To determine the prevalence of chronic fatigue syndrome (CFS) and of primary fibromyalgia syndrome (PFS) in the Netherlands.
Questionnaire.
Department of Medical Psychology, University Hospital Nijmegen, the Netherlands.
A questionnaire was mailed to all the 6657 general practitioners in the Netherlands in order to inform them of the existence of CFS and to ask them if they had any CFS or PFS patients in their practices.
Sixty percent (n = 4027) of the general practitioners returned the questionnaire. Of all the general practitioners, 27% said they had no CFS patients, 23% said they had 1 CFS patient, while 21% had 2 CFS patients, and 29% said they had 3 or more CFS patients in their practice. Concerning PFS the results were 17% (no PFS patients), 18%, 18% and 47%, respectively. With a mean practice of 2486 patients per general practice, the estimated prevalence of CFS was 112 per 100,000 and that of PFS 157 per 100,000 persons. Of the CFS patients 81% were women and 55% were 25-44 years old; for PFS these figures were 87% and 48% respectively.
Extrapolation of the study results indicates that there are at least 17,000 CFS patients and 24,000 PFS patients in the Netherlands. The found prevalence is probably an under-estimation.