MEASUREMENT ISSUES AND RELATED CLASSIFICATIONS
38. The collection of the variable 'Age' is necessary to determine whether or not a person has an Education/employment restriction. If the person is aged 65 years or more, they are not required to answer the questions on employment and education restrictions.
39. In most circumstances the determination of 'Severity of disability' is dependent on a respondent's perception of their need for help, and their interpretation of the meanings of 'help', 'supervision', 'difficulty', 'restriction', and 'everyday activity'. No other specific measurement issues apply to the variable 'Severity of disability' beyond the normal constraints affecting statistical collections, such as problems with confidentiality or standard errors which may not permit the output of data for some of the categories at the more detailed levels of the classification.
40. The classification for 'Severity of disability' is used to derive profound or severe core activity limitation relatable to 'Core activity need for assistance' when using the interviewer-based collection module.