TABLE 1.

Guidelines for headache and chronic pain clinical trials

Guidelines	Primary outcomes Headache	Recommended measures (when provided)	Secondary outcomes	Recommended measures (when provided)
Guidelines for pharmacological headache trials (14)	Percentage of patients pain-free at 2 h Sustained pain-free Frequency	Number of patients pain-free at 2 h with no use of rescue medication or relapse within 48 h Number of attacks per four-week period	Headache intensity Headache relief Time to meaningful relief Global evaluation of medication Functional disability Presence of photo/phonophobia Patients’ preference for treatment Consistency of effect	Verbal/numerical rating scale (0 = no headache; 1 = mild headache; 2 = moderate headache; 3 = severe headache). Percentage of patients with a decrease in headache from severe or moderate to none or mild within 2 h Simple verbal scale Categorical verbal/numerical scale (0 = no disability; 1 = performance of daily activities mildly impaired; 2 = performance of daily activities moderately impaired; 3 = performance of daily activities severely impaired) At least three-quarters of attacks consecutively treated with active drug
	Migraine
	Frequency	Number of attacks per four-week period	Headache intensity Headache duration Drug consumption for symptomatic treatment Patient preferences	Same as headache Number of migraine attacks per four-week period treated with symptomatic treatment/number of tablets per four-week period
	Episodic
Guidelines for behavioural headache trials (15)	Frequency	Number of attacks per month	Headache index Headache duration Peak headache severity Functional status Quality of life Medication use Patient preferences Psychological symptoms	Missed work/school Headache-specific quality of life
	Chronic
	Frequency	Headache days per month	Headache index Number of severe headache days per month Headache duration Peak headache severity Functional status Quality of life Patient preferences Psychological symptoms	Same as episodic
Guidelines for chronic pain clinical trials (12,13)	Pain intensity Physical functioning Emotional functioning Role functioning Symptoms and adverse events Global judgement of satisfaction with treatment Sleep Economic factors	11-point (0–10) numerical rating scale of pain intensity Multidimensional Pain Inventory Interference Scale OR Brief Pain Inventory interference items Beck Depression Inventory OR Profile of Mood States School attendance, PedMIDAS, PedsQL* Passive capture of spontaneously reported adverse events and symptoms and use of open-ended prompts Sleep diary, Sleep Habits Questionnaire*

*Pediatric recommendations. PedMIDAS Pediatric Migraine Disability Assessment; PedsQL Pediatric Quality of Life Inventory