Chronic headache after aneurysmal subarachnoid hemorrhage (aSAH) remains an ongoing area of investigation, with uncertainty regarding its prevalence and long-term outcomes.

A systematic review was conducted across five databases – Medline (Ovid), the Cochrane Central Register of Controlled Trials (Ovid), PsychInfo (Ovid), Embase (Ovid) and Scopus (Elsevier) – to identify all studies investigating the prevalence of chronic headaches after aSAH. A total of five studies were identified and included in our review.

There were five observational studies (three cohort and two cross-sectional). The overall prevalence of chronic headaches after aSAH ranged from 16.1% to 41%, albeit across a follow-up time frame of 12 months to 7.5 years. Outcome measurements included quantitative pain scores and opioid usage; however, these were inconsistent across studies, and the studies did not address the long-term impacts of chronic headaches on quality of life or their psychosocial implications.

The prevalence of chronic headache after aSAH is not well-characterized, and long-term outcomes are seldom studied, highlighting a critical gap in the current literature. Longitudinal cohort studies with standardized approaches to ascertain the psychosocial and physiological burden associated with post-aSAH chronic headaches are urgently needed.

Patient and public involvement (PPI) plays a crucial role in ensuring research is carried out in conjunction with the people that it will impact upon. In this article, we present our experiences and reflections from working collaboratively with patients and public through the lifetime of an National Institute for Health Research (NIHR) programme grant; the Chronic Headache Education and Self-management Study (CHESS) which took place between 2015 and 2020.

We worked closely with three leading UK migraine charities and a lay advisory group throughout the programme. We followed NIHR standards and used the Guidance for Reporting Involvement of Patients and the Public checklist. We consulted our PPI contacts using a variety of methods depending on the phase of the study and the nature of the request. This included emails, discussions, and face-to-face contact.

PPI members contributed throughout the study in the programme development, in the grant application, ethics documentation, and trial oversight. During the feasibility study; in supporting the development of a classification interview for chronic headache by participating in a headache classification conference, assessing the relevance, and acceptability of patient-reported outcome measures by helping to analyse cognitive interview data, and testing the smartphone application making suggestions on how best to present the summary of data collected for participants. Due to PPI contribution, the content and duration of the study intervention were adapted and a Delphi study with consensus meeting developed a core outcome set for migraine studies.

The involvement of the public and patients in CHESS has allowed us to shape its overall design, intervention development, and establish a core outcome set for future migraine studies. We have reflected on many learning points for the future application of PPI.