The current generation of ageing adults expects to age well, and to maintain their general well-being and, ultimately, enhance the quality of later life. Most people aged 50 and 65 and more rate themselves as ageing well, or successfully, and few rate as high their chances of becoming housebound, losing their memory or entering a nursing home [1
]. These positive perspectives reflect a shift away from a predominantly pathological perspective of later life, which exaggerated the extent to which chronic ill-health could be attributed to ageing, and which largely ignored the heterogeneity of the older population. A more positive view of old age sees it as a period of opportunity and well-being, with retention, or development, of the psychological resources to cope with life's challenges [3
]. This coincides with world-wide policy interest in the promotion of physical and mental well-being in populations, and the compression of morbidity into fewer years of later life, driven by concerns about increasing expenditure on health and social care in an ageing society. Although there is an awareness that well-being has no clearly defined opposite, and that it is more than the absence of 'ill-being', there are no agreed definitions, other than that it is a 'good thing' [4
]. Policy guidance, including that in the UK, prefers to focus on specific aspects of well-being that are potentially amenable to known interventions, including physical activity (e.g. exercise) to maintain mental and physical functioning, hence well-being [6
], rather than as a dynamic, multi-faceted state which includes more complex subjective, social, and psychological dimensions. There are however exceptions to such reductionist views [7
]. For example, NHS Scotland (2006) [8
] defined the state of mental well-being broadly, encompassing subjective and psychological feelings of life satisfaction, optimism, self-esteem, mastery and feeling in control, having a purpose in life, a sense of belonging and support. This is more consistent with the long tradition of social research on general well-being, dating back to the 1950s [1
The current, international policy focus on promotion of well-being has stimulated interest in quality of life (QoL) as an outcome indicator. QoL has long been used as an outcome measure in the evaluation of a diverse range of health and social care interventions. It is a multi-faceted, concept, encompassing macro societal and socio-demographic influences and also micro concerns, such as individuals' experiences, social circumstances, health, values and perceptions [1
]. As it is subjective, it needs grounding in people's own values and perceptions.
Much of the focus on how to enhance the quality of later life has been on the achievement of successful ageing, by promoting different approaches, ranging from biomedical, as in the MacArthur Studies of Successful Aging [9
], to broader social,-psychological and lay-based approaches [3
]. These overlap with concepts of 'active ageing' [13
]. The criteria necessary for achieving successful ageing, described in the literature, can be grouped into five approaches: biological (i.e. 'health'), broader biological (i.e. health and social engagement), social, psychological and lay. These have have been reviewed in detail in a cross-disciplinary systematic review of successful ageing [3
], and their construction for the research reported here is summarised next (the measurement scales are described later under Methods):
• Biomedical (i.e. health): Comprised summing of: having diagnosed, chronic medical conditions (actual number reported); ability to perform activities of daily living (ADL) (originally no/little difficulty was originally scored <10, with the remainder scoring a range of levels of difficulty); psychiatric morbidity measured using the General Health Questionnaire-12 (GHQ-12) (original caseness was scored as 5 or more, with no problems as 0-4).
• Broader biomedical (i.e health and social engagement): Comprised summing of the above plus number of different social activities engaged in during past month (3+), as an index of social engagement.
• Social functioning: Comprised summing of number of different social activities engaged in during past month, frequency of social contacts, number of helpers/supporters.
• Psychological resources: Comprised summing of self-efficacy score (best score was less than an original score of 11), best optimism score (of less than an original score of 6), plus GHQ-12 items on sense of purpose: playing useful part; coping: facing up to problems, overcoming difficulties; self-esteem: feels has self-confidence and has self-worth.
• Lay: Comprised summing of the above (note: GHQ-12 items were counted once only given their overlap across models, to avoid singularity being violated by double summing), plus gross annual income and perceived social capital [rating of area facilities (e.g. transport, closeness to shops, services), area problems (e.g. crime, vandalism, graffiti, speed and volume of traffic, air quality), somewhere nice to go for a walk, feels safe walking alone during the day or night].
Biological (or health) approaches to achieve successful ageing have been defined as the avoidance of disease and risk factors, maintenance of physical and cognitive functioning and active engagement with life [9
]. Some biological appraoches are broader, also including numbers of different social activities engaged in during past month (i.e. health and social engagement). Current social approaches include maintenance of high levels of social activity, interaction and participation [14
]; and psychological approaches emphasise psychological resources for coping with the challenges of ageing over time (e.g. perceived self-efficacy, control over life, ability to compensate for declining abilities [15
]. While biological approaches have been the most often investigated [3
], broader approaches, including psycho-social factors accord more closely with lay views of successful ageing [2
] that include income and environmental quality and safety. In cross-sectional analyses such broader biological approaches are also associated with people's self-rated quality of life [12
]. These have been reviewed in depth by Bowling [3
In earlier work on alternate criteria of successful ageing, we reported that broader approaches predicted self-rated QoL more powerfully than unidimensional approaches, and should be used to evaluate the outcomes of health promotion interventions in the older population [12
]. This paper investigates the predictive ability of these different biological, psychological and social approaches of successful ageing on QoL over time, using a national random sample of people aged 65 and over who were followed up 7-8 years later.