Table 3 Item to total correlations and Cronbach’s alpha for the CHQ scale

Restriction of ADL

 Avoided leaving the house

 Avoided making plans due to unpredictability of CH e.g., holidays

 Felt unable to complete duties at work

 Had difficulty in getting involved in leisure activities e.g., cinema, theatre, etc.?

 Avoided crowded and noisy places e.g., public transport, pubs, etc.

 Felt that the severity of cluster headache affected your daily activities

 Been less involved in family affairs eg interaction with children,planning holidays

 Been unable to socialise/spend time with friends and family

 Been unable to achieve your daily goals and carry out routines and chores

Impact on mood and interpersonal relationships

 Felt less respected by others

 Had problems with close personal relationship

 Felt you were a burden on family and friends

 Felt self-conscious and uncomfortable about your appearance after a cluster headache attack (eg swelling/redness of eyes and facial sweating, etc.)

 Felt that others are dismissive of your cluster headaches

 Felt aggressive

 Felt bad about yourself, lost self-confidence or felt worthless

 Felt like harming yourself or suicidal

 Been irritable, impatient or less tolerant

 Been forgetful e.g., missed appointments

 Been unable to take care of your appearance (eg take a bath, put make-up on, change clothes etc.)

 Felt isolated, lonely or vulnerable

Pain and anxiety

 Found your pain is unbearable if untreated

 Dreaded that the headache would not go away

Lack of vitality

 Felt lacking in energy and constantly tired

 Felt sleepy, worn out or less able to concentrate due to nocturnal attacks of CH

 Had problems concentrating e.g., reading paper, watching TV, etc.

 Been unable to think clearly

 Felt tense or anxious