Latent class analysis of a heterogeneous international sample of patients with myalgic encephalomyelitis/chronic fatigue syndrome

ABSTRACT

Background: 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.

Purpose: This study sought to elucidate potential subtypes of ME/CFS as well as explore the impact of subtype membership on health functioning.

Methods: 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).

Results: 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.

Conclusions: 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.

KEYWORDS:

• Myalgic encephalomyelitis
• chronic fatigue syndrome
• subtypes
• latent class analysis
• health functioning

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development under [grant number HD073308].

Notes on contributors

Kayla A. Huber

Kayla A. Huber is a research assistant at the Center for Community Research.

Madison Sunnquist

Madison Sunnquist is a doctoral candidate in Clinical-Community Psychology at DePaul University as well as a Project Director at the Center for Community Research.

Leonard A. Jason

Leonard A. Jason is a Professor of Psychology at DePaul University and has served as Director of the Center for Community Research since 2001.