Functional status in patients with chronic fatigue syndrome, other fatiguing illnesses, and healthy individuals, 1996, Buchwald et al

Functional status in patients with chronic fatigue syndrome, other fatiguing illnesses, and healthy individuals

Abstract
Background
Chronic fatigue syndrome (CFS) is a condition that may be associated with substantial disability. The Medical Outcomes Study Short-Form General Health Survey (SF-36) is an instrument that has been widely used in outpatient populations to determine functional status. Our objectives were to describe the usefulness of the SF-36 in CFS patients and to determine if subscale scores could distinguish patients with CFS from subjects with unexplained chronic fatigue (CF), major depression (MD), or acute infectious mononucleosis (AIM), and from healthy control subjects (HC). An additional goal was to ascertain if subscale scores correlated with the signs and symptoms of CFS or the presence of psychiatric disorders and fibromyalgia.

Design
Prospectively collected case series.

setting
Patients with CFS and CF were seen in a university-based referral clinic and had undergone a complete medical and psychiatric evaluation. Other study subjects were recruited from the community to participate in research studies.

Participants
The study included 185 patients with CFS, 246 with CF, 111 with AIM, and 25 with MD. There were 99 HC subjects.

Measures
The SF-36 and a structured psychiatric interview were used. The SF-36 contains 8 subscales: physical, emotional, social, and role functioning, body pain, mental health, vitality, and general health—and a structured psychiatric interview.

Results
Performance characteristics (internal reliability coefficients, convergent validity) of the SF-36 were excellent. A strikingly consistent pattern was found for the physical functioning, role functioning, social functioning, general health, and body pain subscales, with the lowest scores in CFS patients, intermediate scores in AIM patients, and the highest scores in the HC subjects. The CFS patients had significantly lower scores than patients with CF alone on the physical functioning (P ≤0.01), role functioning (P ≤0.01), and body pain (P≤0.001) subscales. The emotional functioning and mental health scores were worst among those with MD. The presence of fibromyalgia, being unemployed, and increasing fatigue severity all were associated with additional functional limitations across multiple functional domains, with increasing fatigue appearing to have the greatest effect.

Conclusions
The SF-36 is useful in assessing functional status in patients with fatiguing illnesses. Patients with CFS and CF have marked impairment of their functional status. The severity and pattern of impairment as documented by the SF-36 distinguishes patients with CFS and CF from those with MD and AIM, and from HC, but does not discriminate between CF and CFS.

https://www.sciencedirect.com/science/article/abs/pii/S0002934396002343

 

Note: I have added this paper as it's currently being looked at as part of the response to the paper by Walitt et al (see https://www.s4me.info/threads/use-o...s-2024-walitt-et-al.37463/page-30#post-524230).

 

Cohort recruitment

CFS patients were recruited from the University of Washington Chronic Fatigue Clinic and the clinic accepts both self- and physician referrals and patients underwent a standardised medical examination. Patients were classified as having CFS if they met the modified 1988 CDC case definition, which however does not exclude patients with most psychiatric disorders.

People with chronic fatigue had no recognised medical condition however didn’t meet the CDC criteria from 1988 due to an inadequate number of symptoms.

Fibromyalgia was diagnosed according to standard guidelines. The AIM cohort was part of a different study, whilst MD where recruited via advertisements (MD patients were diagnosed with MD however were currently not seeking medical or mental health care). Healthy controls were recruited from other studies.

SF-36 results

Patients with CFS scored lower than HC on every of the 8 SF-36 sub scales. Additionally there was a larger discrepancy between the SF-36 physical function sub scale between CFS patients and HC.

 

These days, any use of the word "functioning/functional" makes me approach what is written with extreme caution. Are they using the word in the way a normal non-medical person would? E.g. I have a functioning fridge. Or are they using it with the medical usage which is "functioning/functional means whatever I want it to mean"?