The value of nonfactual information in distinguishing primary from secondary headache disorders results of a Delphi study

Objective: To collect pairs of nonfactual information and their interpretations and rate their usefulness in distinguishing between primary and secondary headache disorders. Background: Physicians use clinical indicators such as Red Flags and ask about exposure to potential causes to differentiate primary from secondary headaches; however, these approaches have limitations and may result in unnecessary diagnostic procedures. Methods: Using the Delphi process, the participants proposed information-interpretation pairs in the first round and rated them anonymously in two subsequent rounds. The ratings relied on quality estimators to evaluate the reliability, validity, relevance, and frequency on 5-point Likert scales, ranging from 0 to 5. We considered pairs with an average rating of 4.0 or higher to have reached consensus. Results: Four proposals reached consensus, of which two referred to nonfactual information: (i) “A headache that feels familiar indicates a primary headache.” (ii) “A headache that feels completely different from any previous headache raises the suspicion of a secondary headache.” Conclusions: The participants generally found little use for nonfactual information for distinguishing between primary and secondary headache disorders. Solely the presence and absence of patients’ notion of a familiar headache were deemed helpful. While the participants viewed the former as being associated with a primary headache, they felt that the latter pointed towards a secondary headache. Further research is necessary to evaluate their usefulness in clinical practice.