The frequency of the chronic fatigue syndrome in patients with symptoms of persistent fatigue.

STUDY

OBJECTIVE

To determine the frequency of the chronic fatigue syndrome among patients with symptoms of fatigue.

DESIGN

Prospective, cohort study.

SETTING

Referral clinic, based in a primary care general internal medicine faculty practice of a university medical center.

PATIENTS: Consecutive sample of 135 patients (53 men, 82 women) with 6 months or more of debilitating fatigue.

INTERVENTIONS: All patients had a complete history taken, had a physical examination and a comprehensive battery of blood tests, and were given the Diagnostic Interview Schedule of the National Institute of Mental Health, a highly-structured 260-item instrument designed to enable accurate psychiatric diagnoses. Other diagnostic studies (for example, sleep studies and electroencephalography) were ordered if necessary for individual patients.

MEASUREMENTS AND MAIN

RESULTS

Six of the one hundred thirty-five patients met criteria for chronic fatigue syndrome (95% CI, 0 to 10). Ninety-one (67%) patients (CI, 56 to 78) had clinically active psychiatric disorders and 4 (3%) patients (CI, 0 to 8) had medical disorders that were considered a major cause of their fatigue. Thirty-four (25%) patients (CI, 14 to 36) had insufficient symptoms or objective findings of the chronic fatigue syndrome.

CONCLUSION

The chronic fatigue syndrome is rare among patients with symptoms of persistent fatigue. Most of these patients have psychiatric disorders.