Which strategy should be applied? Design of a Norwegian epidemiological survey on chronic headache

Large-scale population-based epidemiological surveys on chronic headache based on clinical interview by a physician are lacking.

To describe a method that aims to provide valid information on chronic headache.

A self-administered questionnaire including two questions about headache frequency within the last month and within the last year was used to screen for possible chronic headache. Respondents with self-reported headache more than half of the days were interviewed by neurological residents with experience in headache diagnostics.

Previous studies have shown that a single question from a self-administered questionnaire can be used to screen for chronic headache. However, a precise headache diagnosis requires an interview by a physician experienced in headache diagnostics, as diagnoses extracted from questionnaires or provided by lay interviewers are not sufficiently precise.

A combination of a screening questionnaire and a clinical interview by a physician is likely to be a cost-effective method to conduct an epidemiological survey on chronic headache.