Complex sentence: The questionnaire contains questions pertaining to the applicant's activity before and after s/he became disabled, including what his/her daily activities are, and how the disability has affected his/her ability to perform them.
Split into simpler sentences: The questionnaire contains questions pertaining to the applicant's activity before and after s/he became disabled. The questions that are asked include what his/her daily activities are and how the disability has affected his/her ability to perform them.