ABSTRACT
The frailty criteria, focused on physical function, are necessary for definitional purposes and have made a strong case for using predominantly physical elements. However, it is argued that the functional approach to the geriatric patient makes it difficult to isolate physical from cognitive performance. Frailty has been operationalised as a disorder of physical function, but several groups have proposed including cognitive impairment as a frailty criterion. The development of 'minimal cognitive impairment' was stimulated first by the clinical awareness of the existence of a grey zone of cognitive impairment that was not captured by any clinical definition and by the rising awareness of dementia as an important area of public health. Sociologists have played a central role in establishing the link between social relationships and health outcomes, identifying explanations for this link and discovering social variation at the population level. Social relationships – both quantity and quality – affect mental health, health behaviour, physical health and mortality risk.
