Understanding Society User Support

It's not clear to me if a subject is asked the below question (on the disability module) only upon entering the survey (their first survey) or instead on their first survey as well as on every subsequent survey? Thank you for any help you can give.

Variable name: _disdif1 … _disdif12

(Type of impairment or disability)
Q: Does this/Do these health problem(s) or disability(ies) mean that you have substantial difficulties with any of these areas of your life? Please read out the numbers from the card next to the ones which apply to you. (12 impairments responses listed):
Mobility (moving around at home and walking); lifting, carrying or moving objects; manual dexterity (using hands to carry out everyday tasks); continence (bladder and bowel control); Hearing (apart from using a standard hearing aid); Sight (apart from wearing standard glasses); Communication or speech problems; memory or ability to concentrate, learn or understand; recognising when you are in physical danger; your physical co-ordination (e.g. balance); difficulties with own personal care; other health problem or disability; None of these