[Protective effects of social networks on disability among older adults in Madrid and Barcelona, Spain, in 2005].

Background: The loss of autonomy at advanced ages is not only associated with ageing, but also with the characteristics of the physical and social environment. Recent investigations have shown that social networks, social engagement and participation act like predictors of disability among the elderly. To analyze the effect of social networks on the level of autonomy (instrumental and basic disability) at initial stages of the old age.