Strengths and weaknesses of the evaluation
migraine, TTH
MIGRAINE
Our process evaluation was extensive and followed a published protocol. Our assessment of the fidelity of the intervention was comprehensive. The interview sample may not be large enough to capture the diversity of ways participants responded to the intervention. GP feedback was limited due to the COVID pandemic. Evaluation of the one-to-one sessions was limited to clinical record forms. Nearly one third of those in the intervention arm did not attend enough to achieve our definition of “partial adherence”, this could, potentially, have diluted the effects of the intervention. Finally, whilst we approached a large population the trial failed to identify and recruit those with TTH without co-existent migraine and as a result was predominantly those with migraine.