Chronic Fatigue Syndrome - More Common Than Doctors Think?

Summarized by Robert W. Griffith, MD
December 10, 2004

Introduction

Many people seem to be tired all the time, but only a few are diagnosed with the Chronic Fatigue Syndrome (CFS). To be diagnosed with this disabling condition a person must have had symptoms for at least 6 months, and fulfill at least 4 of 8 specific conditions:

• Unusual fatigue after exertion lasting 24 hours
• Impaired memory or concentration
• Unrefreshing sleep
• Sore throat
• Tender lymph nodes
• Muscle pain
• Joint pain
• Headaches

To make it harder, there's no test or specific lab results to confirm the diagnosis. Using these criteria, it's been estimated that between half a million and a million adults in the USA have CFS.¹ However, a newly published study shows that most cases in the population aren't recognized as such by their doctors. It's been published in the Archives of Internal Medicine, and we summarize the findings here.

What was done

A computer-assisted telephone interviewing system was used to screen approximately 90,000 Wichita, Kansas, residents. Those with severe fatigue lasting more than one month, as well as an equal number of randomly-selected non-fatigued people, had detailed phone interviews at annual intervals, for 4 years.

Those meeting the CSF criteria given above had a full clinical examination. Care was taken to exclude anyone with medical or psychiatric conditions that could explain their symptoms. They were then classified into two groups: those who had been previously diagnosed with CFS by their doctor, and those who had not. Analyses were done to define the differences between the two groups.

What was found

The 90 people with CFS were mostly women (86%), over 40, and overweight. Only 18% had graduated from a 4-year college, 44% had a household income over $40,000 a year, and 14% fell below the poverty line.

Of the 90 CFS subjects found by the survey, 14 (16%, all women) had previously been diagnosed with the condition by their doctor. Incomes were significantly different between the two groups - those with moderate incomes ($15,000 - $40,000 annual household income) were more likely to have been diagnosed than those with higher incomes.

The characteristics of the group of people previously diagnosed with CFS differed from those not diagnosed by a health professional in the following ways:

• Sudden onset of fatigue, rather than gradual
• All 8 of the 'signal' criteria for diagnosis present
• Tender lymph nodes present
• Sore throat present

Although only 21% of the overall subjects with CFS had a sudden onset of fatigue, they made up half of those who had been previously diagnosed. Tender lymph nodes and sore throat were relatively uncommon overall (about 20%), but they were reported in about half of those previously diagnosed with CFS.

What this means

It's rather worrying that so many people (84%) with CFS were not actually diagnosed with the condition. It seems likely that the symptoms the diagnosed people had to a greater degree (sudden onset, sore throat, tender glands) were more likely to send them to the doctor. And perhaps those in the higher annual income group were so busy at their jobs they didn't have time to go to the doctor!

Although there is no standardized treatment for CFS (perhaps because the cause is unknown), the diagnosis is important. At the very least, different therapies can be prescribed to try to alleviate symptoms. And then, some people go from doctor to doctor in search of a diagnosis; it's helpful to them to have resolution of this problem. Finally, it must be recognized that CFS is a debilitating condition, rated by some as more severe than end-stage renal disease, heart disease, or multiple sclerosis. Appropriate sick leave and disability benefits should be made available.

Be sure to visit the CDC link below (the first), which gives a good run-down on the present approaches to treatments that are likely to be helpful.

Source

• Factors influencing the diagnosis of chronic fatigue syndrome. L. Solomon, WC. Reeves, Arch Intern Med, 2004, vol. 164, pp. 2241--2245

Footnotes
1. Prevalence and incidence of chronic fatigue syndrome in Wichita, Kansas. M. Reyes, R. Nisenbaum, DC. Hoaglin,  et al., Arch Intern Med, 2003, vol. 163, pp. 1530--1536

Related Links
CDC: Chronic Fatigue Syndrome
NIAD: Chronic Fatigue Syndrome