Objective: To determine the prevalence of chronic fatigue syndrome (CFS) in general practice.
Setting: General practice and primary health care centres in Leyden region, the Netherlands.
Method: RNUH-LEO is a computerized database which contains the anonymous patient information of one general practice (with two practitioners) and four primary health care centres. The fourteen participating general practitioners were asked what International Classification of Primary Care (ICPC) code they used to indicate a patient with chronic fatigue or with CFS. With these codes and with the code for depression patients were selected from the database. It then was determined whether these patients met the criteria of CFS by Holmes et al.
Results: The general practitioners used 10 codes. Including the code for depression a total of 601 patients were preselected from a total of 23,000 patients in the database. Based on the information from the patients' records in the database, 42 of the preselected patients were selected who might fulfill the Holmes' criteria of CFS. According to the patients' own general practitioner, 25 of the 42 patients would fulfil the Holmes' criteria. The men:women ratio was 1:5. The prevalence of CFS in the population surveyed was estimated to be at least 1.1 per 1,000 patients.