Quality of life instruments for economic evaluations in health and social care for older people: a systematic review

Gaining health may not be the main goal of healthcare services aimed at older people, which may (also) seek to improve wellbeing. This emphasizes the need of finding appropriate outcome measures for economic evaluation of such services, particularly in long-term care, capturing more than only health-related quality of life (HrQol). This review assesses the usefulness of HrQol and wellbeing instruments for economic evaluations specifically aimed at older people, focusing on generic and preference-based questionnaires measuring wellbeing in particular. We systematically searched six databases and extracted instruments used to assess HrQol and wellbeing outcomes. Instruments were compared based on their usefulness for economic evaluation of services aimed at older people (dimensions measured, availability of utility scores, extent of validation). We identified 487 articles using 34 generic instruments: 22 wellbeing (two of which were preference-based) and 11 HrQol instruments. While standard HrQol instruments measure physical, social and psychological dimensions, wellbeing instruments contain additional dimensions such as purpose in life and achievement, security, and freedom. We found four promising wellbeing instruments for inclusion in economic evaluation: Ferrans and Powers QLI and the WHO-Qol OLD, ICECAP-O and the ASCOT. Ferrans and Powers QLI and the WHO-Qol OLD are widely validated but lack preference-weights while for ICECAP-O and the ASCOT preference-weights are available, but are less widely validated. Until preference-weights are available for the first two instruments, the ICECAP-O and the ASCOT currently appear to be the most useful instruments for economic evaluations in services aimed at older people. Their limitations are that (1) health dimensions may be captured only partially and (2) the instruments require further validation. Therefore, we currently recommend using the ICECAP-O or the ASCOT alongside the EQ-5D or SF-6D when evaluating interventions aimed at older people.