Worsening vs.improving groups in long-term ME/CFS

The worsening (n = 128) and improving (n = 70) group of long-term patients were well differentiated on measures of ME/CFS symptom severity, stress, depression and functional status. The age at onset was significantly lower (27.5 vs. 32.5) and the duration of illness significantly longer (20.5 years vs. 17.4 years) in the worsening group.

The worsening subgroup was also significantly more likely to report the co-morbid conditions of fibromyalgia, chronic sinus infections, thyroid problems, asthma and previous suicide attempt. The worsening group was significantly less likely to endorse "persistent stress" as a perceived initial cause of ME/CFS, although this group showed elevated levels of stress and depression.

Unexpectedly, the worsening group of CFIDS patients showed significantly lower symptom severity scores than the improving group during the first year of CFIDS. This is a result other researchers should look into.

No significant differences between the groups were found in age, sex, education, social support scores, or on the type of illness onset reported (sudden or gradual). The symptom measures of allergy severity and chemical sensitivity were not significantly different between the two groups. 83.3% of the worsening group could not work, while 51.5% of the improving group could not do so.