new name, Systemic Exertion Intolerance Disease (SEID). Contrary to the Fukuda et al.'s CFS case definition, there are few exclusionary illnesses specified for this new SEID case definition. The current study explored this decision regarding exclusionary illnesses using the SEID criteria with four distinct data sets involving patients who had been identified as having CFS, as well as healthy controls, community controls, and other illness groups. The findings indicate that many individuals from major depressive disorder illness groups as well as other medical illnesses were categorized as having SEID. The past CFS Fukuda et al. prevalence rate in a community based sample of 0.42 increased by 2.8 times with the new SEID criteria. The consequences for this broadening of the case definition are discussed.
View details for DOI 10.3390/diagnostics5020272
View details for Web of Science ID 000361114500010
View details for PubMedID 26854153
View details for PubMedCentralID PMC4666441
Examining the Institute of Medicine's Recommendations Regarding Chronic Fatigue Syndrome: Clinical Versus Research Criteria.
Journal of neurology and psychology
2015; 2015 (Suppl 2)
The Institute of Medicine (2015) has proposed a new clinical case definition for what had been known as chronic fatigue syndrome (CFS). This new criteria involved the following domains: substantial reduction or impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities; post-exertional malaise; unrefreshing sleep; and at least one of the two following symptoms: cognitive impairment or orthostatic intolerance. In addition, in August of 2015, the CFS Advisory Committee, which makes recommendations to the Secretary of US Department of Health and Human Services, proposed that the Canadian 2003 criteria should serve as the research case for CFS. Up to now, there have not been any published investigations comparing these clinical and research criteria. Using patient samples collected in the United States, Great Britain, and Norway, the current study compared and contrasted patients who met the clinical and research criteria. Overall findings indicated that those meeting the research criteria in comparison to those meeting the clinical criteria were significantly more impaired on a wide variety of symptoms and functional areas. The implications of these findings are discussed.
View details for PubMedID 27595126
Chronic Fatigue Syndrome Versus Sudden Onset Myalgic Encephalomyelitis
JOURNAL OF PREVENTION & INTERVENTION IN THE COMMUNITY
2015; 43 (1): 62–77
A revised sudden onset case definition for Myalgic Encephalomyelitis (ME) has been developed (Jason, Damrongvachiraphan, et al., 2012 ) based on past case definitions. In a prior study, Jason, Brown, and colleagues ( 2012 ) compared patients recruited using the 1994 case definition of chronic fatigue syndrome (CFS) to contrast those meeting criteria for the revised ME criteria. They found that this revised ME case definition identified patients with more functional impairments and physical, mental, and cognitive problems than those meeting the CFS criteria. The study by Jason, Brown, et al. ( 2012 ) only selected individuals who first met the CFS criteria, and it only relied on one Chicago-based data set. The current study replicated this comparison with two distinct data sets with different case ascertainment methods. Results indicate that the ME criteria identified a group of patients with more functional disabilities as well as more severe post-exertional malaise symptoms.
View details for DOI 10.1080/10852352.2014.973233
View details for Web of Science ID 000212560800007
View details for PubMedID 25584529
View details for PubMedCentralID PMC4295655
Complications in Operationalizing Lifelong Fatigue as an Exclusionary Criterion
JOURNAL OF PREVENTION & INTERVENTION IN THE COMMUNITY
2015; 43 (1): 42–53
The case definitions for chronic fatigue syndrome (CFS) and chronic fatigue syndrome/Myalgic Encephalomyelitis (ME) stipulate that the experience of lifelong fatigue is an exclusionary criterion (Carruthers et al., 2003 ; Fukuda et al., 1994 ). This article examines the lifelong fatigue construct and identifies potential validity and reliability issues in using lifelong fatigue as an exclusionary condition. Participants in the current study completed the DePaul Symptom Questionnaire (Jason et al., 2010 ), and responses were examined to determine if they had experienced lifelong fatigue. This article discusses the extensive process that was needed to confidently discern which participants had or did not have lifelong fatigue. Using the most rigorous standards, few individuals were classified as having lifelong fatigue. In addition, those with and without lifelong fatigue had few significant differences in symptoms and functional areas. This article concludes with a recommendation that lifelong fatigue should no longer be used as an exclusionary criterion for CFS or ME/CFS.
View details for DOI 10.1080/10852352.2014.973238
View details for Web of Science ID 000212560800005
View details for PubMedID 25584527
View details for PubMedCentralID PMC4295633
- An Overview of Operationalizing Criteria for ME, ME/CFS, and CFS Case Definitions Introduction JOURNAL OF PREVENTION & INTERVENTION IN THE COMMUNITY 2015; 43 (1): 1–4
Chronic fatigue syndrome and myalgic encephalomyelitis: towards an empirical case definition
HEALTH PSYCHOLOGY AND BEHAVIORAL MEDICINE
2015; 3 (1): 82–93
Current case definitions of Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS) have been based on consensus methods, but empirical methods could be used to identify core symptoms and thereby improve the reliability. In the present study, several methods (i.e., continuous scores of symptoms, theoretically and empirically derived cut off scores of symptoms) were used to identify core symptoms best differentiating patients from controls. In addition, data mining with decision trees was conducted. Our study found a small number of core symptoms that have good sensitivity and specificity, and these included fatigue, post-exertional malaise, a neurocognitive symptom, and unrefreshing sleep. Outcomes from these analyses suggest that using empirically selected symptoms can help guide the creation of a more reliable case definition.
View details for DOI 10.1080/21642850.2015.1014489
View details for Web of Science ID 000409568800007
View details for PubMedID 26029488
View details for PubMedCentralID PMC4443921
Reflections on the Institute of Medicine's systemic exertion intolerance disease
POLSKIE ARCHIWUM MEDYCYNY WEWNETRZNEJ-POLISH ARCHIVES OF INTERNAL MEDICINE
2015; 125 (7-8): 576–81
The Institute of Medicine (IOM) in the United States has recently proposed that the term systemic exertion intolerance disease (SEID) replace chronic fatigue syndrome. In addition, the IOM proposed a new case definition for SEID, which includes substantial reductions or impairments in the ability to engage in pre‑illness activities, unrefreshing sleep, postexertional malaise, and either cognitive impairment or orthostatic intolerance. Unfortunately, these recommendations for a name change were not vetted with patient and professional audiences, and the new criteria were not evaluated with data sets of patients and controls. A recent poll suggests that the majority of patients reject this new name. In addition, studies have found that prevalence rates will dramatically increase with the new criteria, particularly due to the ambiguity revolving around exclusionary illnesses. Findings suggest that the new criteria select more patients who have less impairment and fewer symptoms than several other criteria. The implications of these findings are discussed in the current review.
View details for DOI 10.20452/pamw.2973
View details for Web of Science ID 000361947000015
View details for PubMedID 26176405
View details for PubMedCentralID PMC4826027
Test-retest reliability of the DePaul Symptom Questionnaire
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2015; 3 (1): 16–32
The DePaul Symptom Questionnaire (DSQ) was developed to provide a structured approach for collecting standardized symptomatology and health history information to allow researchers and clinicians to determine whether a patient meets the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), myalgic encephalomyelitis (ME), and/or chronic fatigue syndrome (CFS).The purpose of this study was to examine the test-retest reliability of the DSQ.Test-retest reliability of the measure was examined with a sample of 26 adults self-identifying as having either ME/CFS, ME and/or CFS and 25 adults who did not self-identify as having these illnesses and were otherwise healthy controls.Overall, the majority of items on the DSQ exhibited good to excellent test-retest reliability, with Pearson's or kappa correlation coefficients that were 0.70 or higher.Thus, the present study suggests that the DSQ is a reliable diagnostic measure that can provide a standardized way of examining illness constructs and symptomatology among patients who identify as having ME/CFS, ME and/or CFS.
View details for DOI 10.1080/21641846.2014.978110
View details for Web of Science ID 000218592900002
View details for PubMedID 26973799
View details for PubMedCentralID PMC4788471
Chronic fatigue syndrome versus systemic exertion intolerance disease
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2015; 3 (3): 127–41
The Institute of Medicine has recommended a change in the name and criteria for Chronic Fatigue Syndrome (CFS), renaming the illness Systemic Exertion Intolerance Disease (SEID). The new SEID case definition requires substantial reductions or impairments in the ability to engage in pre-illness activities, unrefreshing sleep, post-exertional malaise, and either cognitive impairment or orthostatic intolerance.In the current study, samples were generated through several different methods and were used to compare this new case definition to previous case definitions for CFS, Myalgic Encephalomyelitis (ME-ICC), Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), as well as a case definition developed through empirical methods.We used a cross-sectional design with samples from tertiary care settings, a biobank sample, and other forums. 796 patients from the US, Great Britain, and Norway completed the DePaul Symptom Questionnaire.Findings indicated that the SEID criteria identified 88% of participants in the samples analyzed, which is comparable to the 92% that met the Fukuda criteria. The SEID case definition was compared to a four item empiric criteria, and findings indicated that the four item empiric criteria identified a smaller, more functionally limited and symptomatic group of patients.The recently developed SEID criteria appears to identify a group comparable in size to the Fukuda et al. criteria, but a larger group of patients than the Canadian ME/CFS and ME criteria, and selects more patients who have less impairment and fewer symptoms than a four item empiric criteria.
View details for DOI 10.1080/21641846.2015.1051291
View details for Web of Science ID 000218604900001
View details for PubMedID 26345409
View details for PubMedCentralID PMC4556426
- Comparing and contrasting consensus versus empirical domains FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR 2015; 3 (2): 63–74
Comparing and Contrasting Consensus versus Empirical Domains.
Fatigue : biomedicine, health & behavior
2014; 3 (2): 63–74
BACKGROUND: Since the publication of the CFS case definition , there have been a number of other criteria proposed including the Canadian Consensus Criteria  and the Myalgic Encephalomyelitis: International Consensus Criteria. .PURPOSE: The current study compared these domains that were developed through consensus methods to one obtained through more empirical approaches using factor analysis.METHODS: Using data mining, we compared and contrasted fundamental features of consensus-based criteria versus empirical latent factors. In general, these approaches found the domain of Fatigue/Post-exertional malaise as best differentiating patients from controls.RESULTS: Findings indicated that the Fukuda et al. criteria had the worst sensitivity and specificity.CONCLUSIONS: These outcomes might help both theorists and researchers better determine which fundamental domains to be used for the case definition.
View details for PubMedID 26977374
Examining case definition criteria for chronic fatigue syndrome and myalgic encephalomyelitis
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2014; 2 (1): 40–56
Considerable controversy has transpired regarding the core features of myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Current case definitions differ in the number and types of symptoms required. This ambiguity impedes the search for biological markers and effective treatments.This study sought to empirically operationalize symptom criteria and identify which symptoms best characterize the illness.Patients (n=236) and controls (n=86) completed the DePaul Symptom Questionnaire, rating the frequency and severity of 54 symptoms. Responses were compared to determine the threshold of frequency/severity ratings that best distinguished patients from controls. A Classification and Regression Tree (CART) algorithm was used to identify the combination of symptoms that most accurately classified patients and controls.A third of controls met the symptom criteria of a common CFS case definition when just symptom presence was required; however, when frequency/severity requirements were raised, only 5% met criteria. Employing these higher frequency/severity requirements, the CART algorithm identified three symptoms that accurately classified 95.4% of participants as patient or control: fatigue/extreme tiredness, inability to focus on multiple things simultaneously, and experiencing a dead/heavy feeling after starting to exercise.Minimum frequency/severity thresholds should be specified in symptom criteria to reduce the likelihood of misclassification. Future research should continue to seek empirical support of the core symptoms of ME and CFS to further progress the search for biological markers and treatments.
View details for DOI 10.1080/21641846.2013.862993
View details for Web of Science ID 000218587400005
View details for PubMedID 24511456
View details for PubMedCentralID PMC3912876
Energy conservation/envelope theory interventions
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2013; 1 (1-2): 27–42
Treatment approaches for patients with Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) have been controversial. This paper provides the theoretical and conceptual background for the Energy Envelope Theory to assist patients with ME/CFS and reviews evidence of its treatment efficacy.Over a 15-year period, efforts were directed to develop a non-pharmacologic intervention that endeavored to help patients with ME/CFS self-monitor and self-regulate energy expenditures and learn to pace activities and stay within their energy envelope.Studies show that the energy envelope approach, which involves rehabilitation methods, helps patients with ME/CFS pace activities and manage symptoms and can significantly improve their quality of life.
View details for DOI 10.1080/21641846.2012.733602
View details for Web of Science ID 000218584200004
View details for PubMedID 23504301
View details for PubMedCentralID PMC3596172
Contrasting chronic fatigue syndrome versus myalgic encephalomyelitis/chronic fatigue syndrome
FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR
2013; 1 (3): 168–83
Much debate is transpiring regarding whether chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) are different illnesses. Several prior studies that compared the Fukuda et al. CFS criteria to the Canadian ME/CFS criteria found that the Canadian criteria identified patients with more functional impairments and greater physical, mental, and cognitive problems than those who met Fukuda et al. criteria.[3,4] These samples were located in the Chicago metropolitan area, so the results could not be generalized to other locations. In addition, past studies used a symptom questionnaire that was not specifically developed to tap the Canadian criteria.The present comparative study of CFS and ME/CFS criteria was intended to correct the methodological problems of prior studies.This article used data from three distinct samples to compare patients who met criteria for the ME/CFS Canadian clinical case definition  to those who met the Fukuda et al. CFS case definition..Findings indicated that fewer individuals met the Canadian criteria than the Fukuda et al. criteria. Those who met the Canadian criteria evidenced more severe symptoms and physical functioning impairment.Future research should continue to compare existing case definitions and determine which criteria best select for this illness.
View details for DOI 10.1080/21641846.2013.774556
View details for Web of Science ID 000218585200005
View details for PubMedID 23914329
View details for PubMedCentralID PMC3728084