Assessing the impact of headaches and the outcomes of treatment: A systematic review of patient-reported outcome measures (PROMs).

Aims To critically appraise, compare and synthesise the quality and acceptability of multi-item patient reported outcome measures for adults with chronic or episodic headache. Methods Systematic literature searches of major databases (1980-2016) to identify published evidence of PROM measurement and practical properties. Data on study quality (COSMIN), measurement and practical properties per measure were extracted and assessed against accepted standards to inform an evidence synthesis.