CFS: A Review of Epidemiology and Natural History Studies

Almost all studies with samples of patients who have chronic fatigue syndrome (CFS) have relied on referrals from physicians or health facilities. Under-served minorities, who not only tend to manifest higher levels of chronic illness, but are also less likely to seek and receive adequate medical care, have not been represented in these studies (1). This may have contributed to an under-estimation of CFS among minority groups (2). Few studies have derived their samples from socioeconomically and ethnically diverse community-based populations. A technical report issued by the Agency for Healthcare Research and Quality (3) concluded that estimating rates of recovery/improvement or relapse from CFS are not possible because there are so few natural history studies and those that are available have involved selected referral populations. This paper provides a review of epidemiologic studies of CFS followed by a discussion of diagnostic issues and risk factors for the illness. Findings from Jason et al.'s (4) epidemiologic study in a multi-ethnic, economically diverse urban area are highlighted as this research group is now examining the natural course of CFS over the past 10 years with this community-based sample. The current study will add to current epidemiologic and risk factors research by assessing the course, progression, and risk factors of CFS among a demographically diverse sample of participants who are unbiased by illness, help-seeking behaviors, or differential access to the health care system.