Research report Which measure of quality of life performs best in older age? A comparison of the OPQOL, CASP-19 and WHOQOL-OLD < Additional informations are published online only. To view these ﬁles please visit the journal online (http://jech.bmj.com). 1Faculty of Health and Social Care Sciences, Kingston University & St George’s, University of London, UK 2School of Applied Social Sciences, University of Brighton, Sussex, UK Correspondence to Professor Ann Bowling, Faculty of Health and Social Care Sciences, Kingston University & St George’s, University of London, Cranmer Terrace, London, SW17 ORE, UK; a.bowling@sgul.kingston.ac.uk This work was completed whilst the corresponding author was at Department of Primary Care and Population Sciences, University College London, Hampstead Campus, London, UK Accepted 30 November 2009 Published Online First 18 August 2010 This paper is freely available online under the BMJ Journals unlocked scheme, see http:// jech.bmj.com/site/about/ unlocked.xhtml Ann Bowling,1 Paul Stenner2 ABSTRACT Background Most measures of quality of life (QoL) are based on ‘expert’ opinions. This study describes a new measure of QoL in older age, the Older People’s QoL Questionnaire (OPQOL), which is unique in being derived from the views of lay people, cross-checked against theoretical models for assessment of comprehensiveness. Its performance was assessed cross-sectionally and longitudinally. It was compared with two existing QoL measures in the cross-sectional studies in order to identify the optimal measure for use with older populations. Methods Data were taken from three surveys of older people living at home in Britain in 2007e2008: one population survey of people aged 65+, one focused enumeration survey of ethnically diverse older people aged 65+, one follow-up of a population survey of people aged 65+ at baseline in 1999/2000. Measures were QoL (using OPQOL, Control, Autonomy, Satisfaction, Pleasure - 19 items (CASP-19), World Health Organization Quality of Life questionnaire - version for older people (WHOQOL-OLD)), health, social and socioeconomic circumstances. The CASP-19 and WHOQOL-OLD were not administered to the longitudinal sample in order to reduce respondent burden. Results Psychometric tests were applied to each QoL measure. The OPQOL, CASP-19 and WHOQOL-OLD performed well with the cross-sectional samples; however, only the OPQOL met criteria for internal consistency in the Ethnibus samples. Conclusion The OPQOL is of potential value in the outcome assessment of health and social interventions, which can have a multidimensional impact on people’s lives. Further research is needed to examine whether differences by ethnicity reﬂect real differences in QoL, methodological issues, variations in expectations or cultural differences in reporting. BACKGROUND Governments across the developed world are concerned with enabling older people to maintain their active contribution to society, and thereby their quality of life (QoL).1 QoL has become a commonly used end point in the evaluation of multisector public policy, including health, social, community and environmental policy actions. For policy outcomes to be measured with any validity, measures of QoL need to have social, as well as policy, relevance, to be meaningful to people’s lives, and to be carefully conceptualised and constructed. Lawton2e6 developed a popularly cited quadri- partite concept of QoL, proposing that the ‘good life’ (QoL) may be represented by behavioural and social competence (health, cognition, time use, social behaviour), perceptions of QoL (subjective evalua- tion of each domain of life), psychological well-being (mental health, cognitive judgements of life satis- faction, positive‑negative emotions) and the external, objective, physical environment (housing, economic indicators). However, there is no consensus about its conceptual deﬁnition or measurement,7 and most investigators have based their concepts on expert opinions rather than the perspectives of lay people. This has the consequence that there are few empirical data on the extent to which the items included in measurement scales have any relevance to people. Thus, it is increasingly important to develop a multidimensional model and measure of quality of life, for use in descriptive and evaluative multisector policy research, which reﬂects the views of the population concerned, with cross- sectional and longitudinal applicability. Elicitation of people’s own views of QoL in this process is partic- ularly important because QoL is a subjective concept. What are older people’s views of QoL? Survey and qualitative research with people aged 65+, living at home in Britain, reported that the central planks of QoL emphasised by respondents were psychological well-being and positive outlook, having health and functioning, social relationships, leisure activi- ties, neighbourhood resources, adequate ﬁnancial circumstances and independence.7e10 This research led to the development of the Older People’s Quality of Life Questionnaire (OPQOL), which is unique in being derived from the views of a representative sample of older people, cross-checked against theo- retical models for assessment comprehensiveness. METHODS The aim here is to compare the psychometric properties of the OPQOL, with the CASP-19 and WHOQOL-OLD among people 65+ participating in three national surveys of older people living at home in Britain. Two of these three surveys were cross-sectional, and the third was longitudinal (see supplementary Appendix 1): 1. Ethnibus survey of people aged 65+ responding to two waves of the national Ethni Surveys (http://www.ethnicfocus.com) in 2008. This is a rolling face-to-face interview survey with adults aged 16+, living at home, based on focused enumeration, stratiﬁed random sampling of postcodes in Britain, and statistically robust sampling of people in common ethnic minority groups in Britain; the response rate was 70% (n¼400). 2. ONS survey of people aged 65+ responding to two waves of the Ofﬁce for National Statistics J Epidemiol Community Health 2011;65:273e280. doi:10.1136/jech.2009.087668 273