Latent class analysis of symptoms associated with chronic fatigue syndrome and fibromyalgia

P. F. SULLIVAN, W. SMITH, D. BUCHWALD
2002 Psychological Medicine  
Background. Chronic fatigue syndrome and fibromyalgia continue to be perplexing conditions of unknown validity. Aetiological and symptomatic heterogeneity is likely and the distinctiveness of these disorders remains unclear. Our aims were to investigate empirically symptomatic heterogeneity in chronic fatigue syndrome and fibromyalgia. Methods. Latent class analysis was applied to data from 646 patients who met accepted criteria for chronic fatigue syndrome and\or fibromyalgia who were
more » ... cally evaluated at a specialist fatigue clinic. Thirty-two symptoms commonly found in chronic fatigue syndrome and fibromyalgia were entered into the latent class analysis. Results. We chose to interpret a four class solution. The classes appeared to differ in a graded fashion (rather than qualitatively) for symptom endorsements, pre-morbid characteristics, and comorbidity with panic disorder and major depression. Conclusions. These results were unexpected given the usual assumption of the distinctiveness of chronic fatigue syndrome and fibromyalgia. These results support a conceptualization of chronic fatigue syndrome and fibromyalgia as being characterized by greater similarities than differences.
doi:10.1017/s0033291702005834 pmid:12171382 fatcat:f6q23vfdr5ghfdnbgmavsr4kse