Assessment of quality of life in later life: Development and validation of the QuiLL

The aim was to develop a quality of life (QOL) instrument, informed by older people, carers and professionals in older peoples' services, for use by community care staff as part of their assessment, care-planning and outcome monitoring procedures. The multi-phase development project involved: qualitative interviews to generate the item pool; pre-testing; preliminary field-testing; and final testing in a community survey and in health and social care settings. The process was informed by over 100 interviews with older people, carers, professionals, academics and policy-makers. Two products emerged following data-reduction: a research instrument (64 items), and a shorter assessment tool suitable for routine use in clinical, therapeutic or case-management practice (27 items, taking 7-15 min to complete). A community survey using the research instrument achieved a 71 response rate (n=249). Ninety six percent of people found the domain content of the assessment tool relevant, and 80 considered the items covered were important. Both instruments have good internal consistency (alpha=0.85). Inter-rater reliability was good for research staff, but poor between them and operational staff. Little objective change took place during the 3-month follow-up study, but where it did the direction was consistent with subjective change. The instrument needs to be applied in different contexts to assess interventions of known impact. Together with daily living and health status measures it can form part of a comprehensive assessment for older people.