It would seem obvious to most people that the more illnesses one has, the less functional they would be. Scientists, on the other hand, must prove things via empirical studies.In a study titled Functioning in individuals with chronic fatigue syndrome: increased impairment with co-occurring multiple chemical sensitivity and fibromyalgia, Brown and Jason (2007) set out to "differentiate these diagnoses by comparing individuals with one or more illnesses on functioning, psychiatric comorbidity, coping style, and in vivo physical measures".
Brown and Jason were spurred by the proposal that chronic fatigue syndrome (CFS), multiple chemical sensitivity (MCS), and fibromyalgia (FM) commonly co-occur and may be manifestations of the same illness.
The researchers surveyed 114 men and women who met the criteria for CFS. They further diagnosed FM during a physical examination, and MCS using a questionnaire. The men and women were then divided into four groups based on diagnoses:
43.9% met criteria for CFS,
23.7% met criteria for CFS & MCS, 15.8% met criteria for CFS & FM,
16.7% met criteria for all three.
Demographics varied widely. A total of 46% were referred by physicians, 34% from media advertisements, and 20% from word-of-mouth.
After an initial screening, participants were given a CFS questionnaire to collect demographics, health status, medication usage, and symptom data. This was followed by a structured clinical interview for DSM-IV (Diagnostic and Statistics Manual of Mental Disorders) disorders to determine presence of any mental disorders. A medical assessment of CFS was performed, including an in-depth medical and neurological history, and physical exam. A self-report measure was used for general functioning. The Fatigue Severity Scale was added to measure fatigue and the Beck Depression Inventory was included to measure depression.
A Brief Cope and Brief Pain was administered to determine how subjects reacted to stress and pain respectively. An Actiograph, designed to measure activity during every minute of a week was worn to record daily activities. A six minute walking test measured physical functioning and the Rating of Perceived Exertion was used to measure subjects perception of the intensity of their activity based on bodily sensations. Sit and reach, hand grip, and employment status were the final factors examined that concluded this extensive battery of measures.
As you undoubtedly guessed, the more conditions the subject had, the more impaired they were. Those with CFS alone were the highest functioning and those with CFS, FM, and MCS were the lowest functioning, leading Brown and Jason to conclude that "this study provides evidence that having more than one illness exacerbates one's disability beyond CFS alone", which we have already guessed would be the case.
No significant differences were found in varying socio-demographic categories. A rather large percent of subjects (68%) had a college degree or higher, suggestive of prior functioning.
A substantial number of CFS patients (56%) had co-occurring MCS and/or FM, which is consistent with prior study findings that have shown significant overlap between MCS, CFS, and FM.
As you undoubtedly guessed, the more conditions the subject had, the more impaired they were. Those with CFS alone were the highest functioning and those with CFS, FM, and MCS were the lowest functioning, leading Brown and Jason to conclude that "this study provides evidence that having more than one illness exacerbates one's disability beyond CFS alone", which we have already guessed would be the case.
No significant differences were found in varying socio-demographic categories. A rather large percent of subjects (68%) had a college degree or higher, suggestive of prior functioning.
A substantial number of CFS patients (56%) had co-occurring MCS and/or FM, which is consistent with prior study findings that have shown significant overlap between MCS, CFS, and FM.
Depression was more common in those with MCS, CFS, and FM combined, suggesting increased prevalence of depression in those who are more severely disabled.
Overall, this exhaustive study has shown that increased disability means decreased functioning. It is important to remember that all participants in this study suffered from CFS. FM and MCS was not evaluated alone or as a pair without the presence of CFS.
-LS
Reference:
Brown, MM & and Jason, LA (2007). Functioning in individuals with chronic fatigue syndrome: increased impairment with co-occurring multiple chemical sensitivity and fibromyalgia. Dynamic Medicine 2007, 6:6
